Download A01 LOCAL INFILTRATION ANALGESIA IN TOTAL

A01
LOCAL INFILTRATION ANALGESIA IN TOTAL HIP ARTHROPLASTY: A PHARMACOKINETIC
STUDY OF KETOROLAC
F. Affas, S. Eksborg, P. Wretenberg, N. Stephanson, C. Olofsson, C.-O. Stiller
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Anesthesia and Intensive Care, Department of Women and Child Health, Orthopedics, Clinical
Pharmacology, Karolinska University Hospital, Stockholm, Sweden
Introduction: Local Infiltration Analgesia (LIA) is widely used in the last decade as a method of
postoperative treatment after lower extremity arthroplasty. In the LIA technique a mixture of a longacting local anaesthetic (ropivacaine), a non-steroidal anti-inflammatory drug (Ketorolac), and
epinephrine are infiltrated intra operatively in all traumatized tissue. This method has certain
advantages, which include administration at the site of traumatized tissue, minimal systemic side
effects, faster postoperative mobilization, earlier postoperative discharge from hospital and less opioid
consumption. However, information regarding plasma concentrations of ketorolac after LIA mixture is
insufficient to predict the risk of renal impairment in patients subjected to arthroplasty. The aim of this
study is to determine the maximal plasma concentration and the exposure of ketorolac during the first
30 h following infiltration in hip arthroplasty.
Methods: In a prospective open trial thirteen patients scheduled for primary total hip arthroplasty
received LIA (ropivacaine 200 mg, ketorolac 30 mg and epinephrine 0.5 mg) in a volume of 106 ml.
Plasma concentration of ketorolac was quantified by liquid chromatography- mass spectrometry (LCMS).
Results: The range of the maximal plasma concentration 0.3 - 2.2 mg/L, was detected 30min - 4
hours after completing the infiltration.
Discussion: In contrast to a common belief, the plasma concentration of ketorolac after LIA is not
negligible, but within the same range as after intramuscular injection of the same dose of ketorolac to
healthy elderly volunteers. Caution should be taken when having ketorolac in LIA as a method in
treating post-operative pain in hip arthroplasty, with specific attention to risk factors that predispose a
patient to renal dysfunction.
References:
1. Aitken, H. A., J. W. Burns, C. S. McArdle and G. N. Kenny (1992). "Effects of ketorolac trometamol
on renal function." Br J Anaesth 68(5): 481-485.2.
2. Brocks, D. R. and F. Jamali (1992). "Clinical pharmacokinetics of ketorolac tromethamine." Clin
Pharmacokinet 23(6): 415-427.3.
3.Jallad, N. S., D. C. Garg, J. J. Martinez, E. J. Mroszczak and D. J. Weidler (1990).
"Pharmacokinetics of single-dose oral and intramuscular ketorolac tromethamine in the young and
elderly." J Clin Pharmacol 30(1): 76-81.
Nothing to disclose
This study was approved by the Regional Research Ethics Committee at the Karolinska Institutet in
Stockholm and by the Swedish Medical Products Agency.
A02
PERSISTENT PAIN AFTER TOTAL KNEE ARTHROPLASTY (TKA): INCIDENCE,
CHARACTERISTICS AND PREDICTIVE FACTORS
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I. Grosu , E. Thienpont , M.-N. France , P. Lavand'homme
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2
2
Anesthesiology, Cliniques Universitaires Saint Luc, Bruxelles, Cliniques Universitaires Saint Luc,
Brussel, Belgium
Background and goals: Chronic pain after surgery (CPSP) may concern a large number of patients,
the major cause being related to surgical nerve trauma (1). Psychological factors play a major role in
the development of CPSP including after a nerve injury. The present study is aimed to identify risk
factors and characteristics of CPSP after TKA, a common surgical procedure.
Methods: After IRB approval and informed consent, patients undergoing primary TKA filled in
preoperatively anxiety (HAD) and catastrophization (RCD) questionnaires. A single surgeon
performed all surgeries under standardized anesthesia protocole. All patients received multimodal
analgesia including single dose 300 mg pregabalin preoperatively. Postoperative pain scores were
recorded from day1to day8 (VAS 0-10) at rest and movement. Patients answered Brief Pain Inventory
(BPI) and neuropathic pain DN4 questionnaires by phone call at 3 months. Statistical analysis used
unpaired t-tests and Pearson's correlation, p< 0.05 was significant.
Results: 62 patients were included; 52 patients (84%) answered the 3 months questionnaire. 62%
had CPSP, 11% presented neuropathic pain features. Average CPSP score was 2 (0-7) and worse
pain 4 (2-9). Neuropathic pain was associated with higher intensity of CPSP. 40% CPSP patients
were taking analgesics with an average pain relief of 60% (20-100%). CPSP and pain free patients at
3 months did not differ for age, gender, BMI, preoperative pain score. However, CPSP patients
presented with significantly higher acute pain scores at mobilisation than pain free patients from day2
to day6. Preoperative catastrophization and anxiety scores did not correlate with CPSP at 3 months
but there was a positive correlation between intensity of acute pain at movement on day3 and day4
and the development of CPSP, specifically neuropathic pain (r = 0.440;p< 0.01).
Discussion-conclusion: Our results are in agreement with the literature showing that CPSP is
frequent after TKA but from low neuropathic origin (2). Acute pain severity during mobilization,
specifically at day3 and day4, may be an interesting predictor of CPSP neuropathic pain after TKA.
The lack of catastrophisation and anxiety scores predictive value might be due to preoperative
pregabalin administration in all patients, an intervention that deserves further studies.
(1) Kehlet et al, Lancet 2006;
(2) Haroutiunian et al, Pain 2013.
A03
EFFECTS OF INTRATHECAL INJECTION OF CAMKⅡ INHIBITOR KN93 ON REMIFENTANILINDUCED HYPERALGESIA IN RATS
X. Gu, Z. Ma, C. Cheng, J. Zhang, W. Zhang
Department of Anaesthesiology, Affiliated Drum Tower Hospital, Medical School of Nanjing University,
Nanjing, China
Introduction: Our previous studies have shown that tyrosine phosphorylation of the NR2B at Tyr1472
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in spinal dosal horn contributes to postoperative hyperalgesia induced by remifentanil .
2+
Calcium/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) can be activated by Ca influx through
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NMDA receptors . This study aimed to investigate the effects of intrathecal injection of CaMKⅡ
inhibitor KN93 on the hyperalgesia induced by remifentanil in a rat model of incisional pain.
Material and methods: All experiments were approved by the Animal Care and Use Committee at
the Medical School of Nanjing University. 75 SD rats were divided randomly into 5 groups (n=15):
group R (rats underwent a surgical incision and remifentanil 0.04mg/kg was infused subcutaneously
at the moment of surgical incision over a period of 30 min), group I (rats underwent a surgical incision
and subcutaneous infusion of the same volume of saline), group C (rats underwent a sham procedure
without an incision), group DMSO (intrathecal injection of 10% DMSO 20µl 30 min before plantar
incision and remifentanil infusion) and group KN93 (intrathecal injection of KN93 (50µg/20µl,
dissolved in 10%DMSO) 30 min before plantar incision and remifentanil infusion). The paw withdrawal
mechanical threshold (PWMT) and the paw withdrawal thermal latency (PWTL) were tested at 24 h
before and 2h, 6h, 24h, 48 h after surgery.
Results: Compared with that of group C, PWTL ((11.24±0.69)s, (10.36±0.29)s, (11.29±1.12)s,
(12.21±0.75)s) and PWMT ((25.5±1.20)g, (24.92±1.98)g, (25.47±1.54)g, (27.14±1.04)g) of group I
were significantly decreased at 2h, 6h, 24h, 48 h after surgery (P< 0.05). Compared with that of group
I, PWTL ((8.48±0.72)s, (8.58±0.45)s, (8.46±0.92)s, (9.07±0.79)s) and PWMT ((21.2±2.42)g,
(19.58±1.12)g, (21.87±1.56)g, (22.26±1.64)g) of group R were significantly decreased after surgery
(P< 0.05). Compared with that of group R, PWTL ((13.32±0.73)s, (11.79±0.32)s, (11.86±0.98)s,
(12.76±0.82)s) and PWMT ((29.75±1.38)g, (28.27±1.16)g, (26.5±1.02)g, (27.79±1.22)g) of group
KN93 were significantly increased at the corresponding time points (P< 0.05). In addition, there was
no significant difference in PWTL and PWMT between group DMSO and group R.
Discussion: Intrathecal injection of CaMKⅡ inhibitor KN93 could relieve the postoperative
hyperalgesia induced by remifentanil in rats.
References:
1. Gu X, Wu X, Liu Y, Cui S, Ma Z. Tyrosine phosphorylation of the N-Methyl-D-Aspartate receptor 2B
subunit in spinal cord contributes to remifentanil-induced postoperative hyperalgesia: the preventive
effect of ketamine. Molecular Pain. 2009;5:76.
2. Katano T, Nakazawa T, Nakatsuka T, Watanabe M, Yamamoto T, Ito S. Involvement of spinal
phosphoryLation cascade of Tyr1472-NR2B, Thr286-CaMKⅡ, and Ser83l-GluRl in neuropathic pain.
Neuropharmacology. 2011;60(4):609-16.
Funding: This research was supported by National Natural Science foundation of China Grant no.
81171047.
A04
THE INFLUENCE OF SMOKING ON THE POSTOPERATIVE OPIOID REQUIREMENTS OF
PATIENTS UNDERGOING ROUTINE CESAREAN SECTION
T.L. Hunt II, B. Hoelzer, T. Weingarten
Divsion of Pain Medicine, Mayo Clinic, Rochester, MN, USA
Introduction: Nicotine has long been known to have analgesic properties in both human and animal
experimental pain models. Furthermore in some studies, nicotine administration in nonsmokers has
been shown to have an analgesic effect on post-surgical pain. Paradoxically, tobacco use is
associated with greater pain intensity and functional impairment in chronic pain disorders. There are
several reports in the literature that report that smokers have greater post-operative pain and opioid
requirements than nonsmokers. This case series investigates this relationship in healthy parturients
who are undergoing routine cesarean section.
Materials and methods: We conducted a retrospective chart review of 58 patients that underwent
routine caesarean section with spinal anesthesia at Mayo Clinic. An in depth review of the subjects'
medical, surgical and anesthetic records ware performed which resulted in six patients who met the
stringent inclusion criteria. Primary end-point was total daily oral morphine equivalents forty-eight
hours after surgery. Secondary endpoints included nausea, pruritus, pain scores, and hospital days.
Results: There was a greater than four-fold increase in opioid requirements by total dose and dose /
weight over forty-eight hours in the patients identified as smokers. Their pain scores were relatively
higher in the smoking group despite increased opioid consumption.
Discussion: Nicotine may contribute to increased opioid requirements in healthy parturients
undergoing routine cesarean section. A larger study should be considered to further investigate this
potential relationship.
References:
Flood, P. Intranasal Nicotine for Postoperative Pain Treatment. Anesthesiology. December 2004 Volume 101 - Issue 6 - pp 1417-1421
Habib AS. Transdermal nicotine for analgesia after radical retropubic prostatectomy. Anesth Analg.
2008 Sep;107(3):999-1004.
Hong D. Transdermal nicotine patch for postoperative pain management: a pilot dose-ranging study.
Anesthesia & Analgesia, 2008
Vogt MT. Influence of smoking on the health status of spinal patients: The National Spine Network
Database. Spine 2002; 27:313-319.
Weingarten TN. Impact of tobacco use in patients presenting to a multidisciplinary out- patient
treatment program for fibro- myalgia. Clinical Journal of Pain 2008
Weingarten TN. An Assessment of the Association Between Smoking Status, Pain Intensity, and
Functional Interference in Patients with Chronic Pain. Pain Physician 2008; 11:643-653
Yunus MB. Relationship between fibromyalgia features and smoking. Scandinavian Journal of
Rheumatology 2002; 31:301-305
Creekmore F. Postoperative Opiate Analgesia Requirements of Smokers and Nonsmokers. Ann
Pharmacother June 2004 vol. 38 no. 6 949-953
Olson LC. A Transdermal Nicotine Patch Is Not Effective for Postoperative Pain Management in
Smokers: A Pilot Dose-Ranging Study. A & A December 2009 vol. 109 no. 6 1987-1991.
Personal conflicts of interest disclosure: Each author warrants that there are no commercial
associations that might pose a conflict of interest in connection with the submitted article.
A05
VARIABLES IMPACTING THE EFFICACY OF REGIONAL NERVE BLOCK FOR POSTOPERATIVE PAIN MANAGEMENT IN TOTAL KNEE ARTHROPLASTY (TKA) PATIENTS: A
RETROSPECTIVE STUDY
Q. Liu, J.E. Chelly, M.S. Gold
University of Pittsburgh Medical Center, Pittsburgh, PA, USA
Introduction: Continuous nerve blocks have been demonstrated to provide more effective
perioperative pain control than PCA opioid in orthopedics (Richman et al., 2006; McFarlane et al.,
2009) However, protocols of local anesthetic administration do not account for the possibility that
pathological conditions may influence the expression, distribution, and/or biophysical properties of
sodium channels (Amir et al., 2006), and therefore LA requirement. To begin to explore this
possibility, we performed a retrospective study of patients undergoing TKA at a hospital with a wellestablished protocol for post-operative analgesia to assess the impact of pre-existing conditions on
LA usage.
Materials and methods: Data were extracted from electronic medical records of patients who
underwent unilateral primary total knee replacement (TKA) and TKA revision (TKA-R) performed at
UPMC Shadyside hospital over a period of 18 months. The post-operative analgesia protocol was
based on a combination of narcotics delivered via PCA, supplemented with PO narcotics, and
regional anesthesia achieved with continuous femoral (0.0625% bupivacaine, 5 ml/h) and sciatic
(0.03% bupivacaine, 3 ml/h) infusions that could be supplemented to a max of 3 ml/h. Resting pain
was estimated from the average VAS score, while pain with activity was estimated from the VAS
associated with physical therapy. Cumulative narcotic and LA use was determined. A priori
hypotheses were tested with one- and two-way ANOVAs with post-hoc analysis as appropriate.
Results: While pain scores and narcotic use were comparable in TKA (n = 994) and TKA-R (n = 232)
patients, LA use was significantly higher TKA-R patients, particularly on post-operative day 1 (POD1).
Pain scores were higher, and LA use was higher (close to the theoretical maximum) in patients (n = 7)
undergoing TKA-R because of infection than either TKA or the remaining TKA-R patients on POD1.
Comparable results were obtained when data were analyzed as a function of the presence of
diabetes and/or diabetes with polyneuropathy (DPN), with LA use elevated in DPN patients
undergoing TKA (n = 19) and TKA-R (n = 5), with the latter again close to the theoretical maximum.
LA was also elevated in diabetic patients without complications (n = 67) undergoing TKA-R compared
to their non-diabetic counterparts. There was no significant influence of obesity (BMI > 31) on pain,
narcotic or LA use. Nor was there a detectable influence of surgeon, age or sex on these variables.
Discussion: Our results suggest that there are subpopulations of patients, such as those undergoing
TKA-R, who require more LA to achieve comparable levels of post-operative pain control. Additional
subpopulations, such as those undergoing TKA-R for infection may be resistant to LA, and therefore
may require alternative post-operative pain management strategies. Furthermore, there are
subpopulations of patients such as those with diabetic neuropathy where there is not only an apparent
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loss of LA efficacy, but who may also be more susceptible to LA-induced toxicity. This combination
would constitute a patient subpopulation in which LA based peripheral nerve blocks are
contraindicated. Ongoing work is focused on the identification of mechanisms underlying these
apparent changes in LA efficacy.
A06
THE THERAPEUTIC EFFECT OF REPEATED INTRATHECAL INJECTION OF IFENPRODIL ON
BONE CANCER PAIN IN MICE
Z. Ma, X. Gu, X. Yang, W. Zhang, Y. Liu
Department of Anaesthesiology, Affiliated Drum Tower Hospital, Medical School of Nanjing University,
Nanjing, China
Introduction: NR2B-contaning NMDA receptors play an important role in spinal dorsal horn
nociceptive processing. Single intrathecal injection of ifenprodil, the most promising NR2B subunitspecific antagonist can reduce the pain in a mouse model of bone cancer pain. But the antihyperalgesic efficacy achieved maximum at 2 h after intrathecal administration of ifenprodil and
1
disappeared at 24 h . So the aim of the present study was to evaluate the effects of repeated injection
of ifenprodil on bone cancer pain and the expression of NR2B protein in L3-L5 lumbar spinal cord
segments in the mouse model.
Material and methods: All experiments were approved by the Animal Care and Use Committee at
the Medical School of Nanjing University. 96 male C3H/HeJ mice were divided randomly into tumor
group (Group T), control group (Group C) and sham group (Group S). Osteosarcoma NCTC 2472
cells were implanted into the intramedullary space of the right femurs of mice in group T and C to
induce ongoing bone cancer pain. Mice in group S were inoculated by α-MEM without cells. On 14d
after inoculation, Group T were treated by intrathecal injection of ifenprodil 10µg (dissolved in 5µl 20%
DMSO) once daily for three consecutive days. Group C and Group S were treated by intrathecal
injection of 5ul 20%DMSO at the same time points. Pain behaviors such as the spontaneous lifting
and the paw withdrawal mechanical threshold(PWMT) were observed on 1d before inoculation and on
3d, 5d, 7d, 10d, 14d, 17d, 19d, 23d after inoculation. Lumbar intumescentia of mice in each group
was taken out to investigate the expression level of NR2B after pain behaviors tests at the
corresponding time points.
Results: On 14d after operation, the number of spontaneous flinches (12.33±1.98) was increased
and PWMT (1.1±0.65)g was decreased in group T compared with group S (P< 0. 05). Consistent with
the changes of pain behaviors, results of western blot showed that the expression of NR2B in L3-L5
lumbar spinal cord segments was increased significantly on 14d in group T (1.38±0.09) compared
with group S (P< 0. 05). On 17d, 19d and 23d after operation, compared with the basal level of day14
before administration and group C, the number of spontaneous flinches ((6.38±1.41), (6.50±1.20),
(7.63±1.07)) of group T were decreased, PWMT ((0.95±0.26)g, (1.00±0.30)g, (1.05±0.26)g) were
increased, and the expression of NR2B ((1.17±0.03), (1.15±0.04), (1.15±0.05)) were decreased (P<
0.05).
Discussion: Repeated intratheal injection of ifenprodil attenuated pain related behaviors and reduced
the expression of NR2B in lumbar intumescentia in the mouse model of bone cancer pain.
References: 1. Gu X, Zhang J, Ma Z, Wang J, Zhou X, Jin Y, Xia X, Gao Q, Mei F. The role of Nmethyl-D-aspartate receptor subunit NR2B in spinal cord in cancer pain. Eur J Pain 2010;14:496-502.
Funding: This research was supported by National Natural Science foundation of China Grant no.
81070892 and 81171048.
A07
EFFECTS OF INTRATHECAL INJECTION OF THE SMALL PEPTIDE INHIBITOR OF MLIN10PDZ1 DOMAIN ON THE BEHAVIORS OF BONE CANCER PAIN IN MICE
Z. Ma, X. Gu, Y. Zhou, K. Ni, Y. Liu
Department of Anaesthesiology, Affiliated Drum Tower Hospital, Medical School of Nanjing University,
Nanjing, China
Introduction: The mLin-10 also named Mint1/X11, which belongs to the X11 family, is involved in the
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transportation of proteins and neurotransmitters in neurons . Prelimilary studies have shown that
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NR2B subunit plays an important role in the cancer pain . Vesicles containing NR2B subunit are
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transported along microtubules by KIF17, a neuron-specific molecular motor in neuronal dendrites .
Selective transport of NR2B is accomplished by direct interaction of the KIF17 tail with a PDZ domain
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of mLin-10 . In this study, we used a synthetic peptide combining specifically with the mLin10-PDZ1
domain and inhibiting the interaction between KIF17 and mLin10, to investigate the role of the
mLin10-PDZ1 domain in bone cancer pain .
Material and methods: All experiments were approved by the Animal Care and Use Committee at
the Medical School of Nanjing University. 40 male C3H/HeJ mice were randomly divided into five
groups (n=8): group T, group G1, G2, G3 and group S. Osteosarcoma NCTC 2472 cells were
implanted into the intramedullary space of the right femurs of mice in group T and G1-G3. Mice in
group S were inoculated by α-MEM without cells. On day14 after inoculation, mice in group G1-3 were
intrathecally injected of the small peptide inhibitor of mLin10-PDZ1 domain 2.5µg/5µl, 5µg/5µl,
10µg/5µl, respectively. Group S and T were intrathecally injected of 5µl 10%DMSO. Pain behaviors
including the spontaneous flinches and the paw withdrawal mechanical threshold (PWMT) were
observed.
Results: Compared with group S, the number of spontaneous lifting (13.46±1.44) was increased and
PWMT (1.83±0.23g) was decreased on day14 after inoculation in group T and G1-3 (P< 0.05). The
number of spontaneous lifting was decreased, and PWMT was increased after intrathecal injection in
group G1-3 compared with the base level on day14 and group T at the same time points (P< 0.05).
The analgesic effects of group G3 was more conspicuous than group G1 and G2 (P< 0.05).
Discussion: Intrathecal injection the small peptide inhibitor of mLin10-PDZ1 domain can efficiently
relieve the bone cancer pain in mice.
References:
1. Rogelj B, Mitchell JC, Miller CC et al. The X11/Mint family of adaptor proteins. Brain Res Rev
2006;52(2):305-15.
2. Gu X, Zhang J, Ma Z et al. The role of N-methyl-D-aspartate receptor subunit NR2B in spinal cord
in cancer pain. Eur J Pain 2010;14:496-502.
3. Guillaud L, Setou M, Hirokawa N. KIF17 dynamics and regulation of NR2B trafficking in
hippocampal neurons. J Neurosci 2003;23(1):131-40.
4. Setou M, Nakagawa T, Seog DH et al. Kinesin superfamily motor protein KIF17 and mLin-10 in
NMDA receptor-containing vesicle transport. Science 2000;288(5472):1796-802.
Funding: This research was supported by National Natural Science foundation of China Grant no.
81171048.
A08
ROLE OF MIRS IN THE DEVELOPMENT OF SUSTAINED NEUROPATHIC PAIN FOLLOWING A
PERIPHERAL NERVE INJURY
M. Norcini, A. Sideris, L.A. Martin Hernandez, T.J.J. Blanck, E. Recio-Pinto
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Anesthesiology, Anesthesiology, Physiology and Neuroscience, Anesthesiology , Pharmacology,
NYU Langone Medical Center, New York, NY, USA
Introduction: Chronic neuropathic pain following surgery is often associated with peripheral nerve
injury. Unfortunately, adequate control of acute pain does not always lead to a decrease in the
occurrence of chronic neuropathic pain. Peripheral nerve injury alters the expression of hundreds of
proteins in the dorsal root ganglia (DRG). Many of these proteins have been found to contribute to the
injury-induced development of chronic neuropathic pain. Targeting some of these proteins has led to
successful treatments for acute pain, but not for preventing or treating sustained postoperative
neuropathic pain. Treatment of chronic neuropathic pain may require the alteration of multiple
proteins. Since a single miR can affect the expression of many proteins, we have attempted to identify
miRs that could be used as targets for preventing the development of sustained postoperative
neuropathic pain.
Materials and methods: Adult rats undergoing sciatic nerve tibial- or sural-spared nerve injuries
(Tibial-SNI, Sural-SNI) were used. The time course of mechanical (Von Frey) and cold allodynia
(acetone test) was measured over a 3 month period. Total RNA isolated from individual L4- and L5DRG was used for miR microarrays analysis. TargetScan and Miranda software was used to identify
potential mRNA targets. The list of potential mRNA targets was limited to those encoding for ion
channels, neurotransmitter receptors and other proteins known to be important for normal neuronal
excitability.
Results: To increase the probability of detecting pain-specific deregulated miRs, we compared the
animal behavior and the DRG miR pattern of Sural- and Tibial-SNI animals. The two SNI variants
initially displayed strong mechanical allodynia, but behavioral discrepancies emerged: Sural-SNI
animals maintained strong mechanical and cold allodynia, while Tibial-SNI animals recovered from
mechanical allodynia and never developed cold allodynia. We found that the levels of most of the
detected miRs (>180) in L4- and L5-DRG were altered following either SNI variant; however, only 8
miRs were uniquely altered in one of the SNIs or in the opposite direction in both SNIs. The targets of
these 8 miRs include mRNAs encoding for various ion channels including pacemakers, voltagedependent sodium, calcium and potassium channels.
Discussion: The expression of most of the miRs in DRG are affected following either peripheral
nerve injury variant. However, only 8 miRs were differentially modulated between the two SNI injuries.
Based on their identified and predicted mRNA targets, a decrease in the expression of any of 4 of the
identified miRs may lead to an increase in neuronal excitability in Sural-SNI DRG neurons; while an
increase in the expression of any of 7of the indentified miRs may lead to a decrease in neuronal
excitability in Tibial-SNI DRG neurons. The predicted miR-mediated increase in neuronal excitability
correlates with the development of sustained neuropathic pain in Sural-SNI; while the predicted miRmediated decrease in neuronal excitability correlates with the recovery from early neuropathic pain in
Tibial-SNI. Additional studies are being done to investigate whether alteration of the expression of any
of the identified miRs in vivo can be used to prevent or treat sustained postoperative neuropathic
pain.
A09
DOES SUTURING IMPROVE THE RATE OF SUCCESSFUL REACTIVATION OF LABOR
EPIDURAL CATHETERS FOR POSTPARTUM TUBAL LIGATION (PPTL) SURGERY
S. Shah, S. Cohen, A. Mohiuddin, M. Fernandez, C. Kloepping, P. Shapiro, S. Mungekar, C.W.
Hunter
Anesthesiology, Robert Wood Johnson University Hospital-UMDNJ, New Brunswick, NJ, USA
Introduction: Ninety two percent of lumbar epidural catheters for labor pain remained in place until
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the time of PPTL Surgery can be reactivated successfully until 24hrs after they have been placed .
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Suturing the epidural catheter in our previous study , reduced catheter movement, the need for re
insertion, the incidence of one sided anesthesia and epidural vessel puncture and provided a high
success rate of epidural blocks.
Methods: Following IRB approval and informed consent, we studied 121 ASA I-II patients scheduled
for PPTL with epidural catheter in place. Of 2400 parturients who received epidural analgesia for labor
pain and were randomized into 1200 patients who had the epidural sutured and 1200 that had
catheter without suture, two groups were identified. Group I (N=48) had their catheters sutured upon
insertion. Group II (N=73) had their catheters secured without suture. The epidural space was located
at L2,3 using LOR to air technique and a midline approach with the patient in lateral or sitting flexed
position. An 18g “B Braun” ( B.Braun Medical Inc., Bethlehem PA18018) closed end tip catheter was
directed 5 cm cephaled. For Group I parturients, the cathters were sutured with 3-0 vicryl suture at the
insertion site and then looped downward 5 cm. Group II parturients had their epidural catheters
looped downward 5 cm without being sutured. Mastisol glue and transparent dressing were then
applied. An investigator recorded the patient's age, height, weight, parity, position for insertion of
catheter, distance of epidural space from skin and previous history of epidural block , spinal block,
spinal tap, dural puncture or blood patch. Also recorded were incidence of failed epidural block (a
properly functioning epidural block which subsequently failed) catheter dislodgment, blood vessel
puncture, dural puncture, need for catheter readjustment or reinsertion, occurrence of unilateral block,
maximum lumbar sensory level, Bromage Score (1=complete motor block, 5=no weakness of hip
flexion) catheter position and length of catether coiled under the skin at the time of catheter removal,
and overall satisfaction (0 = worst, 10=best).
Results: Groups did not differ in age, weight, height, parity, distance of epidural space from the skin,
position, history of previous neuraxial procedure, Bromage Score, maximum sensory level. Overall
satisfaction was high in both groups, 9.6+0.9 vs.. 9.5+1.0 for Groups I and II respectively. The length
of catheter coiled under skin upon removal was 0.5+0.7cm and 0.2+0.6cm ( p < 0.05 Student's
unpaired test). The incidence of catheter movements and resulting complications and corrections are
shown in Tables I & II respectively. Of the 12 failed blocks in group II, 3 occurred within 4 to 12
hours(4%), 7 within 12 to 24 hours(10%) and 2 after 24 hours(3%).
Catheter
Movement
Outward
Catheter
Movement Inward
Catheter coiled
Subcut
Dislodged
Group I
7(14%)
4(8%)
0.5 ± 0.7
0
Group II
26(36%)
13(18%)
0.2 ± 0.6
11(15%)
[Table I]
Failed Block
One-sided
Anesthesia
Blood Vessel
Puncture
Readjustment
of Catheter
Reinsertion of
Catheter
Catheter Kink
Group I
0
0
0
2(4%)
0
1(2%)
Group II
12(16%)*
5(7%)
1(1%)
4(5%)
0
1(1%)
[Table II: Incidence of Complications and Correctio]
Conclusion: Suturing the epidural catheter for labor pain increased the success rate of reactivation of
epidural block for PPTL, reduced catheter movement and need for reinsertion, decreased the
incidence of one-sided anesthesia and catheter puncture of epidural vessels.
References:
1. Goodman EJ et al. Reg Anesth 23: 258 - 261, 1998
2. Cohen S et al. Anesthesiology 89: A1065, 1998
A10
PROPHYLAXIS VERSUS THERAPEUTIC BLOOD PATCH FOR ACCIDENTAL DURAL
PUNCTURE IN OBSTETRIC PATIENTS
1
1
2
1
1
1
1
S. Shah , S. Cohen , I.P. Lowenwirt , R. Chhokra , A. Mohiuddin , K. Dauphinee , S. Yeh , T.
1
1
Shkolnikova , C.W. Hunter
1
Anesthesiology, Robert Wood Johnson University Hospital-UMDNJ, New Brunswick, NJ,
Anesthesiology, New York Hospital, Queens, NY, USA
2
Introduction: Therapeutic epidural blood patch (TEBP) is a standard of care of treatment of postdural
puncture headache (PDPH). Prophylactic epidural blood patch (PEBP) has been recommended for
accidental dural puncture in order to eliminate or reduce the incidence of PDPH and more serious
complications of dural puncture: hearing loss, diplopia and tinnitus. However, this treatment is not
commonly accepted.
Objective: In this prospective randomized study we compared the efficacy of a PEBP with TEBP in
preventing PDPH and its complication in obstetric patients.
Method: Following IRB approval, obstetric patients with accidental dural puncture from 16g or 17g
needles were randomized and allocated to two treatment groups.
Group I (n=54 PEBP Group) patients received 15-20 autologous blood through the indwelling epidural
catheter at least 5 hours following the last dose of local anesthetic for labor cesarean delivery then the
epidural catheter was removed.
Group II: ( n = 54 TEBP ) did not receive blood through the catheter. These patients were managed
conservatively with IV hydration, bed rest, theophylline or caffeine. When PDPH and/or its
complications developed, a TEBP was performed at patients request with 15-20 ml autologous blood
via an epidural needle.
An independent investigator evaluated all patients at 12-hour intervals, prior to discharge and then by
phone for one week. Patients were instructed to contact the anesthesiology department if they
developed PDPH or its complications at any time later. Headache (HA) was rated on a scale of 0-3
(0=no HA, 3=severe HA). Treatment failure was defined as HA scale of 3 following EBP in either
group which required a second EBP.
Results: Groups did not differ in age, height, weight or parity. PEBP was successful in 80% (n=43) of
patients (Table I) and only 6 (11%) patients required a second BP while 26% (n=14) of TEBP were
asymptomatic following conservative treatment and did not require EBP. Furthermore, of the control
TEBP Group, 3 patients (5.6%) developed diplopia, and 5 patients (9%) required a second blood
patch. 5 patients (9%) from Group I vs. 10 patients (18.5%) from Group II required emergency room
visit for severe HA after discharge. No patient in either group developed complications from EBP.
Duration of hospital stay was 3.4+1.5 & 3.0+1.3 days for Group I & II respectively. Prophylactic blood
patch is a simple and safe technique associated with a good success rate (80%) in preventing PDPH
and its complications with less patients suffering and with reduced morbidity after accidental dural
puncture.
[Table I: Complications from Dural Puncture]
Conclusions: Prophylactic blood patch is a simple and safe technique associated with a good
success rate (80%) in preventing PDPH and its complications with less patients suffering and with
reduced morbidity after accidental dural puncture.
Reference: 1. Anesth Analg 1989; 69:522-3.
A11
RATS WITH FEATURES OF METABOLIC SYNDROME EXHIBIT SEX-SPECIFIC DIFFERENCES
IN NOCICEPTION
1
2
1
1
1
1
2
M. Sternberg , A. Mirra , N. Cheng , C.J. Watson , L. Koch , S. Britton , G. Vesce , R. Lydic
1
1
2
Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA, Department of Clinical
Veterinary Science, Università degli Studi di Napoli Federico II, Naples, Italy
Introduction: Pain processing is polygenically modulated and varies as a function of sex, body
habitus, modality, and genotype. Human pain has been positively correlated with obesity (J Pain 8:
430, 2007) and both pain processing and self-reports of pain vary between men and women (J Pain
13: 228, 2012; J Pain 101: 259, 2003). Rats selectively bred to have features of metabolic syndrome
(Science 307: 418, 2005) may provide an animal model that can help elucidate the underlying
neurochemical mechanisms contributing to differences in pain that are sex-specific and associated
with obesity/metabolic syndrome (Anesthesiology 113: 1176, 2010). As an initial step prior to
pharmacological studies of chronic pain, this experiment is testing the hypothesis that rats with
features of metabolic syndrome exhibit sex-specific differences in nociception.
Materials and methods: To date we have used multimodal pain testing to evaluate nociceptive
responses in male (n = 3) and female (n = 3) rats with features of metabolic syndrome. The
experiments quantified hind paw withdrawal latency to a heat stimulus using the Hargreaves method
(Pain 32: 77, 1988). Gram-equivalent responses to mechanical stimuli were quantified using the updown method (J Neurosci Methods 53: 55, 1994). Duration of response to the acetone spray test was
used to characterize the response to a cold thermal stimulus (Anesth Analg 101: 457, 2005).
Results: Responses were quantified (mean ± SD) for male and female rats on each of the three pain
modalities tested. Paw withdrawal latencies (PWL) in seconds for females (7.26 ± 1.45) and males
(5.98 ± 1.51) differed by 21.4%. Responses to mechanical stimuli (in grams) for females (8.66 ± 6.35)
and males (5.40 ± 5.21) differed by 60.4%. Duration of response to the acetone spray test in seconds
for females (0.5 ± 0) and males (0.67 ± 0.26) differed by 33.3%.
Discussion: Previous studies found that lean rats selectively bred for enhanced aerobic fitness had
higher thresholds for heat nociception than did rats bred to promote features of metabolic syndrome
(Neurosci Lett 443: 37, 2008). Lean/fit rats also recover more rapidly from neuropathic pain caused by
chronic constriction injury of the sciatic nerve (Anesthesiology 113: 1176, 2010). The present results
indicate that in obese rats with features of metabolic syndrome the females had a longer PWL, a
greater threshold for mechanical nociception, and a longer duration of response to the acetone test.
These data imply a lower pain threshold in the obese, male rats. The preliminary results also suggest
that rats selectively bred to enhance the polygenic modulation of obesity/metabolic syndrome offer a
unique resource for studies aiming to elucidate mechanisms contributing to sex-specific differences in
nociceptive processing.
A12
THORACIC EPIDURAL ANALGESIA FOR POSTOPERATIVE PAIN MANAGEMENT AFTER
PECTUS EXCAVATUM AND PECTUS CARINATUM REPAIR
S. Turial, V. Kelsch, F. Schier
Pediatric Surgery, University Medical Center Mainz, Mainz, Germany
Purpose: The aim of the present retrospective study was to investigate the efficacy and safety of the
thoracic epidural analgesia (TEA) for the pain control after surgical correction of chest wall deformities
in adolescents. A comparison of the results to a historical group of patient-controlled analgesia (PCA)
after identical surgical procedures is provided.
Methods: Patients treated for pectus excavatum or carinatum (Nuss or Ravitch procedures) in the
last three years at our institution were randomly assigned to receive TEA for postoperative pain
control. Demographic and clinical data (body weight, age, sex, Haller index, operative time and
course), pain related data and complications (the incidence of catheter-related complications or
adverse events of treatment such as nausea, vomiting, and respiratory depression) were collected
prospectively. Pain was assessed every 4 to 8 hours on a visual analog scale by the nurses based on
a standardized regime. Daily use of analgesics was also recorded for the total time of hospital stay.
For the purposes of the present study, a retrospective data analyze was performed and the results
were compared to a historical cohort of patients which received patient-controlled analgesia (PCA)
after the same kind of surgeries.
Results: During the study period 22 patients (average age: 17.3years, 14 male, 8 female, 15 Nussprocedures, 7 Ravitch-procedures) received TEA. The epidural catheter could not be placed in three
patients and was removed within 24 hours in 2 patients. No serious complications related to the
catheter placement were noted. On average the PCA devices were maintained for 5.3 days and TEA
for 4.7 days, respectively. Serious attacks of vomiting and nausea were noted in 64 % in PCA group
and in 30 % of TEA group. Respiratory depression symptoms occurred in 42 % of the PCA group and
in 10 % of the TEA group, respectively. The patients in TEA group were mobilized 1.5 days after
surgery on average. In contrast the patients with CPA were mobilized, on average, after 4.5 days
postoperatively.
Conclusion: Both the TEA and the PCA provide effective postoperative pain relief after surgical
repair of chest wall deformities. PCA caused severe side effects in the majority of patients in
comparison to the TEA. In addition, the TEA enables an early patient mobilization and provides high
level on patient comfort.
A13
FLUOROSCOPIC GUIDANCE DECREASES THE MECHANICAL FAILURE RATE OF THORACIC
EPIDURAL CATHETERS USED FOR POSTOPERATIVE PAIN CONTROL
K. Washburn, M. Yeager, P. Barr, A.K. Bonham, R. Loftus, M. Parra
Anesthesiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
Introduction: Postoperative thoracic epidural analgesia is a common and effective technique for
control of post-thoracotomy pain. However, blind placement of thoracic epidural catheters has a
substantial failure rate (1,2). Routine use of flouroscopic guidance to place thoracic epidural catheters
is a relatively new approach with unproven efficacy.
Materials and methods: With IRB approval and following written informed consent, we randomized
patients scheduled for open thoracotomy to have an epidural catheter placed before surgery for
postoperative analgesia with either; a) fluoroscopic guidance (F) or b) via a traditional (T) ´blind´
technique (no fluoroscopy). In the experimental group F, the epidural space was entered at the T6T10 level using loss of resistance (LOR). An epidural catheter was then threaded under fluoroscopic
guidance to place the tip of the catheter at the body of T4. Following injection of a test dose of local
anesthetic, an epidurogram was obtained using 5ml dye to confirm epidural placement. In the control
group T, the T6 vertebral level was identified using anatomic landmarks and the epidural space
identified using LOR. An epidural catheter was then inserted 5cm after which a test dose of local
anesthetic was injected. Patients in both groups then received a continuous infusion of 1/8%
bupivacaine at 4 ml/hr. Patients in both groups were followed and managed postoperatively by an
Acute Pain Service team of doctors and specialty nurses who followed a pre-identified catheter use
algorithm.
Results: 45 patients were randomized (23 F, 22 T). In Group T, the average duration of catheter use
was 62.3 (+/- 24 S.D.) hours which was not different from Group F, where the average duration of
catheter use was 67.4 (+/- 29 S.D.) hours. In Group T 5 of 22 catheters (23%) were removed due to
mechanical loss of function (leakage, dislodgement) while 0/23 catheters in Group F had mechanical
failure.
Discussion: Previous prospective studies of epidural catheters in place for postoperative pain control
have reported failure rates similar to the Group T failure rate of 23% due to mechanical loss of
function (1,2). In this analysis, we did not find that the average duration of epidural catheter use after
surgery was significantly affected when catheters were placed under fluoroscopic guidance. Many
factors other than catheter function affect duration of catheter use including duration of chest tube
placement, extent of surgery, bleeding, etc. We did, however, find that the mechanical failure rate that
has been reported by other groups (13 to 24% [1-3]) appeared to be improved probably due to
confirmation of epidural location and greater insertion depth of catheters when they are placed under
direct X-ray guidance.
References:
1. Anesth Analg. 2006 Oct;103(4):1026-32.)
2. Anaesth Intensive Care. 1998 Apr;26(2):165-72.
3. Anaesthesia. 2001 Jan;56(1):75-81.
No authors report a financial conflict of interest.
A14
E-LEARNING, A 3D LEARNING MODULE OF THE BRACHIAL PLEXUS DEPICTING ANATOMY
RELEVANT TO REGIONAL ANESTHESIA CAN BE AN EFFECTIVE EDUCATIONAL RESOURCE
K.P. Armstrong, J. Turgeon, T.D. Wilson
1
2
Department of Anesthesia and Perioperative Medicine, Anatomy and Cell Biology, CRIPT Lab,
Western University, London, ON, Canada
Introduction: Digital learning resources have increased in number and manner of access (1,2) for
almost all allied health fields. These resources may improve the understanding of specific anatomy
(2). In some instances, simple digital models may be adequate. However, anatomically, functionally,
and spatially complex models may represent one area where 3D visualization may be more
appropriate in other situations. We hypothesize that 3D digital learning resources of the BP can
improve anatomical understanding and knowledge for learners.
Material and methods: A 3D BP digital model was developed using the Visible Human Dataset and
digital segmentation techniques (3). Anatomical data related to regional anesthesia was presented as
interactive online modules (figure 1). The modules were designed in guided (G) and self guided (S)
formats (3). Points of emphasis included structure, neural contribution, spatial relationships,
potentially vital structures, etc. Participants included allied health students and anesthesia residents.
All participants completed an anatomical pretest enabling classification of high (H) or low (L)
“knowledge groups”. Using identical learning objectives, participants were assigned to one of 4
groups HS, HG, LS, LG. Following completion of the module, a post-test was administered. Subjects
completed evaluations of the model and provided feedback on their experience. Descriptive statistics
and one-way analysis of variance (ANOVA) were used to compare pre-test scores, post test scores,
and the relationship of prior knowledge and information acquisition. Likert responses for subjective
evaluations were grouped as generally negative (disagreed and strongly disagreed), or positive
(agreed and strongly agreed) scores.
Results: Exposure to the model led to improved post test when compared to the pre-test scores
(figure 2). Low knowledge individuals when exposed to guided version of the learning module where
found to have the greatest improvement . Subjective evaluations were supportive of this learning tool
(table 2).
Discussion: Pre- and post exposure testing suggest that this model is effective for learning BP
anatomy relevant to regional anesthesia at all levels of expertise, significantly so in HG, LS, LG
learning groups. The novice learners may benefit most from a guided format. Further work to evaluate
learning strategies of virtual learning environments is required.
[Figure 1. Brachial plexus module images]
[Figure 2. Mean score pre and post test scores ± SD]
Treatment
Paths
Feedback
Survey
Statements
HS (n=12)
HG (n=11)
LS (n=8)
LG (n=7)
response
-
+
-
+
-
+
-
+
S9. I found
this module
was an
effective
way to
learn
0
100
0
100
0
100
0
71
S10.
Overall this
model
contributes
to my
knowledge
of the
brachial
plexus
0
92
0
100
0
100
14
86
S11. Prior
to this
module I
was
comfortable
with my
knowledge
of the
brachial
plexus
33
42
18
45
50
13
71
14
S12. This
module
was
applicable
to my
course or
field of
study
0
92
0
100
0
0
86
100
[Table 2. Responses provided by participants]
References:
1. Drake et al. Medical education in the anatomical sciences:. Anatomical Sciences Education
2009; 2(6):253-259
2. Khalil et al. Using computer‐based interactive imagery strategies for designing instructional
anatomy programs. Clin Anat 2005;18(1):68-76
3. Turgeon et , User experience and its influence on the evaluation of information presentation in
an online learning module. American Association of Anatomists, San Diego CA. April 2012.
Funding: Department of Anatomy and Cell Biology
A15
SUPPLEMENTARY ULNAR NERVE BLOCKADE EXTENDS ANALGESIA IN PATIENTS
RECEIVING SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK FOR ULNAR DISTRIBUTION
HAND SURGERY
J.P. Cameron, B.C.H. Tsui, J.C. Leung, Edmonton Academy of Regional Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Hand surgery in our institution is most commonly performed under regional anesthesia.
1
Post-operative pain is a common occurrence after this type of surgery. Previous studies have shown
improved intra-operative anesthesia and post-operative analgesia in patients undergoing proximal
2,3
brachial plexus blockade plus multiple terminal nerve blocks.
This study examined whether
prolonged analgesia was achieved after supraclavicular brachial plexus blockade plus a
supplementary ulnar nerve block versus supraclavicular block alone for patients undergoing hand
surgery in the ulnar distribution.
Material and methods: After institutional ethics approval, adult elective day-surgery patients
undergoing surgery on the fourth and/or fifth metacarpals and/or phalanges were recruited to the
study. Patients randomized to the control group received a standard ultrasound-guided
supraclavicular block using 25-30 mL of 1.5% lidocaine + 0.125% bupivacaine. Patients in the study
group received a reduced-volume ultrasound-guided supraclavicular block of 20 mL 1.5% lidocaine +
0.125% bupivacaine plus an ulnar nerve block using 5 mL of a 0.5% ropivacaine + 0.125%
bupivacaine solution. Block performance time was recorded, and patients were contacted the
following day to assess the onset of sensation and movement in the affected limb as well as
maximum numerical rating scale pain score.
Results: Twenty-five patients were recruited to the study; five were lost to follow up, leaving ten in
each group. On average, total time to perform the block(s) was longer for the combined block patients
than the supraclavicular-only patients (13.3 ± 7.5 min vs. 10.7 ± 4.8 min), but not significantly so
(p=0.36). Patients who received a combined block experienced later onset of pain compared to the
control group (525.8 ± 238.9 min vs. 296.3 ± 61.3 min; p=0.014). Time to maximal pain sensation was
also longer in the combined block group (621.8 ± 282.7 min vs. 363.8 ± 82.9 min; p=0.019). The
average pain intensity after recovery of sensation was similar between the two groups (6/10 study
group vs 6.6/10 control group).
Discussion: Administering a supplementary ulnar nerve block in addition to a supraclavicular block
did not significantly extend block performance time and provided, on average, over three hours more
pain relief compared to patients receiving a standard supraclavicular block. These results suggest that
administration of an ulnar nerve block in addition to a low-dose supraclavicular block is an efficient
and effective method of providing pain relief in the 24 hours following hand surgery in the ulnar nerve
distribution.
References:
1. Rawal N, et al. Anesth. Analg. 2001; 92: 347-51.
2. Smith BE, et al. Anaesthesia 1989; 44: 747-9
3. Fredrickson MJ, et al. Br. J. Anaesth. 2011; 107: 236-42
Funding disclosure: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research
and the Canadian Anesthesiologists' Society. Partial funding was provided by the Estate of the late
Mildred R. Weston.
Personal conflicts of interest disclosure: Nothing to disclose.
A16
THE ANALGESIC EFFICACY OF THE TRANSVERSALIS FASCIA PLANE BLOCK IN ILIAC
CREST BONE GRAFT HARVESTING
J. McVicar, H. Murgatroyd, A. Bhatia, B. Graham, V. Chan, K.J. Chin
1
2
Anesthesiology, Hand Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON,
Canada
Background: Iliac crest bone graft (ICBG) harvesting is associated with significant postoperative
pain. The Transversalis Fascia Plane (TFP) block is a novel technique targeting the subcostal,
1
ilioinguinal and iliohypogastric nerves that innervate the anterior iliac crest (Figure 1) . Local
anesthetics are injected into an interfascial plane between the deep investing fascia of transversus
2
abdominis and the transversalis (Figure 2) .
[Ultrasound Guided TFP Block]
[Sensory innervation of the anterior iliac crest. ]
Our objective was to determine whether an ultrasound (US)-guided TFP block provides effective
analgesia following ICBG harvesting.
Methods: We recruited adult patients undergoing ICBG harvesting and elective upper limb surgery
performed under brachial plexus block. Patients were randomized to receive an US-guided TFP block
with 20ml 0.5% ropivacaine with 1:200 000 epinephrine or 20ml of 5% dextrose solution (placebo).
Patients also received either a general anesthetic (GA) or spinal anesthetic according to their
preference. Opioids were administered in the operating room and the post anesthesia care unit
(PACU) at the discretion of the attending anesthesiologist. All patients were admitted to hospital
overnight and received IV PCA morphine.
Results: The data from 30 patients is presented. There were no differences in patient population in
terms of age, sex, BMI or surgery type. 53% of patients received the US-guided TFP block and 50%
underwent GA. Results are presented in Table 1.
TFP
Placebo
P Value
Pain Scores (0-10 visual analogue score (VAS))
VAS @ PACU
admission
0 (0-0)
3 (0-7)
0.008
VAS @ PACU
discharge
0 (0-2)
2 (1-5)
0.013
Average VAS in 1st 24h
2 (0-4)
4 (3-7)
0.026
Average VAS in 24-48h
2 (0-3)
4 (2-5)
0.057
Opioid Consumption (IV morphine equivalents in mg)
In PACU
0.5 ± 1.4
5.1 ± 4.9
0.002
PCA at 4h postoperative
1.2 ± 2.3
7.1 ± 6.5
0.004
PCA at 8h postoperative
6.6 ± 9.9
16.5 ± 9.9
0.035
[Opioid Use & Pain Scores at ICBG Harvest Site]
The intervention group had significantly lower pain scores at the hip in the PACU, and at 24 and 48
hours postoperatively. Opioid consumption was also significantly lower in the intervention group in the
following time periods: intraoperatively, in PACU, and at 4 hours and 8 hours post-operatively. There
was, however, no difference in total IV PCA morphine consumption.
Discussion: The TFP block provides effective analgesia at the ICBG harvest site, with discernable
effects up to 24-48h postoperatively. There was significant reduction in perioperative opioid
consumption up to 8h postoperatively in the intervention group. Total IV PCA morphine consumption
was similar between groups but we attribute this to pain at the primary surgical site once the brachial
plexus block had worn off.
References:
1. Hebbard PD. Transversalis fascia plane block, a novel ultrasound- guided abdominal wall nerve
block. Can J Anesth 2009; 56: 618-20.
2. Chin KJ et al. Ultrasound-guided transversalis fascia plane block provides analgesia for anterior
iliac crest bone graft harvesting. Can J Anesth 2012 59:122-123.
A17
PATIENT SIMULATION IMPROVES ANESTHESIOLOGY RESIDENTS' ABILITY TO MANAGE
LOCAL ANESTHETIC SYSTEMIC TOXICITY AS MEASURED BY WRITTEN AND CLINICAL
ASSESSMENT
1
1
2
1
B. Elmore , B. Ginter , J.-M. McGaugh , J. Dority
1
2
Department of Anesthesiology, University of Kentucky, Lexington, KY, University of New England
College of Osteopathic Medicine, Biddeford, ME, USA
Introduction: Patient simulation as a training technique allows learners to become familiar with
complex and rare facets of medical care with increased understanding of less-common complications
and improved patient safety. Recent studies suggest local anesthetic systemic toxicity (LAST) has an
incidence of 0.8-1.0/1000 regional blocks, making training in recognition and management of this
high-mortality complication ideally suited to simulation. Here we assess the use of the patient
simulator (PS) to enhance the training of residents in the management of LAST. A knowledge deficit
was identified in the learners' ability to recognize symptoms and initiate proper therapy. We
demonstrate better understanding and retention of key concepts when using simulation compared to
standard lecture only.
Methods: Anesthesia residents were organized into two groups. The first group participated in a PS
with LAST complicating an interscalene block. In the scenario the patient expresses anxiety that
progresses to seizure and cardiovascular collapse. The resident is expected to recognize the signs of
LAST and manage the patient appropriately. Two independent observers assessed the simulation
performance using an objective structured clinical examination (OSCE) based on a modified ASRA
checklist for treatment of LAST. Following the simulation encounter, residents' knowledge of LAST
was evaluated through a computerized pre-test. An anesthesiologist then explained management of
LAST during a 10-minute discussion period. Afterwards, the resident completed a second simulation
to reinforce concepts and foster retention. Finally, a post-test was administered followed by a Likert
scale survey for self-assessment of the activity.
The second group proceeded directly to the pre-test. Next, a 10-minute recorded lecture on LAST
management was shown to the resident. Residents were then administered the post-test and survey.
In two months, each participant will return for evaluation of LAST management concept retention
using a new PS with a checklist, post-test, and self-evaluation survey.
Results:
[Figure 1]
Figure 1. Average Percent Correct OSCE Items Pre- and Post-Discussion.
[Figure 2]
Figure 2. Average Percent Correct Items on Pre- and Post-Test.
(Error bars represent one standard deviation for both figures)
Figure 1 demonstrates immediate improvement in clinical skills as evaluated by our OSCE after our
discussion of LAST management in simulation.
Figure 2 reflects similar improvement in knowledge base. Subjective self-assessment (not included)
also shows increased resident confidence in ability to manage LAST after simulation and preference
for simulation training.
Discussion: PS provides residents with an opportunity to trial high-stress situations and rare events
without placing patients at risk. Our initial data indicate that residents show significant improvement in
their ability to manage LAST after simulation training when compared to didactic lecture alone. A poststudy exam and simulation will occur two months after primary teaching to allow comparative retention
analysis. Additionally, our LAST simulation will be incorporated into our 'rare event' curriculum, which
our department utilizes to simulate complex anesthetic cases such as cardiopulmonary bypass and
one-lung ventilation to facilitate improvement in clinical ability.
Funding Disclosure: None.
Conflicts of Interest: None to disclose.
A18
THE USE OF CEREBRAL OXIMETRY TO DETECT CEREBRAL DESATURATION EFFECTS IN
ARTHROSCOPIC SHOULDER SURGERY IN THE BEACH CHAIR POSITION
A. Francois, D. Salazar, B. Sears, P. Tonino, G. Marra
1
2
3
Anesthesiology, Orthopedics, Loyola University Medical Center, Maywood, IL, USA
Introduction: The beach chair position for arthroscopic shoulder surgeries is widely used by
orthopedic surgeons. This position has significant physiologic effects and can be a contributing factor
in reduction of cerebral perfusion intraoperatively, causing cerebral hypoxia. Cerebral oximetry has
been used in the surgical setting to monitor tissue oxygenation in the brain. In this study, we were
interested in the clinical sequelae of cerebral desaturation events, as well as risk factors for cerebral
desaturation in patients undergoing arthroscopic shoulder surgery in the beach chair position.
Material and methods: With IRB approval and informed patient consent, Regional Cerebral Tissue
Oxygenation (rSctO2) was measured in 50 patients undergoing arthroscopic shoulder surgery in the
beach chair position, using Near Infrared Spectroscopy (NIRS) (INVOS 5100, Somanetics, Troy, MI).
The patients were administered the Repeatable Battery for the Assesment of Neurophysiologic Status
(RBANS) test preoperatively the day of surgery to obtain a cognitive baseline. Bilateral cerebral
oximetry probes were placed for continuous monitoring. baseline noninvasive blood pressure and
rSctO2 were measured prior to interscalene block. All patients also had general anesthesia with
sevoflurane via LMA. rSctO2 was measured prior to induction, during patient positioning until the
conclusion of surgery. Patients were positioned in the semi upright position 80 degrees from
horizontal, with the head neutral. We defined a cerebral desaturation event (CDE) as a decrease in
rSctO2 of 20% or greater from baseline, and this was treated with ephedrine in 5mg increments, or
neosynephrine 80mg, crystalloid bolus, or returning the patient to supine. On postoperative day 3
when the patients returned to the clinic for follow-up and wound assessment, they were againg given
the RBANS exam. Patients were randomized to receive a dissimilar version of the RBANS A, B, C or
D from their preop exam. these were administered by research assistants trained in administration of
the test. The association between any intraoperative CDE and the pre- and post-operative RBANS
was assessed.
Results: Complete data sets were obtained for 50 patients meeting inclusion criteria. Nine patients in
our series had intraoperative desaturation events (18%) The RBANS did not demonstrate any
measurable difference between the pre- and post -operative exams. There was no significant
difference between the patients who experienced desaturation events and those who did not in
regards to age, gender, smoking history, coronary disease, obstructive sleep apnea, diabetes,
peripheral vascular disease or pulmonary disease. In 2 of the patients who experienced CDE below
20%, the procedure was temporarily suspended and the patients returned to supine to allow for
correction of the desaturation.
Discussion: Measurement of rSctO2 with NIRS can show when there is potential for mismatch
between cerebral oxygen supply and demand. Since a threshold for rSctO2 is not known, NIRS
allowed prompt identification and treatment of decreased cerebral perfusion pressure, preventing
catastrophic outcomes.
References:
1. Ghosh A, et al: Cerebral Near-Infrared Spectroscopy in adults. Anes Analg. 2012 Dec: 115: 137383
2. Pohl A. et al. Cerebra ischemia During Shoulder Surgery in the Upright Position. J. Clin. Anes.
2005: 17: 463-9
A19
ULTRASOUND GUIDANCE FOR BRACHIAL PLEXUS BLOCK DOES NOT AFFECT NERVE
DISTORTION IN COMPARISON WITH NERVE STIMULATION
1
2
2
J. Geerling , M. Harbell , P. Aleshi , P. Hess
1
1
Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center,
2
Boston, MA, Department of Anesthesia & Perioperative Care, University of California, San Francisco,
San Francisco, CA, USA
Introduction: Nerve injury after regional anesthesia is multifactorial. Nerve disruption due to needle
or fluid infiltration is believed to be a risk factor. Animal studies suggest intraneural injection causing
1
nerve expansion results in histologic but not functional nerve injury . Ultrasound has been suggested
to decrease risk of nerve injury by observation of needle placement and fluid injection. We
hypothesized that ultrasound guidance would reduce nerve disruption and possibly nerve injury.
Methods: After IRB approval and informed written consent, subjects underwent brachial plexus block
(interscalene - axillary) using either nerve stimulation (NS) or ultrasound (US) guidance, with 0.375%
bupivacaine and epinephrine 5mcg/ml. Onset time of motor and sensory blockade, duration of block,
and postoperative pain were recorded. Ultrasound images were taken immediately before and after
injection by a single observer. Images were reviewed by a blinded observer for location of the final
injection, whether a circumferential 'donut' was produced, and the degree of nerve disruption by
swelling or seperation, and were evaluated by ordinal scales and a 7-point Composite score. Block
failures were eliminated from the analysis. Data were reported as median (quartiles). Comparisons
were made using Mann-Whitney test, Fisher's exact, or Spearman correlation, as appropriate.
Results: 122 subjects completed enrollment, 89 NS and 33 US. Patient who had NS were more likely
to receive general anesthesia over sedation (74% vs. 52% P=0.03). No difference in onset of motor
block (9min (8-14) vs. 9min (6-11) P=0.22), duration (19hr (14-23) vs. 17hr (12-23) P=0.08), or
postoperative pain (0/10 in both groups) was found between NS and US, respectively. No difference
was found between groups in the value for nerve distortion or circumferential donut, but Composite
score was greater in the US group (3 (3-3) vs. 4 (3-5) P=0.03). Image scores correlated with each
other, but not with sensory block, motor block or with block duration. In the US group, the
circumferential donut score negatively correlated with duration (r=-0.46 p=0.02). No patient had nerve
injury from the anesthetic procedure.
[Comparison of US and NS blocks]
Discussion: Both blind injection technique (nerve stimulation) and ultrasound guidance produced
nerve bundle distortion and circumferential distribution of injected fluid. We were unable to distinguish
the technique by the distribution of the injectate. Nerve disruption is common with either US or NS
technique and did not appear to cause nerve injury. Furthermore, the visual evaluation of this spread
did not predict the onset or duration of blockade. In the ultrasound group, intentionally attempting to
create a donut outside of the bundle correlated with a shorter duration of blockade. In conclusion,
regardless of the technique of injection, nerve disruption is common during brachial plexus block, but
does not predict success or duration of the block.
1
Reference: Lupo CM.Histologic evidence of nerve injury with swollen nerve on US Reg Anesth Pain
Med. 2010;35:132.
Funding: Beth Israel Anesthesia Foundation
Personal conflicts of interest disclosure
Hess: consultation for Philips Ultrasound, Inc.
A20
WRONG SITE BLOCKS: 10 YEAR EXPERIENCE IN A LARGE MULTI-HOSPITAL HEALTH CARE
SYSTEM
M. Hudson, J.E. Chelly, J.P. Williams
Department of Anaesthesiology and Pain Medicine, University of Pittsburgh Medical Center,
Pittsburgh, PA, USA
Introduction: Wrong site nerve block is considered a serious reportable event (SREs) in healthcare
by the National Quality Forum (NQF) Board. Scarce reports based on anecdotal data have tried to
quantify this complication but it's frequency remains unknown, along with associated risk factors. This
study was conducted to assess the frequency of wrong site blocks in our large multi-hospital health
care system and review associated risk factors.
Methods: Using quality improvement and billing data, we established the number of wrong site blocks
occurring over a 10 year period between July 1 2002 - June 30 2012 within the University of
Pittsburgh Medical Center Health System (UPMCHS) under the supervision of the University of
Pittsburgh Physicians Department of Anesthesiology. During the study period the number of hospitals
performing blocks increased from 6 to 13. Prior to June of 2010, each hospital was responsible for
verification processes surrounding interventional nerve blocks. Following the wrong site block which
occurred in June 2010 a mandatory “time out policy” was developed by the Department. In March
2011, a system-wide “Prevention of Wrong Site Block” Policy was approved and introduced across all
system hospitals.
Results: With the exception of 1 hospital, all blocks were performed pre-operatively in a holding area.
During the study period wrong site blocks were performed on 9 patients, with an overall frequency of
1 per 10,000 patients. The incidence of wrong site blocks varied from 0 to 3 per year and 0 to 3 per
site. The distribution of wrong site blocks according to the time of occurrence, the hospital, the type of
blocks and the relative number of blocks performed is presented in table 1. Although wrong site
blocks were recorded after the development of a departmental and/or system-wide policy, in each of
these cases, review confirmed that the team did not follow approved policy; In one case, the team that
performed the block differed from the team performing the time out, in the second case, the time out
was performed before the patient was positioned and marked, and in the most recent case the
marking of the patient was not visible when the block was performed.
Year
Type of Block Performed
A
2005
Femoral
A
2006
Lumbar Plexus
B
2008
Femoral
C
2009
Femoral
B
2010
Cervical
D
2010
Interscalene*
E
2011
Femoral
A
2011
Lumbar Plexus
C
2012
Femoral
Hospital
*development of a
departmental system policy
[Table1]
Discussion: Our data suggest that risk factors for wrong site block include: 1.) the block performed
most often (in our case the femoral block), 2.) the number of blocks performed at a given site, 3.)
urgency for performing the block, 4.) lack of implementation of systematic prevention approach.
Recent data suggest this is an endemic problem. 1 Although, in the last quarter in Pennsylvania only
4 wrong side blocks (vs 7 wrong side surgery) were reported, it is important to recognize that in terms
of frequency wrong side block occur much more frequently than wrong side surgery. Data from our
institution indicates that wrong side blocks are still 6 times more frequent than wrong side surgery.
Conclusion: Prevention of wrong site blocks requires constant vigilance and engagement of every
member of the team involved in performing a well delineated verification and prevention process.
A21
ULTRASONOGRAPHIC CHARACTERIZATION OF THE PERSISTENT MEDIAN ARTERY IN
PEDIATRIC PATIENTS
G.R. Merritt, A. Nguyen, C. Ciarallo, D. Chatterjee, P. Carry, J. Park, F. Scott
1
2
Anesthesiology, Orthopedic Surgery, Children's Hospital Colorado, Aurora, CO, USA
Introduction: During embryologic development, perfusion to the forearm and hand is provided by the
1
median artery. While most median arteries regress by 8 weeks of intrauterine life, persistent median
2
arteries (PMAs) may be detected in up to 30% of the general adult population. Antebrachial median
arteries terminate in the proximal forearm and are normal, while palmar median arteries are
3
anatomical variants that terminate in the hand. PMA has been associated with carpal tunnel
4
syndrome, pronator teres and anterior interosseous syndromes.
A pediatric cadaveric study described a 44% prevalence of PMAs but was limited to neonates and
5
6
infants. Recently ultrasound has been used to identify the prevalence of PMA in adults . The purpose
of our study was to use ultrasonography to determine the prevalence of PMAs across a broader
pediatric population and to establish the relationship between age and defined regression points.
Methods: Following institutional IRB approval, patients undergoing orthopedic upper extremity
surgery were enrolled in the study. Demographic data was collected (i.e. age, gender, handedness,
ethnicity and race). Ultrasonographic examination was performed on both upper extremities using
Logiq e ultrasound machine and a high-frequency linear transducer (GE Milwaukee, WI). Length and
points of regression were documented for all PMAs. Mid P Exact tests and linear regressions were
used for statistical analysis.
Results: 137 limbs in 70 patients (40 male; 30 female; age range: six months to 18 years old) were
evaluated. 21/70 patients demonstrated PMAs. 9/21 presented PMAs bilaterally, 7/21 presented
PMAs in the right arm only, and 5/21 in the left arm only. The study cohort identified a total of 30
PMAs. The crude prevalence rate in individuals was 1 in 3 while the overall prevalence of PMAs was
2.19 per 10 limbs [95% CI: 1.51 to 3.09 per 10 limbs]. There was no difference in PMA prevalence
based on gender [p = 0.4986], ethnicity [p = 0.4365] or race [p = 0.05651]. The relationship between
age and the normalized percent regression point was also not statistically significant [p = 0.8455].
Discussion: The mid-forearm approach to a median nerve block has only recently been described
following advances in ultrasound technology. An awareness of PMA is important during the
performance of a mid-forearm block because of the risk of hematoma, compression neuropathy or
intravascular injection. Based on our preliminary results, the crude prevalence of PMAs in pediatric
patients is 1 in 3 individuals and 1 in 5 limbs. These numbers suggest a similar prevalence to reports
in the adult population. Additionally, our preliminary data did not show age-associated regression,
suggesting that post-natal regression may not be a relevant phenomenon.
A22
CHANGING METHODS OF ASSESSMENT OF PEDIATRIC ANESTHESIA FELLOWS' CLINICAL
UGRA PERFORMANCE BASED ON DISCORDANCE BETWEEN PRECLINICAL AND CLINICAL
EVALUATIONS
1
1
1
2
D. Moore , S. Clay , L. Ding , C. Eastwood , S. Sadhasivam
1
1
Cincinnati Children's Department of Anesthesia, Cincinnati Childrens Hospital/University of
2
Cincinnati, Cincinnati, OH, Department of Anesthesiology, New Hampshire's Hospital for
Children/Elliot Hospital, Manchester, NH, USA
Introduction: Assessment of trainee performance can be difficult. Educators seek to establish
procedural competency and safe practice benchmarks (1,2).
At our institution fellows are evaluated both preclinically and clinically. Using our real-time feedback
UGRA simulator and our cognitive exam, we have seen significant improvements for our fellows at 6
and 12 months of fellowship, compared to their baseline performance at the start of their fellowship
(3). Concurrently, we have been assessing our fellows' clinical regional anesthesia performance. In an
attempt to correlate the preclinical evaluation and the clinical evaluation, we discovered discordance
between the two evaluations. Our aims of this educational research are as follows: 1. Develop an
objective assessment tool for evaluation of clinical UGRA performance by pediatric anesthesia
fellows. 2. Utilize UGRA simulation to assess and improve UGRA technical and cognitive skills. 3.
Correlate preclinical testing and UGRA simulation with clinical performance of UGRA by pediatric
anesthesia fellows.
Methods: Pediatric anesthesia fellows had preclinical UGRA skill assessments at 0, 6 and 12 months
with our cognitive tests and UGRA simulation models (technical accuracy and efficiency) (3). When
fellows clinically performed regional anesthesia (with or without ultrasound) throughout the fellowship
year, supervising faculty evaluated their technical and cognitive skills using a 1 (poor) to 5 (excellent)
scoring system.
Results: 10 pediatric anesthesia fellows participated in the study over 1 academic year. Preclinical
cognitive and UGRA technical skills of all fellows improved at 6 and 12 months from baseline skills
(Figure 1). Faculty evaluations of clinical UGRA performance of fellows in terms of mean technical
and cognitive scores remained between 4 (very good) and 5 (excellent) (Figure 1). There was no
statistically significant correlation between preclinical and clinical assessments.
Discussion: Using our objective and standardized preclinical UGRA assessment tools, we were able
to identify fellows needing additional help at the beginning of the year and demonstrate overall
improvement in our fellows' cognitive and technical skills as the year progressed (3). When evaluating
clinical UGRA skills, scoring of this assessment, while still in a “good” to “very good” range, decreased
over time. Reasons for this included evaluators' subjective bias and temporal changes in
expectations. Also, there was a relatively small sample size, which may impact the ability to draw
correlations between preclinical and clinical assessments. Due to this discord between our
evaluations, we have created a more objective regional anesthesia assessment tool (Figure 2) based
on previous evaluation of behavior of regional anesthesia novices (4) that gives consideration to
performance time and block outcome, and thus, improving our ability to objectively assess UGRA
performance and competency.
References:
(1) Norcini et al. BMJ. 1999; 319(7218): 1183-5.
(2) Norcini. BMJ 2003; 326(7392): 753-755.
(3) Moore et al. Ped. Anesthesia 2012; 22(9): 847-853.
(4) Sites et al. RAPM. 2007; 32(2):107-115.
Funding: This project needed no additional funding.
Conflicts of interest: The authors have no conflicts of interest.
[Preclinical and Clinical Comparison]
[Procedural Performance Sheet]
A23
A SCOPING REVIEW OF THE EVIDENCE FOR TEACHING ULTRASOUND GUIDED REGIONAL
ANESTHESIA (UGRA)
C.M. Nix, C.B. Margarido, I.T. Awad, A. Avila, J.J. Cheung, A. Dubrowski, C.J. McCartney
1
2
Anesthesia, Sunnybrook Health Sciences Centre, Anesthesia, Sunnybrook and Women's College
3
Hospital, Obstetrical Anesthesia Research Unit, Learning Institute, SickKids, Toronto, ON, Canada
Introduction: Recent Ultrasound Guided Regional Anesthesia (UGRA) education literature has called
for our understanding of how anesthesia trainees develop ultrasound-guided clinical competency to
1
be based on firm scientific methodology . By advancing our knowledge of how best to teach and
learn the skills associated with UGRA, we can reach a consensus on how best to structure our UGRA
training programs. The purpose of this scoping review was to understand how UGRA is currently
taught, as well as to investigate the scientific evidence behind UGRA education. We sought to identify
key research priorities related to the future of UGRA education.
Methods: Our review accounted for published articles derived from the following databases on the
topic of UGRA education: US National Library of Medicine database; MEDLINE; the Excerpta Medica
database; Embase; the Cochrane Database of Systematic Reviews and the Cochrane Central
Register of Controlled Trials. We examined and summarized the extent, range and nature of the work
already done in this field. Qualitative content analysis was used to identify UGRA skill components
and emergent themes related to current teaching methods and future research priorities in UGRA
education.
Results: The search yielded 205 articles, of which 35 met the inclusion criteria and were included in
the final analysis (figure 1). Three major themes emerged from the literature which reflected the
different components of this complex skill:
(1) The development of proficient motor skills (the trainee learning curve and assessment methods for
UGRA trainees and practitioners);
(2) Learning sonoanatomy (correlating 3D anatomical structures to their appearance on a 2D
ultrasound image)
(3) Program set up (including equipment and educational tools) and program evaluation. We also
summarized the findings of recent surveys which looked specifically at UGRA education.
[figure 1]
Discussion: The UGRA education literature has reached a consensus on the skill components and
the indications of the proficient UGRA practitioner although some of the checklists in current use for
assessment need validation. An emerging evidence base supports the concept of pre-rotation
learning and demonstration of the skill followed by deliberate practice of simulated UGRA blocks with
supervised expert feedback. This is in order to shorten the trainee's learning curve and help them
attain proficiency before they reach the clinical setting. The importance of sonoanatomy interpretation
needs further evaluation as current UGRA trainees score poorly in this area. Evaluation and validation
of current UGRA programs is lacking. Research into the characteristics of effective trainers and
trainees has yet to happen. The concept of medical coaching is evolving but requires an evidence
base.
Reference: 1. Smith HM, Kopp SL, Johnson RL et al. Looking into learning: visuospatial and
psychomotor predictors of ultrasound-guided procedural performance. Reg Anesth Pain Med. 2012;
37:441-447.
Funding: None. No personal conflicts of interest.
A24
THORACIC EPIDURAL CATHETERS IN NEONATES: PRELIMINARY RESULTS OF AN
ALTERNATIVE IN-PLANE ULTRASOUND APPROACH
G. Rivera, C. Larraguibel, S. Cavallieri, M. Campos, M. Caceres
1
2
Department of Anesthesiology, Hospital Luis Calvo Mackenna, Department of Anesthesiology,
3
Clinica las Condes, Department of Anesthesiology, Clinica Santa Maria, Santiago, Chile
Introduction: Thoracic epidural blockade in neonates is challenging. Ultrasound guidance has been
used in these blocks. Nevertheless, the out-of-plane view and the necessity of a “second hand” make
this approach not so practical. Our aim was to evaluate the feasibility of the in-plane approach in a
transverse view by a single operator.
Material and methods: We obtained parent and/or IRB approval for the study. We recruited 32
neonates scheduled for surgeries suitable for thoracic epidural blockade under general anesthesia.
We used a Sonosite M-Turbo (Bothell, WA, USA) with its high frequency linear probe (13-6 Mhz). We
performed the blockades in lateral position visualizing the neuroaxis transversally. We advanced an
18G 50 mm tuohy needle, using an in-plane paramedian approach (fig-1). Once the epidural space
was identified and, with confirmation of standard loss-of-resistance technique, we introduced a 20G
catheter within the space (2-3 cm) (B. Braun, Melsungen, Germany). An initial bolus of 0,20%
levobupivacaine 1 mL/kg was administered via catheter and 30 minutes after we started an infusion of
0,04% levobupivacaine at rate of 0,2-0,4 mg/kg/hr.
We registered all data concerning demographic aspects and surgeries. During the puncture, we
recorded if the dura mater and the ligamentum flavum were identified or not. The analgesia was
assessed after extubation over 48 hr using the observational pain scale (OPS). The patients were
rescued with 0,04% levobupivacaine 1 ml/kg via catheter if OPS ≥ 11 or, if unsuccessful, IV morphine
was administered.
Results: The mean of age (range) and weight (SD) was 12 (0 - 27) days and 2,74 (1,23) kg,
respectively. The dura mater and the ligamentum flavum were identified in 100% and 94% of patients,
respectively. In all cases, a single operator handled the probe and placed the catheter without any
problem. The spaces T6-7 and T7-8 were the most frequent choice with 38% and 25%, respectively.
No dural puncture or hematoma was detected clinically. Eighty-four per cent of the cases were
extubated during the first 24 hr. The analgesia was considered effective in 80% of cases. Opioid
rescue was needed in 20%, because in these patients catheters were accidentally dislodged and/or
with an evident filtration.
[Transverse US view in-plane approach]
[A: T7-8 US image, B: Needle tip in epidural space]
Discussion: This report shows that the ultrasound transverse view of the neuroaxis with an approach
in-plane may be an alternative for neonatal thoracic epidural blocks. At this age, the sound beam
penetrates easily and offers a great detail of the needle tip. Despite of the technical difficulties
involved, this approach is achievable by a single operator without problem. Although, this technique
may represents an attractive alternative. There are some issues concerning evidence of safety, and
practical considerations in the post-operative period. Finally, if this approach is better than previous
approaches, remains to be elucidated.
References:
- Willschke H, Marhofer P, Bösenberg A, et al. Brit J Anaesth 97(2): 200-7, 2006
- Rapp HJ, Folger A, Grau T. Anesth Analg 101: 333-9, 2005
- Willschke H, Marhofer P, Bösenberg A, et al. Brit J Anaesth 95(2): 226-30, 2005
Conflict of interest: Nothing to disclose
A25
FOCUSED RISK ANALYSIS: REGRESSION MODEL BASED ON 5,314 PATIENTS UNDERGOING
TOTAL JOINT REPLACEMENT SURGERY AT A SINGLE INSTITUTION
S. Sinha, C. Lewis, I. Inneh, D. Smith, S. Schutzer, R. McAllister, E. Silverstein
1
2
3
Anesthesiology, Orthopedics, Connecticut Joint Replacement Institute / St. Francis Hospital and
Medical Center, Hartford, CT, USA
Introduction: Complications following total joint arthroplasty (TJA) surgery lead to poor functional
outcomes. Identifying patients at increased risk for complications will permit risk stratification and
optimization pre-operatively. The objective of this study was to identify independent pre-operative risk
factors that:
1. Increase the risk of re-operation in same admission
2. Prolong length of stay (LOS) >4 days in patients undergoing TJA
3. Increase risk of re-admission within 30 days of index surgery
4. Increase risk of serious orthopedic complication
5. Increase risk of major non-orthopedic complication
Methods: Data from 5314 patients undergoing primary TJA at the Connecticut Joint Replacement
Institute from October 1, 2008 to September 30, 2011 were obtained from our joint registry and
hospital databases. Data were collected on demographic variables, surgical information and comorbidities from the following nine (9) body systems. Logistic multivariate regression analysis (alpha <
0.05) was conducted to serve as the basis for a risk prediction tool. Based on the presence of
statistically significant predictors, an equation was generated for prospective use in our center
regarding the likelihood of developing complications or readmission in future patients.
Results: The incidence of re-operation on same admission was 0.2%. History of UTI or urinary
retention (Risk Ratio (RR)7.57;p=0.003) and blood disease(thrombocytopenia) (RR8.80;p=0.047)
predicted increased risk of re-operation.
Length of stay was greater than 4 days in 0.8% of patients in this cohort.
Variables
Risk Ratio
95% CI
Operating Time
(mins)
1.02
1.01
1.02
0.000
Coronary Artery
Disease
3.72
1.74
7.94
0.001
Chronic Renal
Failure
6.78
2.93
15.7
0.000
Blood Disease
9.4
2.08
42.5
0.004
Neoplasm
8.69
1.72
43.9
0.009
Delirium
59.0
18.4
189.7
0.000
Psychosis
28.6
2.83
2888.1
0.004
Transient Mental
Disorder
50.7
4.54
567.1
0.001
[LOS>4 days]
p value
The re-admission rate within 30 days of index surgery was 2.8%.
Variables
Risk Ratio
95%CI
P value
Age
2.12
1.38
3.26
0.001
Procedure
(TKA:THA)
0.670
0.48
0.934
0.018
Operating
time(mins)
1.01
1.00
1.02
0.003
CVA/TIA
3.04
1.57
5.90
0.001
Diabetes
2.01
1.39
2.91
0.000
PE/DVT
2.19
1.20
4.00
0.10
Depressive
Psychosis
14.2
1.44
140.5
0.023
[Readmit with 30 days]
The risk factors predicting increased risk of orthopedic and major non-orthopedic complications are
listed in the table.
[Table 3]
A Prediction Equation was generated:
Probability of a Primary Endpoint/Complication={OR/(1+OR)};
Where OR=exp{log(p/1-p)};
Log(p/1-p) = a+bx1+bx2 + bx3.....
X=predictor variable, b=beta coefficient, a=intercept/constant
Discussion: This predictive tool needs to be applied prospectively to a validation cohort.Funding: No
external Funding.
A26
IMPACT OF AN ACUTE PAIN SERVICE ON EPIDURAL CATHETER REPLACEMENT RATES
USED FOR POSTOPERATIVE ANALGESIA IN A CANCER HOSPITAL
J. Su, J.M. Soliz, K.U. Popat, R. Gebhardt
Anesthesiology and Perioperative Medicine, MD Anderson Cancer Center, Houston, TX, USA
Introduction: Reasons for failed epidural analgesia are multiple. Some reasons for inadequate
epidural blockade include incorrect placement, epidural catheter migration, and suboptimal dosing.
Definition of failed epidural analgesia varies in the literature. Reported epidural failure rates range
1
from 13% to 47.1%. In this study we define an epidural failure if the epidural catheter required
replacement. In our institution specializing in cancer treatment, epidural catheters are placed by
resident and faculty anesthesiologists for postoperative analgesia primarily for open thoracic and
abdominal procedures. Epidural analgesia is managed postoperatively by APM (Acute Pain Medicine)
service consisting of residents, acute pain nurses, and APM faculty. We reviewed the incidence,
causes of epidural replacements, and describe interventions to decrease epidural replacement rates.
Methods: After approval from Institutional Review Board, the number of thoracic and lumbar epidural
catheters used for postoperative analgesia was obtained from our billing database from January 1,
2006 to December 31, 2011. Using our APM database, a search was performed for all epidural
replacements documented from 2006 to 2011. An audit was performed documenting indications for
replacement from January 1, 2007 to December 31, 2007. The number of epidurals performed with
resident involvement in 2007 was obtained from our electronic anesthesia record database.
Interventions included presentations on epidural management in early 2008 and 2010 along with
notifications to practitioners after epidural replacements. We regressed proportion of epidural
replacements and lumbar epidurals by year to obtain trend over time provided by slope of regression
line. P-values corresponding to use of linear regression to test if slope of line was significantly
different from zero were reported.
Results: 11,769 epidural catheters were billed for postoperative analgesia from 2006 to 2011
consisting of 93.7% (n=11,026) thoracic and 6.3% (n=743) lumbar epidural catheters. Replacement
rates peaked in 2007 at 7.4% (n=181). In 2007, 12.4% of all epidurals initially performed had resident
participation. Of the replaced epidurals in 2007, 20% (n=36) initially involved residents, and 80%
(n=145) involved faculty anesthesiologists. 86% (n=156) of replacements initially involved non-APM
anesthesia personnel and 14% (n=25) involved APM personnel. Indications for replacement included
64% (n=114) with no sensory block obtainable, 16% (n=29) catheter migrated out, 15% (n=27)
inadequate analgesia due to low sensory block and/or lower extremity weakness, and 5% (n=11) due
to other causes. Lumbar epidural placements decreased from a peak of 12.1% in 2006 to 2.4% in
2010. A significant trend in decreasing epidural replacements of 1.1% per year (p=0.017) and lumbar
epidurals of 2.0% per year (p=0.002) were found. Lowest rates of replacement, 1.9%, occurred in
2010 and 2011.
[Decreasing trend 1.1% per year (p=0.017)]
[Decreasing trend 2.0% per year (p=0.002)]
Discussion: Significant lower incidence of epidural catheters requiring replacement was found after
educational presentations and feedback. Future analysis will include current indications for epidural
replacements in efforts to continue to decrease epidural failures.
References: 1. Hermanides J, Hollmann MW, Stevens MF, Lirk P. Failed epidural: causes and
management. Br J Anaesth. 2012 Aug;109(2):144-54. Epub 2012 Jun 26. Review.
A27
EPIDURAL CATHETER WITH INTEGRATED LIGHT GUIDES TO DETECT MALPOSITION: A
PORCINE MODEL FEASIBILITY STUDY
S.J. West, R. Del Soto, S. Putnis, J.C. Hebden, A.E. Desjardins
1
2
Anaesthetic Department, University College Hospital, London, Medical Physics and Bioengineering,
3
University College London, Orthopaedic Department, University College Hospital, London, London,
UK
Introduction: Epidural catheter insertion is a blind technique that involves a significant rate of
malposition. For instance, in obstetric anaesthesia, the rate of initial intravascular placement is 5-7%
(1). Malposition has serious consequences, which include local anaesthetic toxicity that can take
place when a catheter enters a blood vessel. Aspiration of blood is unreliable and test dosing with
epinephrine not recommended in parturients (1). Recent studies have demonstrated that
measurements of optical reflectance can provide information relevant for tissue differentiation during
needle insertions (2,3). In this study, we present a novel optical catheter with integrated light guides
that allows for measurements of optical reflectance to be acquired from tissues at the distal tip.
Material and methods: A custom epidural catheter with four integrated light guides was developed
with a polymer extrusion process (Fig. 1).
[Figure 1]
Broadband visible and near-infrared light was delivered through one light guide, where it was
absorbed and scattered in tissue at the distal tip of the catheter; a portion of the scattered light was
collected by a second light guide and measured with a spectrometer. To determine the feasibility of
optical tissue differentiation, measurements were acquired during a post-mortem laminectomy of a
swine, with the catheter manually positioned on exposed tissues (Fig. 2).
[Figure 2]
The swine had been sacrificed as part of an unrelated ethics-approved experiment.
Results: All of the spectra acquired from tissues exhibited features that were consistent with the
presence of haemoglobin, which is known to be a prominent absorber of light in the wavelength range
of 500 to 600 nm. Prominent differences between the spectra acquired from venous blood and all
other spectra were observed. In particular, the features associated with haemoglobin absorption were
more pronounced in spectra acquired from blood than those acquired from epidural fat, and the
average intensity of the former spectra was lower than that of the latter by a factor of 31.
Discussion: An epidural catheter has previously been considered a passive device; we have
demonstrated that catheters can include active optical components that allow for tissue sensing
without changes to their dimensions. The results of this study highlight the potential of optical
reflectance sensing as a novel method for detecting catheter malposition, both immediately after
placement and over the duration of infusion.
References:
1. J. Guay. “The epidural test dose: a review”. Anesthesia & Analgesia.102(3):921-929 (2006).
2. C. Ting, M. Tsou, P. Chen, et al. “A new technique to assist epidural needle placement:
Fiberoptic-guided insertion using two wavelengths,” Anesthesiology.112(5),1128-35 (2010).
3. Rathmell JP, Desjardins AE, van der Voort M, et al. “Identification of the Epidural Space with
Optical Spectroscopy: An In Vivo Swine Study,” Anesthesiology. 113(6):1406-18 (2010).
Funding disclosures: Equipment costs were met by a Royal Society grant.
Personal conflicts of interest disclosure: Nothing to disclose
A28
PARAVERTEBRAL BLOCKS FOR AMBULATORY BREAST TUMOUR RESECTION: EFFECTS
OF AN INHALATIONAL GAS- AND OPIOID-FREE ANESTHETIC ON THE QUALITY OF
RECOVERY. RANDOMIZED CONTROLLED TRIAL
F.W. Abdallah, P.J. Morgan, T. Cil, A. McNaught, J. Escalon, J. Semple, V.W. Chan
1
2
Anesthesiology, Surgery, University of Toronto, Toronto, ON, Canada
1
Background: Current evidence associates tumor recurrence and metastasis with postoperative pain,
2-5
6-8
6, 9-11
surgical stress, inhalational anesthetics, and opioid use.
Consequently, regional anesthesia
12-15
16
techniques are advocated
for tumor resection surgery as they effectively treat surgical pain,
17
attenuate the neuroendocrine stress response, and minimize the use of general anesthetics and
opioids. This study examines the effects of using an inhalational gas- and opioid-free anesthetic
technique that relies on total intravenous anesthesia (TIVA) and thoracic paravertebral blocks (PVBs)
on the quality of recovery (QoR) following ambulatory breast tumor resection.
Methods: Sixty-six adult females undergoing breast tumor resection surgery were randomized to
receive a standardized general anesthetic regimen inclusive of sevoflurane, fentanyl, and morphine
(General Group) or a combination of PVBs and propofol-based anesthesia (PVB Group). The PVB
group received 5mL of ropivacaine 0.5% in each of the T1-T5 paravertebral spaces on the operative
18
side using an out-of-plane parasagittal technique. The General group received five-level sham
blocks with subcutaneous saline. QoR was assessed before discharge and on postoperative day
7
(POD) 2 using the QoR questionnaire. Secondary outcomes including pain scores on admission and
discharge from post-anesthesia care unit (PACU), discharge from hospital, and POD2; intra- and
postoperative opioid consumption; time to first analgesic request; incidence of nausea and vomiting
(PONV); patient satisfaction; and discharge time were assessed.
Results: Data from sixty-four patients was analyzed. Patient demographics were similar between
groups (Table 1). The QoR score before discharge and on POD2 was superior in the PVB group;
146(143-149) and 144(141-149) versus 131(126-135); P< 0.0001 and 138(131-145); P= 0.013,
respectively in the General group (Figure 1). Pain scores were also lower in the PVB group on
admission and discharge from PACU, discharge from hospital, and on POD2 (Figure 2).
Intraoperative morphine consumption, incidence of PONV, and discharge time were lower in the PVB
group (Table 2). The groups did not differ in postoperative morphine consumption, time to first
analgesic request, and patient satisfaction.
Conclusion: Combining propofol-based general anesthesia and PVBs provides superior quality of
recovery, analgesia, and shorter discharge time than an inhalational and opioid-based anesthesia in
patients undergoing ambulatory breast tumor resection.
Parameter
USG-PVB (n=33)
General anesthesia (n=31) P-value
Age (years)
53.1 +/- 12.3
56.5 +/- 12.5
0.14
Height (cm)
164.9 +/- 7.6
161.5 +/- 6.1
0.27
Weight (kg)
68.0 +/- 9.4
67.6 +/- 12.3
0.35
BMI (kg/m2)
24.7 (22.2-28.2)
24.7 (21.0-31.7)
0.73
ASA classification (I/II)
11/22
13/18
0.48
[Patient characteristics]
General anesthesia
(n=31)
P-value
Intraoperative. morphine
1.67 +/- 3.04
consumption
15.94 +/- 7.76
<0.0001
Postoperative. morphine
10.59 +/- 13.45
consumption
14.55 +/- 14.69
0.27
Time to first analgesic
request
58.22 +/- 36.52
68.57 +/- 81.01
0.59
Incidence of PONV
3/33
12/31
0.004
Time to discharge
190.19 +/- 51.58
239.87 +/- 78.35
0.005
Patient satisfaction
9.8 +/- 0.5
9.5 +/- 1.0
0.13
Outcome
USG-PVB (n=33)
[Results]
[Figure 1]
[Figure 2]
A29
ULTRASOUND-GUIDED SCIATIC NERVE BLOCK FOR TOTAL KNEE ARTHROPLASTY: A
COMPARISON OF THE SUBGLUTEAL SPACE AND THE INFRAGLUTEAL INJECTION
TECHNIQUES. RANDOMIZED CONTROLLED TRIAL
F.W. Abdallah, V.W. Chan, A. Koshkin, R. Brull
Anesthesiology, University of Toronto, Toronto, ON, Canada
Background: Sciatic nerve block (SNB) can provide clinically significant analgesia in total knee
1,2
3, 4, 5
arthroplasty (TKA),
but it is among the least performed peripheral blocks.
Challenges
associated with SNB include technical difficulty, procedural discomfort, and unreliable success,
6, 7
8
particularly in obese patients.
The ultrasound (US)-guided infragluteal approach to SNB can
9
reduce local anesthetic requirements compared to traditional blind techniques. However, US does
10
not overcome the challenges posed by anatomical depth. Rather than directly targeting the sciatic
nerve itself, the recently described US-guided “subgluteal space” technique for SNB may hasten
performance time and potentially reduce complications by injecting local anesthetic in the facsial
plane between the readily-identifiable gluteus maximus and biceps femoris muscle at the level of the
11
greater trochanter and ischial tuberosity. We primarily aimed to evaluate the time to perform novel
subgluteal space technique compared to infragluteal approach to SNB in TKA patients. Procedurerelated discomfort, adverse events, postoperative opioid consumption, pain scores, and side effects
were also assessed.
Methods: Twenty-eight patients undergoing US-SNB for unilateral TKA under spinal anesthesia and
continuous femoral block were randomized to either a subgluteal space or an infragluteal techniques.
We injected 30mL local anesthetic admixture (10mL lidocaine 2% mixed with 20mL bupivacaine 0.5%
with 1:400,000 epinephrine) in all patients. Sensory and motor functions were assessed up to 30min
by a blinded observer. The primary outcome was performance time.
Results: Twenty-seven patients were analyzed. Patient characteristics were similar between groups.
The block procedure time was 4.36+/-1.28 min in the subgluteal space group and 9+/-2.35 min in the
infragluteal group (P< 0.00001) (Table 1). Procedural pain scores were lower in the subgluteal space
group (Figure 1). The complete sensory and motor block rates in the tibial and common peroneal
nerves at 30min did not differ between groups (Figure 2). There was no difference between the two
groups in the procedural sedation requirements (Table 1), postoperative rest pain scores (Figure 1),
time to first analgesic request, and cumulative 24h morphine consumption (Table 1). Three patients in
the infragluteal group developed transient paresthesias in the tibial nerve distribution that lasted up to
one week.
Conclusion: The subgluteal space SNB technique is faster and less traumatic to perform, with no
detectable differences in block success and cumulative 24-hr postoperative opioid consumption.
Future larger studies are needed to investigate potential differences in analgesic efficacy of the two
techniques.
Subgluteal space
Infragluteal
P-value
Block procedure time
(min)
4.36 +/- 1.28
9 +/- 2.35
0.000007
Circumferential spread
achieved
2/14
12/13
0.0009
Pain VAS score during
block
1.32 +/- 1.20
2.27 +/- 1.51
0.043
Midazolam requirements
1.96 +/- 0.66
during block (mg)
2.14 +/- 0.77
0.26
Time to first analgesic
request (min)
11.15 +/- 10.32
0.29
Cumulative 24 hour oral
morphine equivalent
126.38 +/- 82.35
consumption (mg)
138.25 +/- 79.93
0.7
Incidence of PONV
9/14
10/13
0.48
Incidence of block
complications on day 7
0/14
3/13
0.15
[Results]
[Figure 1: Pain scores]
13.28 +/- 9.46
[Figure 2: Block onset]
A30
COMPARATIVE EVALUATION OF STIMULATING CATHETERS TO ECHOGENIC NEEDLE AND
CATHETER FOR SCIATIC BLOCK: A RANDOMIZED PROSPECTIVE STUDY
J. Brookes, R. Sondekoppam Vijayashankar, S. Ganapathy, K. Armstrong, S. Dhir, M. Terlecki
Anesthesiology and Perioperative Medicine, London Health Sciences Centre, University of Western
Ontario, London, ON, Canada
Introduction: Visibility of needle tip and catheter tip are essential to perform safe and successful
peripheral nerve blocks. This can be challenging with the use of ultrasound in obese patients.
Echogenic needles and catheters may facilitate positioning of the catheter tip correctly. This study
comapares the safety and efficacy of the echogenic system with the traditional stimulating catheter
system.
Material and methods: Seventy patients scheduled for total knee joint arthroplasty willing to have a
continuous femoral and sciatic blocks were randomized to receive the sciatic block either using the
stimulating catheter system with the needle positioned with ultrasonography and neurostimulation or
using the echogenic needle and catheter to position the catheter using only ultrasound. All blocks
were done with Sonosite M Turbo machine with a curved array 3-5MHz probe with the patient in the
lateral decubitus.The number of attempts, time to first twitch, time to complete insertion of catheter
and number of needle and catheter redirections were recorded. Catheter tip location was also
assessed using color doppler. The entire loops of ultrasound recording was given to 2 independent
blinded researchers to grade the visibility of the needle and the catheter tip on a categorical scale of
1-3, 3 being the best view.The sensory motor block was evaluated every 5 mins for the next 30
minutes.
Results: The demographics were similar between the groups.(Table 1) The visibility of the needle
and the catheter were better with the echogenic system but the onset and completeness of the block
was better with the stimulating catheter.There was no difference in the time required to insert the
catheters in the acceptable location. The number of needle redirections and catheter reinsertions
were lower in the echogenic group.
Discussion: This is a preliminary report of a total of 44 patients out of the 70 randomised and we will
present the final data at the meeting.The echogenic system allows fewer passes of the needle and
fewer redirection of the needle. The onset of block is much faster with the stimulating technique.
References:
1. Needle visualization in ultrasound-guided regional anesthesia: challenges and solutions Chin, KJ,
Perlas A, Chan, VWS, Brull, R. Regional anesthesia and pain medicine 2008;33:532-544
2. Investigation of a new echogenic needle for use with ultrasound peripheral nerve blocks. Deam RK,
Kluger R, Barrington MJ, McCutcheon CA. Anaesth Intensive Care. 2007 Aug;35(4):582-6.
Variable
Stimulating N=26
Echogenic n=18
P value
Age in yrs(SD)
65.03 (10.3)
66.1 (11.4)
0.7
Male/Female
12/14
7/11
0.6
Weight in KG (SD)
87.3 (15.2)
89.2 (22.4)
0.7
Height in cm(SD
165.4 (9.1)
166.4(10.7)
0.7
BMI (SD)
31.8(4.7)
31.6(5.8)
0.9
Time to first twitch
sec(SD)
163.9(126.7)
150.1(162)
0.75
Cath ins end sec(SD)
424.9(234)
346.9(183)
0.2
No. of Needle
redirection (SD)
2.03(1.8)
0.78(0.9)
0.01*
No. cath redirection
(SD)
0.46(0.8)
0.056(0.24)
0.046*
[Demographics]
[Block Progress compare]
A31
OPTIMAL PLACEMENT OF INTRA-ARTICULAR CATHETERS FOR DIFFUSION OF ANALGESIC
IN TOTAL KNEE ARTHROPLASTY
C. Press, G. Votta-Velis, K. Chakour, A. Borgeat, M. Gonzalez
1
2
3
Orthopaedics, Anesthesia, University of Illinois at Chicago, General Surgery, University of Chicago,
Chicago, IL, USA
When placing an intra-articular pain catheter within the knee for post operative analgesia, we
recommend placement within the supra-patellar space to achieve superior diffusion within the joint.
Background: Continuous Wound Infusion (CWI) techniques have been used in Total Knee
Arthroplasty to decrease post operative pain. Previous studies using CWI catheters utilize a wide
variety of approaches for catheter placements which may have important implications in the overall
diffusion of the administered local anesthetic. In our review of the literature, there is no study that
provides guidance to optimal catheter position. The purpose of this study was to determine the
position of the catheter which provided the maximum amount of volume dispersion within a total knee
arthroplasty.
Methods: Six cadaveric knees underwent total knee arthroplasties using standard techniques with
catheters placed in one of three locations: Supra-patellar, Medial Gutter, Lateral Gutter. The catheters
were infused with radio-opaque dye and placed on a continuous passive motion (CPM) machine for
one hour. Fluoroscopic images were obtained at regular time intervals (0, 1, 5, 60 mins) to identify
diffusion patterns within the joint. Areas of the knee were considered infiltrated when dye was visible
at pre-determined anatomic landmarks.
Results: Superior global diffusion rates were achieved with the catheter placed in the supra-patellar
pouch over both the medial or lateral gutters. Posterior capsular diffusion (as detected by dye visible
superior to the femoral condyles) was achieved in all catheter positions and found to be similar.
Anterior capsular diffusion (detected by dye penetrance at the inferior pole of the patella) was found
only to take place in the supra-patellar position.
Conclusion: When placing an intra-articular pain catheter within the knee, the supra-patellar space
achieved superior diffusion within the joint compared to both the medial and lateral gutters. This
anatomic position may also confer additional benefits to early rehabilitation by limiting the risk of
entrapment of the catheter within the femoral and tibial component during early range-of-motion
exercises. By defining a catheter placement technique, we hope to impart greater efficacy to these
devices and help standardize a location for optimal pain control.
A32
CHOICE OF ANESTHESIA TYPE AND PERIOPERATIVE OUTCOMES IN PATIENTS WITH SLEEP
APNEA UNDERGOING TOTAL JOINT ARTHROPLASTY: A POPULATION-BASED STUDY
1,2
1,2
1
1
1
1
1
T. Danninger , O. Stundner , R. Rasul , X. Sun , Y.-L. Chiu , P. Fleischut , M. Mazumdar , S.G.
1
Memtsoudis
1
Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell
2
University, New York, NY, USA, Department of Anesthesiology, Perioperative Medicine and Intensive
3
Care Medicine, Paracelsus Medical University, Salzburg, Austria, Division of Biostatistics and
4
Epidemiology, Department of Public Health, Weill Medical College of Cornell University, Department
of Anesthesiology, NewYork-Presbyterian Hospital, Weill Medical College of Cornell University, New
York, NY, USA
Introduction: The presence of SA among surgical patients has been associated with significantly
increased risk of perioperative complications [1]. Although regional anesthesia has been suggested
as a means to reduce complication rates among SA patients undergoing surgery [2], no data are
currently available to support this approach.
Material and methods: We analyzed data from 400 US hospitals. Patients who underwent primary
hip or knee arthroplasty with a concomitant diagnosis of sleep apnea between 2006 and 2010 were
identified. Perioperative outcomes were compared between patients undergoing surgery under
general, neuraxial, and combined neuraxial-general anesthesia. The independent impact of the
anesthesia technique on outcomes was assessed.
Results: We identified 44,086 entries for patients with a diagnosis for SA undergoing primary hip or
knee arthroplasty. 32,641 (74%) had information about anesthesia type available. Approximately 10%
of cases were performed under neuraxial, 14% under combined neuraxial and general and 76%
under general anesthesia. Patients undergoing their procedure under neuraxial anesthesia had
significantly lower rates of major complications compared to those undergoing surgery under
combined neuraxial/general or general anesthesia (16.0%, 17.0% and 17.9%, P=0.0262). Rates of
pulmonary, gastrointestinal and infectious complications as well as acute renal failure in particular
were higher in those undergoing surgery involving a general anesthetic compared to a neuraxial
approach. Utilization of transfusions, mechanical ventilation and critical care services were
significantly lower in the neuraxial and combined neuraxial and general groups than in the general
anesthesia group. When controlling for covariates, the odds for combined major complications were
lower among patients receiving neuraxial anesthesia compared to general anesthesia (Odds Ratio
(OR)=0.89, 95% CI 0.81-0.98,p=0.02; OR=0.84, 95% CI 0.75-0.74, p=0.002).
Discussion: Barring contraindications, neuraxial anesthesia should be considered as the anesthetic
of choice in patients with SA undergoing joint arthroplasty. Further research is needed into the
mechanisms by which neuraxial anesthesia confers beneficial effects compared to the general
approach.
References:
1. Kaw R, Pasupuleti V, Walker E, Ramaswamy A, Foldvary-Schafer N. Postoperative complications
in patients with obstructive sleep apnea. Chest 2012;141:436-441.
2. Gross JB, Bachenberg KL, Benumof JL, et al. Practice guidelines for the perioperative
management of patients with obstructive sleep apnea: a report by the American Society of
Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea.
Anesthesiology 2006;104:1081-93
A33
TRANSVERSUS ABDOMINIS PLANE (TAP) BLOCK IN RENAL ALLOTRANSPLANT
RECIPIENTS: A RETROSPECTIVE CHART REVIEW
L. Bejar, S. Gopwani, M. Rosenblatt
Department of Anesthesiology, Mount Sinai School of Medicine, New York, NY, USA
Introduction: A TAP block targets the ventral rami of T7-L1, which carry somatic sensory nerves to
the anterior abdominal wall. While some studies have shown significant opiate-sparing effects of the
1
2
TAP block , this finding has not been consistent across all intra-abdominal procedures .
A 2010 study of 20 patients found TAP blocks resulted in significant decreases in morphine
3
consumption during the first 24 hours following renal allotransplant . This was controverted in 2012, in
a randomized controlled trial of 65 patients showing no difference in morphine consumption at any
4
time point after surgery . TAP blocks in the latter study were performed without ultrasound guidance.
Materials and methods: IRB approval was obtained. The anesthesia information management
system, CompuRecord (Philips Medical, Andover, MA), was queried for all renal allotransplants from
May 1, 2011 through September 15, 2011. Data extracted included details of block placement,
intraoperative narcotic administration, and post-operative narcotic consumption over the subsequent
48 hours.
TAP blocks were performed under direct visualization with an M-Turbo ultrasound machine (Sonosite
Inc., Bothell, WA) using an L25x/13-6MHz broadband linear array probe. A 22-gauge 50mm block
needle placement was inserted in an in-plane medial to lateral approach.
Results: Our query resulted in 50 renal allotransplant patients. 13 patients received TAP blocks, 8
pre-incision and 5 post-operatively. 37 patients received no block. All blocks were ultrasound guided
in the manner described, with an injection of 20ml of 0.25% bupivicaine.
Data analysis was with unpaired t-tests. Baseline characteristics did not differ significantly.
Block (n=13)
No Block (n=37)
p-value
Age
47.57
53.73
0.1968
Weight (kg)
75.85
78.505
0.6647
Duration of Surgery
(min)
227
196.65
0.0993
Intraoperative
Fentanyl (mcg)
405.36
447.97
0.3968
Intraoperative
Fentanyl (mcg/kg)
5.3307
5.7192
0.4069
[Baseline Patient Charecteristics]
A statistically significant difference in post-operative narcotic consumption was found at all time points
post-operatively.
[Figure 1: Cumulative Narcotic Administration]
Discussion: Considering its retroperitoneal position and complete visceral denervation, renal
allotransplantation provides the most unambiguous opportunity to assess the TAP block. This review
shows significant reductions in morphine equivalent consumption over multiple time points, confirming
the findings of Mukhtar, et al., and disputing those more recently published by Fried, et al. Ultrasound
guidance is likely an integral component of TAP block efficacy.
A double-blinded randomized controlled trial assessing ultrasound guided TAP blocks for renal
allotransplants has been undertaken by this group.
References:
1. "Randomized clinical trial of transversus abdominis plane block versus placebo control in live-donor
nephrectomy." Hosgood, et al. Transplantation. 2012 Sep15;94(5):520-5
2. "Transversus abdominis plane block does not provide additional benefit to multimodal analgesia in
gynecological cancer surgery." Griffiths, et al. AnesthAnalg. 2010 Sep;111(3):797-801
3. "Transversus abdominis plane block for renal transplant recipients." Mukhtar, et al. BrJAnaesth.
2010 May;104(5):663-4
4. "Transversus abdominis plane block for analgesia in renal transplantation: a randomized controlled
trial." Freir, et al. AnesthAnalg. 2012 Oct;115(4):953-7
Funding: None
Personal conflicts of interest disclosure: Nothing to disclose
A34
SUCCESSFUL FEMORAL NERVE BLOCKADE IN OBESE AND NON-OBESE PATIENTS USING
A MODIFIED “2-IN-1” TECHNIQUE
M. Hogan, T.J. Ozelsel, B.C.H. Tsui, Edmonton Academy of Regional Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Femoral nerve blocks provide excellent lumbar plexus anesthesia; however, the
1
optimal approach remains debatable. Some groups claim that the traditional, 3-in-1 approach can
2
block the femoral, lateral femoral cutaneous, and obturator nerves consistently, while others claim
3
that the obturator nerve cannot be blocked using this method. The objective of this study was to
assess the clinical efficiency of a modified, “2-in-1” technique and to investigate the effect of body
mass index (BMI) on block procedure time and sensory and motor block onset times.
Material and methods: After institutional ethics approval, patients scheduled for femur surgery were
recruited to receive a “2-in-1” femoral nerve block for post-operative pain management prior to a
general anesthetic for surgery. Under ultrasound and using the femoral artery as a landmark, the
needle was advanced in-plane through the fascia lata and the fascia iliaca lateral to the femoral nerve
(Figure).
[Figure]
A test dose of dextrose 5% in water was injected to confirm needle tip position, and 20 mL of a local
anesthetic mixture (ropivacaine 0.5% + bupivacaine 0.125%) was injected. The needle was then
withdrawn to a position between the fascia lata and the fascia iliaca, and another 20 mL of the local
anesthetic mixture was injected. Patient weight and height were recorded, and procedural time, time
to first onset of sensory blockade, and first onset of motor blockade were compared between obese
2
2
(BMI >30 kg/m ) and non-obese (BMI < 30 kg/m ) patients.
Results: Fifty-two patients were recruited, and 16 (30.8%) were classified as obese. The mean BMI
of obese patients was 35.8 ± 6.0 versus 24.3 ± 4.2 for non-obese patients. One obese patient
required a supplementary regional block, yielding a success rate of 98% in this group; we achieved
100% success for the non-obese group. The onset of both sensory (10.7 ± 6.2 min non-obese vs.
16.3 ± 6.7 min obese; p=0.003) and motor (18.6 ± 6.1 min non-obese vs. 22.5 ± 3.9 min obese;
p=0.028) block was significantly longer for obese patients. The block procedure time was also
significantly longer for the obese group (208.1 ± 15.7 sec vs. 182.6 ± 24.4 sec; p=0.001)
Discussion: Our results demonstrate that the modified “2-in-1” femoral nerve block technique
provides effective sensory and motor block for femur surgery, regardless of BMI. Although we
achieved high success in both obese and non-obese patients, both block onset time and block
procedure time was significantly longer in the former group.
References:
1. Winnie AP, et al. Anesth. Analg. 1973; 52: 989-96
2. Marhofer P, et al. Anesth. Analg. 1997; 85: 854-7
3. Parkinson SK, et al. Anesth. Analg. 1989; 68: 243-8
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society.
Personal conflicts of interest: Nothing to disclose.
Figure: Ultrasound-guided femoral nerve block. Fascia lata and fascia iliaca are delineated. Needle
trajectory is indicated by the dashed line; green X's mark the injection points. FA, femoral artery; FN,
femoral nerve.
A35
INTERSCALENE NERVE BLOCK IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA
UNDERGOING AMBULATORY SHOULDER ARTHROSCOPY
D. Jackson, S. Orebaugh, M. Kentor, K. King, B. Williams
1
Department of Anesthesiology, Division of Acute Interventional Perioperative Pain Service, University
2
3
4
of Pittsburgh, UPMC Southside/Mercy Ambulatory Surgical Center, UPMC Passavant, Department
5
of Anesthesiology, University of Pittsburgh, Veterans Affairs Medical Center, Pittsburgh, PA, USA
Introduction: As shoulder arthroscopy has become a common ambulatory procedure, interscalene
1
block (ISB) has become an increasingly favored choice as its primary anesthetic. The ipsilateral
phrenic nerve palsy that often results from ISB may be particularly problematic in patients with
preexisting pulmonary disease, including obstructive sleep apnea (OSA). We sought to evaluate the
effects of an intermediate-duration mixture of local anesthetics in patients with OSA presenting for
ambulatory shoulder arthroscopy, with particular emphasis on pulmonary symptomatology and
oxygen saturation.
Materials and methods: This is a prospective, observational, multi-center study of patients
undergoing ambulatory shoulder arthroscopy who have known or suspected OSA based on prior
2
positive sleep study or high clinical suspicion according to ASA Practice Guidelines. ISB is performed
per our standard ultrasound-guided technique using 20 ml of a mixture of 1.6% mepivicaine and 0.2%
ropivicaine which we typically utilize for these patients. Patients then receive moderate sedation with
propofol and ketamine for the operative procedure. The patients are evaluated postoperatively in
Phase 1 and 2 recovery, as well as after discharge to assess block success, duration, and incidence
of adverse events. We also compared outcome variables for those with BMI above and below 35.
Results: Twenty-two patients have been enrolled. Block success has been 100%; no cases have
required conversion to general anesthesia. Mean (SD) block duration, defined as time until first pain,
is 10 hours and 52 minutes (6 hours and 10 minutes). No episodes of postoperative airway
obstruction or desaturation have occurred in Phase 1 or Phase 2 recovery. The mean SpO2 in Phase
2 recovery in the BMI < = 35 group was 97.2%, significantly higher than the mean value of 95.2% in
the BMI > 35 group (mean difference 2.00; 95% CI [0.33 - 3.67], P=0.02). There was no difference in
baseline mean SpO2 values between the groups (P=0.16). All patients were discharged home where
24% noted dyspnea, though all of these patients rated it as mild and not affecting their activities. No
patients required re-admission or emergency department visits for dyspnea.
Discussion: We have found that intermediate-duration ISB is a safe and effective means of providing
surgical anesthesia and postoperative analgesia in patients with OSA undergoing shoulder
arthroscopy in an ambulatory setting. Despite the block´s tendency to cause paralysis of the ipsilateral
hemidiaphragm, which may be more problematic in this patient population with preexisting respiratory
impairment, no adverse events have occurred. The formulation of local anesthetics utilized in these
patients is intended to limit block duration to the day of surgery, thereby avoiding the likelihood of
respiratory complications that may result from OSA along with a paretic diaphragm after patients
retire, while still providing a reasonable duration of analgesia.
References:
1. Memtsoudis SG, Kuo C, Ma Y, et al. Changes in Anesthesia-Related Factors in Ambulatory Knee
and Shoulder Surgery. Reg Anesth Pain Med. 2011;36:327-31.
2. ASA Task Force on Perioperative Management of Patients with OSA. Practice Guidelines for the
Perioperative Management of Patients with OSA. Anesthesiology. 2006;104:1081-93.
Funding: none
Conflicts of Interest: none
A36
ADDITION OF PERIPHERAL NERVE BLOCKADE TO GENERAL ANESTHESIA FOR TOTAL
SHOULDER ARTHROPLASTY - DO PERIOPERATIVE OUTCOMES DIFFER?
1
1,2
1,2
1
1
1
1
I. Kao , T. Danninger , O. Stundner , R. Rasul , Y.-L. Chiu , X. Sun , P. Fleischut , C.M.
3
1
1
Brummett , M. Mazumdar , S.G. Memtsoudis
1
Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell
2
University, New York, NY, USA, Department of Anesthesiology, Perioperative Medicine and Intensive
3
Care Medicine, Paracelsus Medical University, Salzburg, Austria, Division of Biostatistics and
4
Epidemiology, Department of Public Health, Weill Medical College of Cornell University, Department
of Anesthesiology, NewYork-Presbyterian Hospital, Weill Medical College of Cornell University, New
5
York, NY, Department of Anesthesiology, Division of Pain Medicine, University of Michigan Health
System, Ann Arbor, MI, USA
Introduction: Regional anesthesia has proven to be a highly effective technique for pain control after
total shoulder arthroplasty [1]. It remains largely unknown however, if the use of peripheral nerve
blocks can affect the rate and risk of systemic complications after surgery. Therefore, we chose a
population-based approach to examine the differential impact of general anesthesia with or without
addition of a peripheral nerve block in patients undergoing total shoulder arthroplasty.
Material and methods: In a discharge database containing data from approximately 400 US
hospitals (Premier Inc), we queried for all patients who underwent total shoulder arthroplasty under
general anesthesia between 2006 and 2010. Groups were established based on whether patients
received a peripheral nerve block in addition to general anesthesia, or general anesthesia only.
Groups were compared with regard to demographics, comorbidities and incidence of major
perioperative complications. Moreover, we performed a multivariate regression analysis in order to
assess the independent influence the addition of a nerve block to general anesthesia blocks exerts.
Results: We identified 17,157 patients that underwent total shoulder arthroplasty between 2006 and
2010. 19.3% received an upper extremity peripheral nerve block in addition to general anesthesia.
Patients receiving regional anesthesia were on average slightly younger (68.8 vs 69.4 years, P<
0.001), but had a similar comorbidity index (average Deyo index 0.91 vs 0.92, p< 0.001) and
comparable prevalence of individual comorbidities, compared to those patients that received general
anesthesia only. There was no relevant difference in the incidence of perioperative respiratory,
cardiac or other complications between the groups. In the multivariate regression analysis, the use of
general anesthesia with a peripheral nerve block versus general anesthesia only (referent) was not
associated with altered odds ratios (ORs) for: combined complications OR=1.06 (CI 0.93;1.21),
P=0.4053; cardiac complications OR=1.10 (CI 0.94;1.29), P=0.2441; respiratory complications
OR=0.96 (CI 0.70; 1.32), P=0.814; invasive ventilation OR=0.55 (CI 0.28;1.09), P=0.0855; transfusion
OR=0.93 (CI 0.78;1.12), P=0.4442; ICU admission OR=1.14 (CI 0.89;1.47), P=0.2988. However,
regional anesthesia was independently associated with a lower OR for length of hospital stay
th
exceeding the 75 percentile, compared to general anesthesia only (OR=0.87 (CI 0.79;0.96),
P=0.004).
Discussion: In this large cohort of patients receiving total shoulder arthroplasty, addition of an upper
extremity peripheral nerve block to general anesthesia was not associated with increased rates of or
odds for perioperative complications, postoperative mechanical ventilation, transfusion, or ICU
admission. However, patients receiving regional anesthesia were less likely to have increased length
of stay.
References: 1. Ilfeld BM et al. Ambulatory continuous interscalene nerve blocks decrease the time to
discharge readiness after total shoulder arthroplasty: a randomized, triple-masked, placebo-controlled
study. Anesthesiology. 2006 Nov;105(5):999-1007.
A37
PATIENT INVOLVEMENT IN SURGICAL SAFETY: A SURVEY OF PATIENT PERCEPTIONS AND
SATISFACTION DURING PRE-PROCEDURAL TIME-OUT PRIOR TO PERIPHERAL NERVE
BLOCKADE
Y. Lai, M.R. Anderson, H.M. Lin, A. Weinberg, M.A. Rosenblatt
Anesthesiology, Mount Sinai School of Medicine, New York, NY, USA
Background: Regional anesthetic procedures performed at the wrong site or on the wrong side can
be catastrophic for the patient, perioperative personnel, and the institution. Numerous organizations
proposed that having patients actively participate in the time-out process could be beneficial in
improving communication, however, the nature and extent of this participation or its impact on
preventing errors has not been determined. Moreover, there is no evidence showing how the
universal protocol influences patients' perception of their surgical and anesthetic experience. A root
cause analysis of wrong-site pain management injections suggests that lucid patients should not be
relied on as safeguards. Hence, we need to understand whether a patient-centered verification
process for peripheral nerve blockade is associated with enhanced perceptions of perioperative safety
and satisfaction.
Objectives: To survey patients on perceptions regarding their participation in a standardized time-out
process prior to receiving sedation for regional anesthesia.
Methods: After IRB approval, 189 orthopedic patients undergoing peripheral nerve blockade were
recruited over a 2-month period, and they participated in a standardized nerve block verification
process after baseline demographic information was collected. The regional anesthesia time-out
protocol involved a written script dictating verbal participation and confirmation between the nonpremedicated patient and anesthesiologists, which was witnessed by an independent healthcare
provider who is not involved in the care of the patient. A 10-item survey, with an additional narrative
question, using the symmetric six point Likert scale, was modified from the Iowa Satisfaction with
Anesthesia Scale (ISAS). A single investigator who was blinded to pre-procedural time out process
administered the questionaire postoperatively.
Results: Complete data were present for 175 patients who underwent blocks (55 interscalene, 62
supraclavicular, 5 infraclavicular, 22 femoral, 26 popliteal blocks, and 5 ankle). Survey items on
perception of confidence in their nerve block, sense of safety, and participant's level of relaxation
during time-out were grouped as primary composite outcomes. On a Likert scale ranging from -3 to
+3, 90% of patients reported scores of +3 for all primary composite outcomes. In addition, Pearson
correlation tests revealed that primary composite scores are associated with pre-procedural pain
scores and overall satisfaction perioperatively. No correlation exists between primary composite
outcomes and age, ASA status, and procedure type. On another survey item, 97% of patients
expressed that they would not alter their involvements in the time out protocol. Lastly, 93% of
participants reported high satisfaction associated with their anesthesia experience. . The survey was
tested for reproducibility resulting in an 88% correlation over a 2-week period.
Discussion: This study demonstrates enhanced perceptions of confidence in anesthesia providers
and overall safety regarding their anesthetic care when lucid patients are allowed to participate in the
pre-procedural time out process. In addition, there is no evidence to suggest that this verification
process increases patient anxiety. Further studies will be needed to assess the actual impact this
intervention has on preventing wrong side anesthetic blocks or surgery.
References: Cohen, SP, et al. Incidence and root cause analysis of wrong-site pain management
procedures: a multicenter study. Anesthesiology. 2010.Mar;112(3):711-8.
Funding: Institutional.
A38
THE IMPACT OF NEURAXIAL ANESTHESIA ON DISTAL AND PROXIMAL TISSUE PERFUSION A PILOT STUDY
1
1,2
1,2
1
1
1
1
1
S.G. Memtsoudis , O. Stundner , T. Danninger , Y. Ma , J. Bae , D. Yoo , I. Kao , D. Maalouf , A.
1
1
3
3
Gonzalez Della Valle , T.P. Sculco , S.O. Heard , J.M. Walz
1
Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell
2
University, New York, NY, USA, Department of Anesthesiology, Perioperative Medicine and Intensive
3
Care Medicine, Paracelsus Medical University, Salzburg, Austria, Division of Biostatistics and
4
Epidemiology, Department of Public Health, Weill Medical College of Cornell University, Department
of Orthopedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, New
5
York, NY, Department of Anesthesiology, University of Massachusetts Medical School, Worcester,
MA, USA
Introduction: Hypotensive epidural anesthesia (HEA) has proven effective in reducing blood loss and
can serve as part of a multimodal approach for prophylaxis of thromboembolism in patients
undergoing total hip arthroplasty (THA) [1]. However, little data exists to detail the effect of this
technique on differential perfusion changes above and below the level of neuraxial blockade. This
study was designed to elucidate changes in this parameter in a clinical setting, using non-invasive
near-infrared spectroscopy (NIRS) [2, 3].
Material and methods: Patients aged 18 to 85 undergoing primary total hip arthroplasty under HEA
(as per institutional protocol [4]) were enrolled. Data on patient demographics (age, gender, ethnicity,
comorbidities) and intraoperative data (fluid balance, duration of surgery) were recorded. Muscle
oxygenation was measured by continuous sampling of NIRS spectra at two standardized locations
above and below the level of neuraxial blockade (deltoid and quadriceps femoris muscles) using two
CareGuide™ NIRS devices (Reflectance Medical, Westborough, MA). Stroke volume (SV) and
cardiac output (CO) were recorded continuously using a validated non-invasive bioreactance monitor
(NICOM™; Cheetah Medical, Vancouver, WA). Other continuously recorded parameters included
heart rate (HR), invasive mean arterial blood pressure (MAP) and arterial oxygen saturation.
Recordings of muscle oxygenation were compared over time and correlated with other cardiovascular
parameters, separately for upper and lower extremity. For the longitudinal analysis the generalized
estimating equations (GEE) method was used, controlling for age, body mass index and gender.
Results: 10 patients undergoing THA under HEA were enrolled (mean age 60.3 years (SD 9.9),
2
mean BMI 26.2 kg/m (SD 5.4); mean surgical time 83.0min (SD 19.7)). Figure 1 displays mean
oxygenation levels of the deltoid (blue line) and quadriceps (red line) muscles, representing perfusion
status above and below the neuraxial block, respectively. While oxygenation in the deltoid muscle did
not change significantly between the individual time points, longitudinal analysis of oxygenation levels
in the quadriceps revealed a intermittent decline and significant difference between and across all
time points (p< 0.0001). Figure 2 displays other hemodynamic parameters. While MAP reveals a
decrease characteristic for hypotensive epidural anesthesia (pre-surgical baseline: 65.5mmHg (SD
24.5), nadir: 56.6mmHg (SD 11.9), surgery end: 66.1mmHg (SD 22.9)), HR and CO increased
significantly over time (HR: 66 vs 74 bpm, p< 0.0001; CO: 3.5 vs 4.0 L/min; p< 0.0001).
[Figure 1 - Muscle Oxygenation (SmO2)]
[Figure 2 - Hemodynamic Parameters]
Discussion: These preliminary results indicate that muscle oxygenation, a surrogate parameter for
tissue perfusion, is significantly altered by HEA, but only within the functional limits of neuraxial
blockade. Despite low systemic blood pressure, oxygenation remained unchanged in the upper
extremity. In a next step, we plan to analyze relationships between other cardiovascular parameters
and muscle oxygenation. A control group consisting of patients undergoing normotensive epidural
anesthesia will be added.
References:
1) González Della Valle A et al. Clin Orthop Relat Res. 2006
2) Treschan et al. Anesth Analg. 2003
3) Soller et al. J Appl Physiol. 2008
4) Sharrock NE et al. Acta Orthop Scand. 1996
A39
SENSORY AND MOTOR EFFECTS OF MID-THIGH ADDUCTOR CANAL BLOCK
H. Murgatroyd, P. Cholvisudhi, V. Chan, A. Perlas, K. Arkadiy, K.J. Chin
Department of Anesthesiology, Toronto Western Hospital, University of Toronto, Toronto, ON,
Canada
Introduction: The sub-sartorial adductor canal block is an alternative analgesic technique to femoral
nerve block in major knee surgery. A potential advantage is sparing of quadriceps weakness, allowing
earlier patient mobilization. [1, 2] However, the dose of local anesthetic required for optimum
analgesia has not been determined. This prospective pilot study aimed to determine the extent of
sensory and motor effects of adductor canal blockade performed with 20 ml of Ropivacaine 0.5% with
1:400,000 epinephrine.
Materials and methods: Following Research Ethics Board approval, nine patients undergoing
elective total knee arthroplasty received a mid-thigh ultrasound-guided adductor canal block. Sensory
blockade was measured by tolerance to increasing current of Transcutaneous Electrical Stimulation
(TES) in four quadrants surrounding the patella, up to a maximum tetanic stimulus of 60 mA at 50 Hz
for 5 seconds (considered equivalent to surgical anesthesia [3]). Pinprick sensation mapping was
performed 30 minutes after block completion. Motor blockade of the quadriceps was measured by
isometric force dynamometer every 10 minutes for up to 40 minutes following the block.
Results: Surface analgesia to pinprick sensation:
Data was available for 8 out of 9 patients. A consistent area of analgesia covering all four quadrants
of the anterior aspect of the knee from above the patella to the tibial tuberosity was obtained in all
eight patients (Figure 1). Surface analgesia extended distal to the tibial tuberosity in 4 patients.
[Figure 1: Loss of pinprick sensation.]
Transcutaneous Electrical Stimulation:
There was a trend towards an increase in tolerance to 1 Hz TES over time. (Figure 2) Four out of nine
patients developed tolerance to 50 Hz TES, but no patient was able to tolerate TES equivalent to
surgical stimulus.
[Figure 2: Tolerance to TES]
Quadriceps strength:
There was no reduction in quadriceps strength at 20 minutes following the block. There was, in fact, a
non-significant increase in median quadriceps strength from 20 (IQR: 19 - 23) to 22 (IQR: 15-25)
pounds of force.
Discussion: Adductor canal blockade with 20 ml of 0.5% Ropivacaine appears to consistently
produce surface analgesia over all four anterior quadrants of the knee, whilst preserving quadriceps
motor power. No patients were able to tolerate 60 mA of tetanic stimulation for 5 seconds [3], which
suggests that this dose does not produce surgical anesthesia.
References:
1. Lund J, et al. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after
major knee surgery: preliminary results. Acta Anaesthesiol Scand 2011; 55(1): 14-9.
2. Manickam B, et al. Feasibility and efficacy of ultrasound-guided block of the saphenous nerve in
the adductor canal. Reg Anesth Pain Med 2009; 34(6): 578-80.
3. Chiu AA, et al. The effects of epinephrine on lidocaine spinal anesthesia: a cross-over study.
Anesth Analg 1995; 80(4): 735-9.
Funding disclosure:Study was funded from the departmental budget.
Personal conflicts of interest disclosure:Nothing to disclose
A40
REPRODUCIBILITY OF SENSORY THRESHOLD CURRENT FOR THE NEUROMETER AND A
PERIPHERAL NERVE STIMULATOR IN HEALTHY VOLUNTEERS
T.J. Shakespeare, B.C.H. Tsui, D.H. Leung, J.H. Tsui, G.N. Corry, Edmonton Academy of Regional
Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Current methods of assessing nerve blocks, such as loss of perception to cold
sensation, are subjective at best. Transcutaneous nerve stimulation has previously been used to
1-3
measure current perception threshold (CPT) in individuals with neuropathic conditions.
Various
2;4
commercially available devices, such as the Neurometer, allow one to measure CPT and may be
useful as a tool for assessing peripheral nerve blocks. Here, we have tested the ability of the
Neurometer and a common peripheral nerve stimulator to provide reproducible CPT readings on
healthy volunteers.
Material and methods: We recruited ten volunteers to examine CPT reproducibility using the
Neurometer (Neurotron, Inc., Baltimore, MD, USA) and the StimPod NMS450 peripheral nerve
stimulator (Xavant Technology, Pretoria, South Africa) (Figure 1).
[Figure 1]
Subjects' CPT was determined for the median (second digit) and ulnar (fifth digit) nerve sensory
distributions of both hands at 5 Hz, 250 Hz, and 2000 Hz with the Neurometer and at pulse widths of
0.1 ms, 0.3 ms, 0.5 ms, and 1.0 ms, both at 5 Hz and 2 Hz, using the StimPod. Intraclass correlation
coefficients (ICC) were calculated to assess reproducibility; ICC values < 0.4 are considered poor,
5
values between 0.4 and 0.75 are considered good, and values ≥ 0.75 are excellent.
Results: Six male and four female volunteers were recruited for the study; no subjects withdrew due
to test discomfort. During the study, sensory perception with the Neurometer was reported by most
volunteers as “tingling,” while the StimPod stimulus was reported as “tapping.” All of the ICC values
fell within the good and excellent ranges for reproducibility except those of the Neurometer at 5 Hz
(second digit, 0.292; fifth digit, 0.318) (Figure 2).
[Figure 2]
Discussion: The StimPod peripheral nerve stimulator displayed acceptable reproducibility in
measuring CPT in healthy volunteers, whereas at a similar low frequency, the Neurometer's
reproducibility fell outside the acceptable limit. These results suggest that peripheral nerve stimulators
may be useful devices for measuring CPT to assess nerve blocks.
References:
1. Katims et al. J.Occup.Med. 1986; 28: 1219-21
2. Masson EA et al. Diabetologia 1989; 32: 724-8
3. Matsumoto R et al. J.Int.Med.Res. 2005; 33: 442-53
4. Masson EA et al. Diabet.Med. 1991; 8: S63-S66
5. The design and analysis of clinical experiments. New York, Wiley, 1986.
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society. Partial funding for this study was provided by from the
Department of Anesthesiology and Pain Medicine.
Personal conflicts of interest: Nothing to disclose.
Figure 1. Setup of current perception threshold testing equipment. Shown are the Neurometer,
StimPod NMS450, switch box, and subject with stimulating and ground electrodes attached.
Figure 2. Reproducibility of the Neurometer and StimPod at each setting for the second digit (A) and
fifth digit (B). Reproducibility is represented by ICC (filled circles); bars indicate 95% confidence
intervals.
A41
HANDS-ON GEL PHANTOM AND INSTRUCTIONAL VIDEO TRAINING IMPROVE
SONOANATOMY KNOWLEDGE: A RANDOMIZED CONTROLLED TRIAL
1
1
1
2
B.A. VanderWielen , R. Harris , R.E. Galgon , L.M. VanderWielen , K.M. Schroeder
1
1
2
University of Wisconsin, Department of Anesthesiology, University of Wisconsin, Madison, WI,
Department of Health Administration, Virginia Commonwealth University, Richmond, VA, USA
3
Introduction: Millions of patients worldwide annually receive neuraxial anesthesia. Obesity,
pregnancy, and abnormal spinal anatomy pose challenges for accurate landmark palpation.
1,2
Ultrasound can be utilized to identify relevant structures and decrease procedural complications.
3
Gel phantom models and instructional videos are low-cost ultrasound teaching tools, but literature on
their effectiveness remains limited. This study evaluated hands-on gel phantom and instructional
video training for teaching spinal sonoanatomy amongst anesthesiology faculty and residents.
Materials and methods: Following IRB approval, 23 residents and 27 anesthesiologists, randomized
to gel phantom, video teaching, and control groups participated.
Gel Phantom
Video Training
Control
Overall Residents Faculty Overall Residents Faculty Overall Residents Faculty
(n=17)
(n=8)
(n=9) (n=18)
(n=8)
(n=10) (n=15)
(n=7)
(n=8)
38.47
(12.59)
28.50
(1.51)
47.33 37.00
(10.34) (7.55)
30.88
(1.89)
41.90
(6.71)
43.73
(13.81)
31.86
(4.49)
54.13
(9.98)
Anesthesiology
9.47
Experience, yrs (Mean,
(10.96)
SD)
1.75
(0.89)
16.33 7.44
(11.27) (7.41)
2.00
(0.76)
11.80
(7.48)
15.07
(14.65)
2.57
(0.53)
26.00
(11.66)
Spine Anatomy
Analysis Experience
(%)
17.6
25
11.1
11.1
12.5
10
0
0
0
Epidrual/Spinal/Lumbar
Puncture Experience
17.6
(%)
25
11.1
5.5
12.5
0
0
0
0
Peripheral Nerve
Blockade Experience
(%)
64.7
50
77.8
50
75
30
73.3
100
50
Vascular Access
Experience (%)
100
100
100
100
100
100
80
100
62.5
Age, yrs (Mean, SD)
[Group Demographics]
A lumbar spine gel phantom model and an instructional video were created and used to teach
sonoanatomy (lamina and spinous and transverse process) identification.
[Spine sonoanatomy]
All participants attempted ultrasound identification of these structures on a human volunteer, both
immediately and three weeks later. Perceived knowledge and training modality satisfaction
(intervention groups) were assessed using modified Likert scales.
Results: Both interventions improved spine sonoanatomy identification accuracy compared to the
control group immediately following training, but not at follow-up.
Gel Phatom
Baseline
Teaching Video
Three-week
Retention
Baseline
Three-week
Retention
Control
Baseline
Three-week
Retention
Spinous
process (%)
100.00
93.3
100.0
100.0
86.7
100.0
Lamina (%)
88.2
66.6
72.2
47.5
40.0
50.0
Transverse
Process (%)
76.5
13.3
77.8
17.6
33.3
33.3
[Performance of Spinal Sonoanatomy Identification]
Logistic regression analysis, controlling for faculty status, age, and anesthesia and ultrasound
experience, demonstrated both interventions improved the odds of transverse process (gel 12.61, p =
0.013; video 7.93, p = 0.030) and lamina (gel 65.12, p = 0.003; video 8.97, p = 0.031) identification.
Perceived knowledge of basic spinal anatomy and spinal sonoanatomy improved in the intervention
versus control groups.
[Perception of spine sonoanatomy knowledge]
Intervention group participants rated both teaching modalities as highly satisfactory. Mean (SD)
modified Likert scale scores (1=“unsatisfied”, 10=“very satisfied“) were 8.12(1.50) and 8(1.68) for
hands-on gel phantom and instructional video training participants, respectively.
Discussion: Use of either hands-on gel phantom or instructional video training can improve
anesthesia staff and resident knowledge of lumbar spine sonoanatomy. Identifying these structures
may improve neuraxial anesthesia placement. Future studies are necessary to assess training
modality effects on performance benefits in obese patient populations and those with abnormal spine
anatomy.
References:
1.Chin et al, Anesthesiology 2011; 115:94-101
2.Grau et al, Reg Anesth Pain Med 2001; 26:64-67
3.Li et al, J Ultrasound Med 2011; 30:263-272.
Funding Support: Department of Anesthesiology, University of Wisconsin School of Medicine and
Public Health
Authors have no disclosures.
A42
ULTRASOUND GUIDED TRANSVERSUS ABDOMINIS PLANE (TAP) BLOCK AS UNIQUE
ANALGESIC FOR CESAREAN SECTION
J.S. Vilchis Rentería, M.D. González Guzmán, A.M. Romero González, A.F. Cuéllar Lopez
Hospital Materno Infantil de Alta Especialidad, Guadalupe, Mexico
Introduction: The standard multimodal analgesic for cesarean section is the epidural morphine; the
ultrasound guided transversus abdominis plane (TAP) block, which entirely blocks the sensory
innervation of the anterior abdominal wall, also eliminates the undesirable effects of morphine and
provides a satisfactory managed postoperative analgesia in multimodal regimes. We assess the
analgesic efficacy of TAP block up to 8 days of the postoperative period as unique analgesic,
compared with morphine epidural for the cesarean delivery.
Methods: A prospective, randomized study, prior informed consent and Institutional Review Board
approval, was made in 40 healthy patients with term pregnancy scheduled for elective cesarean
section, divided into two groups: Morphine Group (n = 20) and TAP Group (n = 20). All patients
received epidural block with 400 mgs. of 2% lidocaine plus epinephrine 1:200,000. At the end of the
surgery, morphine group were administered 1.5 mgs. of epidural morphine; in TAP group was
performed bilaterally ultrasound guided TAP block with 75 mgs. of ropivacaine at 0.325% (20 ml
volume) on each side. The intensity of pain was evaluated at 4, 12, 24, 48 hours and 8 days of the
postoperative using Visual Analog Scale (VAS). The Wilcoxon test and the Pearson coefficient for
study of correlations were chosen for the validation of comparisons.
Results: Demographic parameters were homogeneous in both groups. On measurements of pain
post operative VAS average were lower than 3 in both groups, without a statistically significant
difference. The average of VAS was greater in the group of epidural morphine: 2.7, and 0.95 in the
transverse plane block group at 48 hours (P = 0. 002). The 4 hrs., 12 hrs., 24 hrs. and 8 days
averages of VAS did not increase in the TAP group, reported no significant differences (P > 0.05);
while in the morphine group was presented a slight increase in the scale of VAS at the 24 hrs.,
although without being significant.
Discussion: The use of the ultrasound guided TAP block for postoperative analgesia in cesarean
section offers an adequate pain control, keeping average of EVA low with the passage of time from 48
hours up to 8 days compared to the use of epidural morphine postoperative.
[VAS BY MEASURING TIME]
References:
1. McDonnell J.G., Curley G., Carney J., Benton A., Costello J. The analgesic efficacy of transversus
abdominis plane block after cesarean delivery: a randomized controlled trial. Anesth Analg. 2008;
106: 186-91.
2. Kanazi G.E., Aouad M.T., Abdallah F.W., Khatib M.I., Adham A.M. Harfoush D.W. The analgesic
efficacy of subarachnoid morphine in comparison with ultrasound-guided transversus abdominis plane
block after cesarean delivery: a randomized controlled trial. Anesth Analg. 2010; 111: 475-481.
3. Belavy D., Cowlishaw P.J., Howes M., Phillips F. Ultrasound guided transversus abdomins plane
block for analgesia after caesarean delivery. Br J Anaesth. 2010; 103(5): 726-730.
Personal funding made the present work and there is nothing to disclose.
A43
SCIATIC NERVE BLOCK BENEFICIAL WHEN COMBINED WITH FEMORAL NERVE BLOCK FOR
TOTAL KNEE ARTHROPLASTY
1
2
1
1
D. Dillane , D. Sriramatr , S. Rashiq , B. Tsui
1
2
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada, Anesthesiology,
Srinakharinwirot University, Bangkok, Thailand
Current best evidence indicates that single shot femoral nerve blockade as part of a multimodal
regime is the most appropriate way of managing pain after total knee arthroplasty(1). There is not
enough evidence to recommend adding a sciatic nerve block to a single-shot femoral nerve block.
Continuous femoral nerve blockade cannot be recommended based on current evidence. In this study
we retrospectively reviewed the medical records of all patients who underwent TKA at our institution
over a 5 year period when analgesia after TKA transitioned from parenteral opioids to peripheral
nerve blockade. We specifically investigated the efficacy of the principal means of analgesia and its
effect on length of stay.
Research Ethics Committee approval was obtained. Recorded variables included age, gender, length
of stay, administration of femoral and sciatic nerve block, patient controlled analgesia (PCA) use and
Visual Analogue Pain (VAS) scores on Days 0 - 2. Length of stay and VAS scores were compared
between groups using ANOVA, followed by Tukey's post hoc test for intergroup differences.
The medical records of 983 patients who underwent TKA during the study period were examined
(Table 1). All regional techniques had significantly better VAS scores on Day 0 when compared with
no block (Figure 1). Addition of a single shot sciatic block to a femoral catheter technique significantly
improved VAS score on Day 0 when compared with femoral catheter technique alone. Femoral
catheter with or without a single shot sciatic block was associated with significantly lower VAS scores
when compared with single shot femoral blocks on Day 1. This improvement did not persist to Day 2.
A single shot femoral block significantly reduced length of stay by 1 day when compared with no block
(Figure 2). A combined femoral catheter and single shot sciatic technique significantly reduced length
of stay by 1.5 days when compared with no block.
This study shows the analgesic benefit at Day 0 of adding a single shot sciatic block to a continuous
femoral technique. Even though LOS was reduced by 1.5 days when a combined femoral / sciatic
technique is compared with no block, this does not compare favorably with the currently reported LOS
mean of 3 - 4 days (2). This may be due to a large dose of highly concentrated local anesthetic
contributing to post-operative quadriceps weakness and delayed rehabilitation. More active
management of a continuous femoral catheter technique may preserve its significant effect on postoperative pain while leading to a further reduction in LOS.
1. Paul JE et al. Anesthesiology. Nov;113(5):1144-62.
2. Salinas FV et al. Anesth Analg. 2006 Apr;102(4):1234-9
No Sciatic Block
Single-Shot Sciatic
Block
Total
No Femoral Block
565
0
565 (58%)
Single-Shot Femoral
Block
123
15
138 (14%)
Femoral Catheter
75
205
280 (29%)
Total
763 (78%)
220 (22%)
983 (100%)
[Table 1. Number of Patients By Block Type]
[Figure 1. Mean VAS Scores on Day 0, 1 and 2]
[Figure 2. Mean Length of Stay (Days)]
A44
BODY MASS INDEX (BMI) DOES NOT AFFECT TIME TAKEN OR SUCCESS RATE WHEN
SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK IS PERFORMED WITH ULTRASOUND
GUIDANCE
1
2
1
1
D. Dillane , D. Sriramatr , S. Rashiq , B. Tsui
1
2
University of Alberta, Edmonton, AB, Canada, Anesthesiology, Srinakharinwirot University,
3
Bangkok, Thailand, Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Regional anesthesia in the obese patient can be challenging. A retrospective analysis of 2020 nerve
stimulator guided supraclavicular blocks demonstrated that obesity was associated with a decrease in
success rate and an increase in relative difficulty (1). Schwemmer did not find a significant difference
in success rates for ultrasound guided interscalene blockade (2). In this retrospective study we
reviewed data from our acute pain database from the past year. All patients who underwent
ultrasound + nerve stimulation guided supraclavicular brachial plexus blocks for hand surgery were
included to determine if BMI was associated with time taken or success rate.
Research Ethics Committee approval was obtained. Variables included age, gender, height, weight,
practitioner grade, time to perform the pre-block scan and the block, volume of local anesthetic
mixture, necessity for, timing of and type of supplemental blockade and the necessity for general
anesthesia. Block failure was defined as necessity for general anesthesia or any supplemental nerve
blockade following the supraclavicular block.
135 patients were reviewed (Table 1). There was no correlation between BMI and block/scan time,
adjusted for practitioner grade (Pearson's r=0.09, p=0.27). We modeled block failure as composite
binary outcome using logistic regression. Indicator variables were created for BMI < 25, BMI 25 to <
30 and BMI ≥ 30. Staff anesthesiologist performance was used as the reference category for
practitioner grade. Gender was also included. The model's c statistic was 0.726 (Table 2).
BMI did not appear to influence block performance time or failure rate when ultrasound was combined
with nerve stimulation. Block success rates were not influenced by practitioner grade. This may have
been a selection effect. Female gender was associated with higher block success. Further analysis
revealed that females received 16% more local anesthetic per kilogram (p=0.0058) which may explain
this unexpected finding.
Age (mean±SD)
36±16
Gender (M:F)
112:23
Weight (Kg, Mean ±SD)
84±20
BMI (Kg/m2 Mean±SD min-max
27.5±5.6 15.1 - 46.7
Number of Staff
21
Number of Fellows
46
Number of Residents
68
Pre-block scan time (mins:mean, min-max) 1.3, 0 - 9
Block time (mins:mean, min-max)
4.7, 2 - 15
Total time (mins:mean, min-max)
6.0, 3 - 6
[Table 1. Clinical characteristics of sample n= 135]
Odds of block failure
95% C.I. (Lower)
95% C.I. (Upper)
P value
Male Gender
Reference
Reference
Reference
Reference
Female Gender
0.08
0.01
0.63
0.017
Staff anesthesiologist
Reference
Reference
Reference
Reference
Fellow
1.35
0.44
4.11
0.602
Resident
0.45
0.15
1.35
0.155
BMI < 25
Reference
Reference
Reference
Reference
BMI 25 - 30
1.21
0.47
3.10
0.692
BMI > 30
1.74
0.64
4.73
0.278
[Table 2. Results of logistic regression model]
1. Franco CD. Anesth Analg. 2006 Apr;102(4).
2. Schwemmer U. Ultraschall Med. 2006 Jun;27(3).
A45
INJECTION PRESSURE MONITORING RELIABLY DETECTS NEEDLE-NERVE CONTACT
DURING ULTRASOUND-GUIDED INTERSCALENE BRACHIAL PLEXUS BLOCK
J. Gadsden, J. Choi, E. Lin, A. Robinson, A. Shariat
Anesthesiology, St. Luke's-Roosevelt Hospital Center, New York, NY, USA
Introduction: While US guidance during peripheral nerve blockade (PNB) has improved success
1
rate, neurologic complications continue to occur. Needle-nerve contact and/or intraneural injection
2,3
during PNBs have been shown to lead to nerve inflammation and/or injury. The objective of this
study is to evaluate the utility of injection pressure monitoring as a useful adjunct for detecting needlenerve contact.
Methods: Following IRB approval and informed consent, 7 adult patients (with BMI < 35 and
adequate sono-anatomy) scheduled for shoulder surgery under interscalene block (ISB) were
recruited for this ongoing study. Under ultrasound guidance, a 22 G stimulating needle was
sequentially placed in three locations (1 mm from the trunk, needle-trunk contact, and disengagement
of needle-trunk contact to 1 mm), Figures 1 & 2.
[Figure 1]
[Figure 2]
At each location, the current (0.1 msec, 2 Hz) required to maintain motor response and the opening
injection pressure (OIP) required to initiate an injection of 1 mL D5W were recorded using an in-line
manometer (PendoTECH, Princeton, NJ) coupled to a computer via an analog-to-digital conversion
board (PressureMAT, PendoTECH, Princeton, NJ) and to a disposable injection pressure monitor
(BSmart, Concert Medical, Norwell, MA). Injectate was administered via an automated infusion pump
(PHD 2000, Harvard Apparatus, Holliston, MA) at 10 ml/min. Blinded investigators performed
evaluations and aborted injections when an opening injection pressure of 15 psi was reached.
Results: Minimum current required to maintain motor response varied widely and overlapped
between needle placements 1 mm from the nerve trunk (0.3-3.5 mA) and needle placements
contacting the nerve trunk (0.1-1.9 mA). Overall, a current of 0.5 mA detected needle-nerve contact in
6 of 7 (86%) patients and paresthesia occurred in 2 of 7 (28%) patients, whereas opening injection
pressure ≥15 psi detected all (100%) needle-nerve contacts.
Discussion: While electrical current (0.5 mA) detected needle-nerve contact in 86%, and paresthesia
in 28%, injection pressure monitoring (≥15 psi) detected all occurrences of needle-nerve contact. In
conclusion, the combination of US, nerve stimulation, and injection pressure monitoring detected
needle nerve contact and prevented injection against the nerve in all occurrences of needle-nerve
contact during ISB.
References:
1. Cohen JM, Gray AT. Functional deficits after intraneural injection during interscalene block. Reg
Anesth Pain Med 2010;35:397-9
2. Lupu CM, Kiehl TR, Chan VWS, El-Beheiry H, Madden M, Brull R. Nerve expansion seen on
ultrasound predicts histologic but not functional nerve injury after intraneural injection in pigs. Reg
Anesth Pain Med 2010;35:132-9
3. Steinfeldt T, Graf J, Schneider J, Nimphius W, Weihe E, Borgeat A, Wulf H, Wiesmann T.
Histological consequences of needle-nerve contact following nerve stimulation in a pig model.
Anesthesiol Res Pract 2011; epub April 19 2011
Funding: Departmental.
A46
DURATION OF ANALGESIC EFFECTIVENESS OF THE POSTERIOR AND LATERAL TAP
BLOCK TECHNIQUES FOR TRANSVERSE LOWER ABDOMINAL INCISIONS: A METAANALYSIS
F.W. Abdallah, J.G. Laffey, S.H. Halpern, R. Brull
Anesthesiology, University of Toronto, Toronto, ON, Canada
Background: Both the posterior (triangle of Petit) and lateral (mid-axillary line) approaches to the
transversus abdominis plane (TAP) block, provide effective early (0-12 hours) postoperative analgesia
1
following surgery involving a transverse incision. However, whether the posterior or lateral TAP block
can produce prolonged analgesia lasting beyond the first postsurgical 12 hours remains
2
controversial. This meta-analysis examines the duration of analgesia associated with each of the
posterior and lateral TAP block approaches in the first 48 hours following surgery using a lower
abdominal transverse incision.
Methods: We searched MEDLINE; Embase; Cochrane Database of Systematic Reviews; and
Cochrane Central Register of Controlled Trials databases for randomized controlled trials (RCTs)
investigating the analgesic effects of TAP block compared to placebo or systemic analgesia (control
group) in patients undergoing abdominal surgery using a lower abdominal transverse incision.
Outcomes sought included interval postoperative intravenous morphine consumption as well as rest
and dynamic pain scores at 12, 24, 36, and 48 h postoperatively. We also assessed the opioid-related
side effects and patient satisfaction at 24 and 48 h. The 12-24 h interval postoperative morphine
consumption was designated as our primary outcome. Random effects modeling was used to
combine the results.
Results: Twelve RCTs including a total of 641 patients were analyzed. Four of the trials examined the
posterior technique, and eight assessed the lateral technique. Compared to the control group, the
posterior TAP block reduced postoperative intravenous morphine consumption during the 12-24 and
24-48h intervals by 11.3 mg (95% CI: -16.61, -5.89; P< 0.0001) and 5 mg (95% CI: -9.54, -0.52;
P=0.03), respectively (Figure 1); reduced rest pain scores at 24, 36, and 48 h by 13 mm (95% CI: 21.7, -3.8; P=0.005), 18 mm (95% CI: -22.7, -12.9; P< 0.00001) and 15 mm (95% CI: -20.2, -8.9; P<
0.00001), respectively (Figure 2). The posterior TAP block reduced dynamic pain scores at 12, 24, 36
and 48 h by 16 mm (95%CI: -18.8, -13.0; P< 0.00001), 22 mm (95% CI: -32.8, -11.0; P< 0.0001), 12
mm (95% CI: -18.7, -5.2; P=0.0006), and 22 mm (95% CI: -33.2, -11.2; P< 0.0001), respectively; and,
reduced the incidence of sedation at 24 and 48 h by 59.5% (95% CI: 0.10, 0.57; P=0.001) and 100%
(95% CI: 0.00, 0.63; P=0.02), respectively. In contrast, the lateral TAP block did not reduce morphine
consumption, rest or movement pain scores or sedation scores compared to control groups at any of
these time points.
Conclusion: Based on the comparison of both techniques to control, the duration of analgesia
following the posterior TAP block for abdominal surgery via a lower abdominal transverse incision is
greater than the lateral TAP block. These findings may be partially explained by a retrograde
paravertebral spread of local anesthetics reaching the thoracolumbar sympathetic chain.
[Figure 1: Forest plots of morphine consumption for]
[Figure 2: Rest pain at A, 24 h. B, 36 h. C, 48 h.]
A47
SUCCESS RATE OF PERINEURAL INFRA-CLAVICULAR BRACHIAL PLEXUS CATHETERS:
RANDOMIZED CONTROLLED SINGLE BLIND TRIAL COMPARING PERIPHERAL NERVE
STIMULATION WITH ULTRASOUND GUIDED CATHETER PLACEMENT
S. Dhir, S. Ganapathy
Anesthesia and Perioperative Medicine, Western University, London, ON, Canada
Introduction and objectives: Peripheral nerve stimulation (PNS) and ultrasound-guided placement
techniques have been described for infraclavicular brachial plexus perineural catheters(1, 2). We
tested the hypothesis that US guided catheters produce better block success. The secondary
hypothesis was that infraclavicular catheters placed using only ultrasound guidance require less time
for placement when compared with catheters placed using only PNS.
Materials and methods: A total of 210 patients undergoing elective hand or elbow surgery were
randomly allocated to receive continuous infraclavicular brachial plexus block using ultrasound guided
needle and catheter placement (group US, n=105) or PNS guided stimulating needle and catheter
placement (group ST, n=105). Posterior cord stimulation was considered to be an end point in ST
group whereas spread of drug in the posterior cord location as observed by ultrasound imaging was
an end point in US group. All drug was administered through the catheter in both groups. Motor and
sensory blocks were assessed every 5 min and block success was determined at 30 min.
Complications and need for intraoperative supplements were noted. Primary outcome was block
success at the end of 30 minutes. during the surgery. The secondary outcomes were block success
for surgery, intraoperative analgesia requirement and the catheter insertion duration (minutes) starting
when the needle entered the patient skin and ending when the drug injection via the placed catheter
ended.
Results and discussion: Due to protocol violations, 8 patients were not included in analysis.
Catheters placed with ultrasound guidance took a significantly shorter time (mean 7.0 (±2.5) minutes
compared with 10.5 (±3.6) minutes for stimulation (P < .01). In 5 patients of US group and 16 in ST
group, we were unable to establish a complete block and this was statistically significant (p< .001). On
sub group analysis, all successful blocks in ST group had a posterior cord twitch elicited from needle
or catheter or both versus lateral cord in those that were unsuccessful. In three patient from ST group,
the catheter had to be placed with US guidance as no twitches could be elicited. One patient from ST
group had vascular puncture leading to hematoma formation. This block was successfully done with
US guidance. There was no difference in procedure-related pain scores and satisfaction.
Conclusions: In this prospective randomized controlled single blind trial, we found that placement of
infraclavicular perineural catheters is more successful with ultrasound guidance and takes less time.
Interestingly, we found out that if PNS stimulation is used for guidance and posterior cord twitch is
elicited via the stimulating catheter, there is no difference in block success rate.
References:
1. Mariano ER et al. Ultrasound Guidance Versus Electrical Stimulation for Infraclavicular Brachial
Plexus Perineural Catheter Insertion. J Ultrasound Med 2009; 28:1211-1218.
2. Slater ME, Williams SR, Harris P, et al. Preliminary evaluation of infraclavicular catheters inserted
using ultrasound guidance: through-the-catheter anesthesia is not inferior to through-the-needle
blocks. Reg Anesth Pain Med 2007; 32:296-302.
Funding: The entire project was funded by Physicians Services Incorporated Foundation, Canada.
A48
THE ROLE OF THE SAPHENOUS NERVE IN DISTAL TIBIA AND MEDIAL ANKLE JOINT
CAPSULE INNERVATION: A CADAVER STUDY
J.-L. Horn, N. Eglitis, S. Nelsen
1
2
Anesthesiology and Perioperative Medicine, Integrative Biosciences Department, Oregon Health
and Science University, Portland, OR, USA
Introduction: The saphenous nerve provides cutaneous innervation to the skin and soft tissues
1
overlying the medial and anterior lower leg . Our clinical experience suggests that adding a
saphenous nerve block to a sciatic nerve block is necessary to obtain complete anesthesia and/or
analgesia of the ankle even when the overlying skin remains undisturbed. The goal of this study is to
determine the role of the saphenous nerve in the innervation of the distal tibia and the medial ankle
joint capsule.
Material and methods: This study was approved by the OHSU institution review board. Twenty-five
lower legs from thirteen embalmed cadavers were dissected. The cadavers were between the ages of
59-100; five were male and eight were female. Each lower leg was opened with a superficial skin flap
extending distally from the lateral border of the proximal tibia to the dorsum of the foot and then
reflected medially to expose the medial and anterior portions of the lower leg. The saphenous vein
was identified along with the accompanying nerve. The nerve was then followed along its distal
course and branches deep to the subcutaneous tissue were identified and dissected.
Results: All samples had an identifiable saphenous vein and nerve. Each ankle also had at least one
deep branch off the saphenous nerve diving deep and medial becoming continuous with the
periosteum of the distal tibia. These branches divide from the saphenous nerve between 4-8 cm
above the medial malleolus. All ankles also had identifiable branches, which become continuous with
the capsule of the ankle joint around the medial malleolus. (Fig. 1)
[fig. 1]
Discussion: This cadaver study proposes that the saphenous nerve innervates the periosteum of the
distal tibia and medial ankle joint capsule. Deep branches of the saphenous nerve to the ankle are
difficult to identify upon routine dissection due to their fragility and small size, however they are
important clinically as they likely contribute to the sensory innervations of bony structures from the
medial ankle. As such, regional anesthetic techniques applied of the medial ankle should include the
addition of a saphenous nerve block to the sciatic nerve block.
References: 1 Williams PL, Bannister LH. Gray's Anatomy: The Anatomical Basis of Medicine and
Surgery. 38th ed. New York, NY: Churchill
Livingstone, 1995
Funding: Internally funded by the Department of Anatomy and the Department of Anesthesiology and
Perioperative Medicine
A49
STIMULATING CATHETERS DO NOT IMPROVE THE EFFECTIVENESS OF LUMBAR PLEXUS
BLOCK COMPARED WITH TRADITIONAL NONSTIMULATING CATHETERS. A PROSECTIVE,
RANDOMIZED DOUBLE BLINDED STUDY
1
2
1
2
2
1
L. Guzzetti , E. Basso Ricci , S. Turconi , F. Ruggieri , P. Ghisi , A.L. Ambrosoli , G. Cappelleri
1
2
2
Anesthesiology, Università degli Studi dell'Insubria, Varese, Università degli Studi di Milano, Milan,
4
Ospedale di Circolo Università dell'Insubria, Varese, Istituto Ortopedico Gaetano Pini, Milan, Italy
3
Introduction: Our prospective, randomized, double blinded study aims to detect if stimulating
catheters decrease the minimal effective volume (MEAV) of 1.5% mepivacaine for successful lumbar
plexus block (LPB) in 50% of patients compared with traditional non-stimulating catheters.
Materials and methods: After local ethics committee approval and written informed consent 50 ASA
I-III patients scheduled for primary, unilateral total hip arthroplasty were enrolled in the study and
randomized in two different groups. One group received continous lumbar plexus block by stimulating
catheter (group S: 25 patients) and one by nonstimulating catheters (group NS: 25 patients). To
calculate the MEAV 50 the up and down Dixon´s starcaise method was applied (p < 0.05 was
considered statistical significant).
Results: No differences in anthropometric data were found between the groups. The MEAV50
calculated in continuous lumbar plexus block was 27,40 ml (95% CI, 24,1-30,6) of 1,5% mepivacaine
in group S, and 26 ml (95% CI, 24,2-27,7) of 1,5% mepivacaine in group NS (p = 0.145).(Fig.1)
[Fig.1]
The time for catheter placing was statistically different: 180 (range 130-240) sec in the group S while
120 (range 95-180) sec in the group NS (p < 0.030); while no difference was found in obturator nerve
block.
Discussion: This prospective, randomized, blinded evaluation shows that stimulating catheters do
not reduce the minimum effective volume of local anesthetic (MEAV) required for lumbar plexus block.
Stimulating catheters have been advocated to minimize catheter misplacement and secondary block
failure, as they have been described to guide catheter tip closer to the target than non-stimulating
catheter (1). Our results do not support this hypothesis. Kirchmair and colleagues recently evidenced
that lumbar plexus is located within the psoas muscles in 98% of cases in cadavers (2). This location
could allows the spread of local anesthetic around the nerve even in case of progression of the
catheter far away from the target nerve. Moreover, in the present study non-stimulating catheter tips
were advanced only 2-3 cm over the needle tip, increasing the likelihood of proximity with the target
nerve.
In this study we observed bilateral spread of local anesthetic in one patient of group NS and two
patients of group S. Curiously, in one of this latter case the postoperative x-ray do not showed any
neuraxial spread of local anesthetic.(Fig.2)
[Fig.2]
In conclusion, stimulating catheters do not decrease the MEAV of 1.5% mepivacaine in patients
undergoing continuous lumbar plexus block compared with nonstimulating catheters. Furthermore our
study demonstrate that stimulating catheters do not prevent bilateral spread of local anesthetic and
further study needed to increase the knowledge of lumbar plexus block.
References:
1: Salinas FV et al. Prospective comparison of continuous femoral nerve block with nonstimulating
cathteter placement versus stimulating cahteter-guided perineural palcemente in volunteers. RAPM
2004;29:212-20.
2: Kirchmair L et al. Lumbar plexus and psoas major muscle: not always as expected. RAPM
2008;33:109-14.
Funding disclosure: Nothing to disclose.
Personal conflicts of interest disclosure: Nothing to disclose.
A50
THE CATHETER-OVER-NEEDLE ASSEMBLY FACILITATES DELIVERY OF A SECOND LOCAL
ANESTHETIC BOLUS TO PROLONG SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK
WITHOUT TIME-CONSUMING CATHETERIZATION STEPS
V.H.Y. Ip, B.C.H. Tsui, Edmonton Academy of Regional Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Supraclavicular brachial plexus block provides effective anesthesia for upper extremity
surgery. Current evidence for supraclavicular blocks is based largely on studies of single-shot
1,2
techniques since catheterized delivery of supraclavicular blocks can be challenging and time1
consuming to perform, and dislodgement and ineffectiveness are common problems. Here, we
demonstrate that a catheter-over-needle assembly can be used to deliver a supraclavicular block in
the same time taken to give a single-shot block, and that retention of the catheter throughout surgery
provides a means to deliver a second, post-operative bolus of local anesthetic, prolonging the
analgesic effect.
Material and methods: Patients were randomized into two groups: the control group received a
single-shot supraclavicular block with 25-30 mL of local anesthetic (1.5% lidocaine and 0.125%
bupivacaine mixture), while the study group received a supraclavicular block via a catheter-over3
needle assembly with the same volume and concentration of local anesthetic as in the single-shot
block, followed by a second, post-operative bolus of analgesic solution (20 mL of 0.2 % ropivacaine)
through the catheter prior to its removal (Figure 1-Arrows indicate the double-catheter assembly;
asterisk, inner catheter tip; oval, brachial plexus (BP)).
[CON assembly with the inner and outer catheter]
Duration of time between initial bolus and onset of pain as well as duration of pain relief from last
bolus were measured.
Results: Thirty patients were enrolled and randomized into the single-shot supraclavicular block
group (n=15) and the supraclavicular catheter group (n=15). One patient withdrew from the study, and
five patients were lost to follow-up. We observed no significant difference in block times between the
two groups (4.4 ± 2.7 min single shot vs. 3.1 ± 1.9 min catheter (p = 0.17)). Pain relief from initial
bolus to onset of pain lasted, on average, 617.5 (± 288.0) minutes for patients receiving the second
bolus compared to 377.2 (± 161.3) minutes for the single-shot control group (p=0.03).
Discussion: Importantly, delivering the supraclavicular block through the catheter took no more time
than the single-shot approach. Furthermore, the catheter was stable and remained in place
throughout surgery. These results suggest that placement of a catheter-over-needle assembly can be
an efficient method for delivering a supraclavicular block as well as providing a means to supplement
prolong the analgesic effect following discharge.
References:
1. Heil JW et al. J Ultrasound Med. 2010; 29: 1481-5
2. Mariano ER et al. Reg Anesth Pain Med. 2011; 36: 26-31
3. Ip V et al. Can. J. Anesth. 2012; 59: 1125-9
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society.
Personal conflicts of interest: The Pajunk MultiSet 211156-40E is modified and re-designed by Dr.
Ban Tsui. Dr. Tsui also has a patent-licensing agreement with Pajunk.
A51
MEPIVACAINE AND FENTANYL FOR SPINAL ANESTHESIA: A DOUBLE BLINDED
RANDOMIZED DOSE-RESPONSE TRIAL
R.L. Kahn, J.J. Bae, J.T. Ya Deau, J.G. Muller, J. Gonzalez, G.A. Liguori, J.D. MacGillivray, H.A.
Rose, R.J. Williams III, J. Curren, E. Chen, K. Fields
Hospital for Special Surgery, New York, NY, USA
Introduction: Thirty mg isobaric mepivacaine 1.5% plus 10 µg fentanyl produces reliable anesthesia
for knee arthroscopy, and has a more rapid recovery profile than 45 mg mepivacaine alone (1). This
study examined the dose-response of mepivacaine with and without fentanyl for spinal anesthesia.
Material and methods: Following written informed consent, subjects having out-patient knee
arthroscopy were prospectively randomized into one of 4 groups: mepivacaine 37.5 mg (group 37.5);
mepivacaine 30 mg plus fentanyl 10 µg (30/10); mepivacaine 27 mg plus fentanyl 10 µg (27/10); and
mepivacaine 24 mg plus fentanyl 10 µg (24/10). Success or failure of the spinal was judged by the
anesthesia provider and the surgeon blinded to group assignment. In the post-anesthesia care unit,
subjects were assessed every 15 minutes for sensory and motor block resolution by a blinded
research assistant. Prior to discharge, subjects rated their satisfaction with the OR experience, on a 1
to 10 scale (0 = very dissatisfied, 10 = very satisfied). Primary outcome was the duration from spinal
injection to ambulation.
Results: Fifty-six subjects were analyzed. Group 30/10 had 2 of 6 “fair” anesthetics and group 27/10
had 1 “fair” and 1 “inadequate” after 10 subjects, thus both were eliminated from further enrollment
per study protocol. Groups 37.5 and 24/10 had 1 “fair” anesthetic each, out of 22 and 18 subjects,
respectively. The recovery profiles showed little difference between groups 37.5 and 30/10 (except
faster resolution of motor block). Groups with lower doses of mepivacaine, 27/10 and 24/10,
demonstrated a shorter time to achieve recovery milestones than group 37.5.
Discussion: All groups had at least one incomplete anesthetic. The 3 fentanyl groups had a
combined incidence of 5/34 (15%, 95% CI 2.8 - 26.2%). Compared to the group 37.5, groups 27/10
and 24/10 had a recovery profile that was faster by approximately 30 minutes. This advantage of a
quicker recovery must be weighed against the probability of an incomplete anesthetic.
References: 1. Can J Anaesth. 2010 Jan;57(1):32-8
Funding: Department of Anesthesiology, Hospital for Special Surgery
The authors declare no conflicts of interest
M37.5 (N =
22)
M30/F10 (N
= 6)
M27/F10 (N
= 10)
M24/F10 (N
= 18)
Total (N =
56)
Anesthesia Rating, N
15/6/1/0
Perfect/Good/Fair/Inadequate
3/1/2/0
7/1/1/1
14/3/1/0
39/11/5/1
Surgeon's Rating, N
Perfect/Good/Inadequate
15/6/1
4/0/2
6/2/2
15/3/0
40/11/5
Patient Satisfaction with
Anesthesia, mean (SD) (0 =
worst, 10 = best)
9.9 (0.5)
10 (0)
9.9 (0.3)
10 (0)
9.9 (0.3)
Anesthesia Rating: Perfect=No response to surgery; Good=Minimal response controlled with
conscious sedation including up to 100 µg fentanyl; Fair=Requiring deep sedation;
Inadequate=Requiring general anesthesia; Surgeon's Rating: Perfect=No movement or patient
response; Good=Minimal movement; Inadequate=Unacceptable movement
[Table 1: Rating of spinal block]
G1 M37.5
(N = 22)
G2
M30/F10
(N = 6)
P (G1 vs
G2)
G3
M27/F10
(N = 10)
P (G1 vs
G3)
G4
M24/F10
(N = 18)
P (G1 vs
G4)
Time, min, mean (SD) From Induction End To:
Modified
Bromage
Scale of 0
161 (40)
127 (14)
0.033*
102 (35)
0.003**
99 (35)
0.0002**
Sensory
Block
Regression
to
Dermatome
Level S1
200 (38)
197 (27)
0.857
161 (32)
0.017*
162 (30)
0.006 **
First
Ambulation
225 (36)
215 (32)
0.538
178 (25)
0.004**
179 (31)
0.002 **
First
Urination
(>100 mL)
226 (35)
227 (38)
0.970
198 (35)
0.053
191 (41)
0.014*
Actual
Discharge
261 (43)
257 (40)
0.859
227 (31)
0.034*
220 (40)
0.011*
NRS pain score, mean (SD) (0 = none, 10 = worst)
Average
1.8 (1.5)
0.3 (0.5)
0.013*
0.7 (0.7)
0.033*
1.3 (1.7)
0.181
Worst
2.7 (2.1)
1.0 (1.5)
0.035*
1.4 (1.3)
0.078
2.6 (2.7)
0.603
[Table 2: Block characteristics by study group]
[Figure 1: Outcome distribution by study group]
A52
A DOUBLE-BLIND RANDOMIZED CONTROLLED TRIAL ON THE EFFECTS OF ULTRASOUND
PROBE POSITION ON ULTRASOUND GUIDED NERVE BLOCK
1
1
1
2
1
1
1
1
N.C.K. Lam , E.B. Baker , S. Fishburn , E. Mariano , E. Szabo , F. Jaime , A. Hammer , T. Petersen
1
Department of Anesthesiology and Critical Care Medicine, University of New Mexico, Albuquerque,
2
NM, Anesthesiology, Stanford, Stanford, CA, USA
Introduction: Proper needle visualization is imperative in achieving a successful anesthetic outcome.
1
At present, there are 2 basic probe positions that are being taught in the major teaching institutes in
the world. One technique involves a probe position perpendicular to the individual performing block
and the other involves a probe position parallel to the individual performing the block. This study was
designed to demonstrate if one technique is superior to the other in novices.
Methods: Healthy, right handed volunteers who were 18 years of age or older with no prior training
with ultrasound equipment were recruited. Thirty participants were randomized to two groups. Group
PEN received training using an instructional video that demonstrated probe position perpendicular to
the blocker (Figure 1). Group PAR received training using an identical instructional video that
demonstrated probe position parallel to the blocker (Figure 2).
[Figure 1]
[Figure 2]
2
Standardized phantoms were made of gelatin. Three straws were glued at a standardized diagonal
on the short axis such to simulate the neural structures in the interscalene region. The straws were
also glued at a standardized tilt on the long axis straws to produce the effect of anisotropy.
Each participant was asked to insert a 22G 80 mm Pajunk echogenic needle towards the 12'oclock
position of each straw in sequence using Esaote MyLab 1 ultrasound.They were asked to stop needle
advancement whenever the needle was not completely in view or when the targets (straws) were not
at their maximum brightness. This process was timed and viewed by the same assessing
anesthesiologist using a remote screen for the 30 participants. The participants repeated the task 3
times.
The participant, assessing anesthesiologist and statistician were blinded to the participants´
allocation.
Results: Participant performance was assessed by both time to completion (TTC) and the amount of
procedural time in which the needle was not visible (NNS) on the ultrasound screen. Time
measurements were truncated at 1000 seconds.
Results for Time to completion (TTC) of task for groups PAR and PEN
Video
Task 1 TTC (seconds) Task 2 TTC (seconds) Task 3 TTC (seconds)
Perpendicular (PEN)
87.5
78.6
65.5
Parallel (PAR)
638.3
543.6
466.8
Results for NNS as a proportion of time to completion for groups PAR and PEN
Video
Task 1 NNS (%)
Task 2 NNS (%)
Task 3 NNS (%)
Perpendicular (PEN)
52
50
47
Parallel (PAR)
87
84
79
[Results of TTC and NNS]
Discussion: It appears from our results that the group that was trained using the perpendicular probe
position, is clearly superior in terms of time to completion and the percentage of time that the needle
is seen.
References:
1. Hadzic A. et al.: Hadzic's Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional
Anesthesia. 2012;392.
2. Li JW. et al: Gelatin-agar lumbosacral spine phantom: a simple model for learning the basic skills
required to perform real-time sonographically guided central neuraxial blocks. J Ultrasound Med 2011.
Feb;30(2):263-72.
A53
THE ADDUCTOR CANAL BLOCK PROVIDES ANALGESIA SIMILAR TO A FEMORAL NERVE
BLOCK IN PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY - A RETROSPECTIVE
STUDY
M.E. Patterson, K. Bland, C. Elliot, S. Jayaswal, J. Soberon, L. Thomas, K. Osteen
Anesthesiology, Ochsner Medical Center, New Orleans, LA, USA
Background: Following total knee arthroplasty (TKA) a femoral nerve block (FNB) is commonly used
to provide analgesia (1), but its primary limitation is quadriceps weakness, which can limit physical
therapy. An adductor canal block (ACB) has been shown to be effective in providing analgesia
following knee surgery (2,3). Several nerves that innervate the knee traverse the adductor canal (4,5).
Unlike the FNB, the ACB is primarily a sensory block with little motor involvement. However, evidence
comparing the ACB to the FNB after TKA is lacking. The present study was performed to analyze the
ability of an ultrasound guided ACB to provide adequate analgesia as compared to the FNB in
patients undergoing TKA.
Methods: The study was a retrospective chart review of patients that had a primary unilateral TKA
between the dates of 7/1/12-10/31/12. Patients included in the study received either an ultrasound
guided single-shot ACB or a femoral nerve catheter (FNC). The local anesthetic for the ACB was 1530cc of 0.375 or 0.5% Bupivacaine and for the FNC 30-40cc 0.25% Ropivacaine was bolused
followed by a continuous infusion of 0.2% Ropivacaine. All patients received a Hydromorphone PCA.
Pains scores, opioid consumption and rescue femoral nerve blocks were recorded in PACU and at
8±3 and 24±3 hours.
Results: 60 patients received ACB and 51 patients received FNB; 47 (ACB) and 41(FNC) patients
were included in the analysis. Patients were excluded from analysis because of incomplete medical
records and 1 patient was unstable post-operatively unrelated to the nerve block. 91% (43/47) of
patients had a successful ACB and did not need a rescue FNC in PACU. At 8 and 24 hours, 83%
(39/47) and 70% (33/47) of patients did not require a rescue FNC, respectively. There was no
difference in VAS scores between the ACB and FNC groups in PACU, at 8 hours and at 24 hours
(Table 1). In addition, there was no difference in total hydromorphone used between the ACB and
FNC groups in PACU, at 8 hours, and at 24 hours (Table 2).
Discussion: This study demonstrates that an adductor canal block can provide analgesia as
effectively as a continuous femoral nerve block, at least within the first 24 hours following TKA.
VAS in PACU
VAS at 8 Hr
VAS at 24 Hr
Adductor Canal Group 1.7±1.9 (n=43)
2.8±2.2 (n=39)
2.9±1.7 (n=33)
Femoral Nerve Group 1.4±1.9 (n=41)
2.9±1.9 (n=41)
2.8±1.8 (n=41)
P-Value
0.8
0.7
0.5
[Table 1. Pain Scores (Visual Analogue Scale)]
Hydromorphone in
PACU
Hydromorphone at 8 Hr
Hydromorphone at 24
Hr
Adductor Canal Group
2.0±1.3 (n=43)
2.2±1.5 (n=39)
5.9±3.5 (n=33)
Femoral Nerve Group
1.6±1.3 (n=41)
2.8±1.8 (n=41)
7.4±4.6 (n=41)
P-Value
0.16
0.08
0.14
[Table 2. Cumulative Hydromorphone Usage (mg)]
References:
1. Anesth Analg 1998;87:93-97.
2. Knee Surg Sports Traumatol Arthrosc. 2008;16(9):855-8.
3. Acta Anaesthesiologica Scandinavica. 56(8):1013-9, 2012
4. Anat Rec. 1948;101(1):109-30.
5. Clin Orthop Relat Res. 1994;(301):221-6.
Funding: No manufacturer or third party funding
Conflicts: Nothing to disclose
A54
FUNCTIONAL OUTCOME FOLLOWING OUTPATIENT CONTINUOUS BRACHIAL PLEXUS
BLOCK FOR COMPLEX ARTHROSCOPIC ELBOW SURGERY
S. Riazi, C. Veillette, C. Tse, S. Abbas, V. Chan, A. Perlas
1
2
Anesthesia, Surgery-Division of Orthopaedic Surgery, University of Toronto, Toronto, ON, Canada
Introduction: The primary surgical aim of complex arthroscopic elbow surgery (CAES) is to improve
elbow range of motion. Immediate postoperative use of Continuous Passive Motion (CPM) equipment
1
plays a major role in acquiring optimal result and currently requires hospital admission for 72 hours.
Continuous brachial plexus (CBP) analgesia enhances patient compliance with CPM, and surgical
1
outcome by effectively relieving pain and is the preferred method of analgesia in several centers.
Outpatient management of CBP for less complex surgeries is associated with improved quality-of-life,
2
and cost-effectiveness. The goal of this study is to determine if early hospital discharge(23 hours
after CAES) with ambulatory CPM and CPB result in similar surgical and functional outcome
compared to standard inpatient-care.
Material and methods: This is a prospective, randomized, single-blinded, non-inferiority comparative
study. Following institutional research ethics approval, patients undergoing CAES were recruited, and
consented. Patients were randomized into 2-groups using computer-generated randomization
sequence. Surgical and anesthesia teams were blinded to group allocation until completion of
surgery. An ultrasound-guided infraclavicular brachial plexus catheter was placed postoperatively,
following neurovascular assessment by the surgeon. An initial bolus of 0.375% bupivacaine-30 mL
was followed by an infusion of ropivacaine-0.2% via a disposable elastomeric pump, continued for 60
hours on all patients. Patients were treated equally in all care aspects(pre-operative, intraoperative,
surgical approach, and CPM protocols), except for the discharge time.
Group IP: Home-discharge 72 hours postoperatively. Patients received standard inpatient care. CBP
was removed by an acute pain-physician 72-hours postoperatively (10 patients);
Group OP: Home-discharge with CBP 23 hours postoperatively. Patients were followed by an acute
pain-physician via daily telephone interviews and were given a 24-hour contact number. CBP was
removed by the patient 72-hours postoperatively (10 patients).
The primary outcome was the elbow range of motion “arc-ROM” (maximum flexion to extension) 2weeks after surgery. Pain scores and opioid consumption at postoperative days (POD)-1-3, as well as
DASH (Disabilities of the Arm, Shoulder, and Hand), and Short Form 12 (SF12) scores at 2, 6, and 12
weeks were assessed.
Results: This is an interim analysis of 20 patients for a projected n=40. Patient characteristics
(gender, age, and BMI) were similar between two groups. There was no significant difference in pain
scores, and morphine consumption on POD-1-3, as well as DASH score, and SF-12 at 2-weeks
postoperatively between two groups. Both groups achieved equally satisfactory and similar arc-ROM
at two weeks(118 +/-12 vs 124 +/-9).
Discussion: These preliminary results suggest that outpatient management of CAES with ambulatory
CPM and CBP is feasible and results in similar functional surgical outcome compared to current
standard inpatient management.
References:
1- O'Driscoll SW, Giori NJ.Continuous passive motion (CPM): theory and principles of clinical
application. J Rehabil Res Dev. 2000:37:179-88.
2- Ilfeld BM, Morey TE, Enneking FK. Continuous infraclavicular brachial plexus block for
postoperative pain control at home: A randomized, double-blinded, placebo-controlled study.
Anesthesiology 2002: 96:1297-1304.
Funding Disclosure: Drs. Riazi and Perlas receive academic time funding(Merit Awards) from the
Department of Anesthesia, University of Toronto. Authors acknowledge equipment support from
Philips, and Sonosite.
A55
ULTRASOUND GUIDED PERI-ARTICULAR INFILTRATION ANALGESIA FOR PATIENTS
UNDERGOING HIP ARTHROSOPY: A PROSPECTIVE, RANDOMIZED, DOUBLE-BLIND,
PLACEBO-CONTROLLED STUDY
S. Sinha, J. Abrams, S. Arumugam, J. Barnett, J. D'Alessio, D. Freitas, M. Joyce
1
2
Anesthesiology, Orthopedics, St. Francis Hospital and Medical Center, Hartford, CT, USA
Introduction: Managing postoperative pain after hip arthroscopy in an ambulatory setting is a
challenge. Even though peripheral nerve blocks provide adequate analgesia, they cause lower
extremity weakness and increase the risk of falls(1,2). This study evaluated the analgesic efficacy of
ultrasound-guided peri-articular infiltration oflocal anesthetic solution around the hip joint. Primary
outcome measure was peri-operative opioid consumption; secondary outcome measures were pain
scores, incidence of nausea/vomiting, time to discharge from post-anesthesia care unit (PACU) and
patient satisfaction.
Methods: Following IRB approval, 36 patients undergoing hip arthroscopy gave written, informed
consent. Patients were randomized to receive either an ultrasound-guided peri-articular infiltration with
30mL of ropivacaine 0.5% with epinephrine 1:200,000 (Group R) or normal saline 30mL (Group N).
After induction of general anesthesia (GA), with the patient in supine position, the hip joint was
imaged with a transducer placed inferior and parallel to the inguinal ligament. Using an ultrasoundguided in-plane approach the lateral, anterior and medial aspect of the hip joint was infiltrated with
30ml of injectate. Intra-articular injection was avoided.
GA was supplemented with fentanyl and hydromorphone as necessary by anesthesia care team. All
patients received odansetron 4mg, dexamethasone 4mg and ketorolac 30mg. The portal sites were
infiltrated with 20mL of bupivacaine 0.25% with epinephrine 1:200,000 by surgeon. After emergence
from GA, in PACU, numeric pain scores (0-10) were recorded and intravenous hydromorphone was
titrated for pain. Patients were discharged home from PACU when they met criteria and duration of
stay was recorded. All patients were prescribed naproxen 550 mg every 12 hours and
hydrocodone7.5mg+acetaminophen750mg tablets every 6 hours as needed for pain. At home, the
patients recorded pain scores every 6 hour for 24 hours, pain tablet consumption, any episodes of
nausea/vomiting and satisfaction with pain management.
Results: Demographic variables were similar between groups. Patients in Group R received
significantly lower amounts of hydromorphone intraoperatively and consumed fewer pain tablets at
home.(Table1). Lower pain scores was reported on admission and discharge from PACU in Group R
patients, however, pain scores at home were similar between groups.(Figure1) Patients in Group R
were discharged earlier from PACU compared to Group N patients. Incidence of nausea/vomiting and
patient satisfaction was similar between groups.
Group N N=18
Group R N= 18
95% CI Differences
p value
Intraop Fentanyl (µg)
median(min-max)
100 (75-200)
100 (100-200)
-26.8 to 24.1
.63
Intraop
Hydromorphone (mg)
median(min-max)
1 (0.4-1.8)
0.5 (0-0.8)
0.2 to 0.7
*.01
PACU
Hydromorphone (mg)
median(min-max)
0.8 (0-2)
0.6 (0-1.6)
-0.1 to 0.8
.12
PACU Time
(minutes) Mean(±SD)
133.7 (±38.6)
110.6 (±28.3)
0.1 to 46.1
*.01
PACU N/V (Yes/No)
5/13
5/13
Home Hydrocodone
+Acetaminophen (#
of Tablets consumed)
median(min-max)
4 (0-6)
3 (0-6)
Home N/V (Yes/No)
2/16
6/12
[Table 1. HIP ARTHROSCOPY STUDY SUMMARY STATISTICS]
1.0
-0.01 to 2.5
.05
.23
[Figure 1]
Discussion: Ultrasound-guided periarticular infiltration of ropivacaine reduces peri-operative opioid
requirements, decreases pain scores in PACU and facilitates earlier discharge.
References:
1. YaDeau et al. Anesth Analg 2012;115:968-972
2. Ward et al. Arthroscopy 2012;28:10641069
Funding: No External Funding
A56
SPINAL ANESTHESIA DOES NOT IMPACT PROSTATE CANCER RECURRENCE IN A COHORT
OF MEN UNDERGOING RADICAL PROSTATECTOMY
1
2
2
2
2
2
2
K.S. Tseng , S. Kulkarni , E.B. Humphreys , H.B. Carter , J.L. Mostwin , A.W. Partin , M. Han , C.L.
2
Wu
1
2
3
Anesthesiology, The Mount Sinai Hospital, New York, NY, Anesthesiology, Urology, Johns Hopkins
Hospital, Baltimore, MD, USA
Introduction: Prior studies have suggested a possible association between the use of neuraxial
anesthesia and a decrease in prostate cancer recurrence after radical prostatectomy.
Methods: After approval by the institutional review board, charts from consecutive radical
prostatectomy patients of three experienced urologists from January 1999 to December 2005 were
reviewed. In addition to the usual clinical and pathologic predictors of disease recurrence, patient
records were also queried for the type of anesthesia (general versus spinal) performed. The 5- and
10-year biochemical recurrence-free survival (BFS) was calculated using the Kaplan-Meier methods.
A Cox proportional hazards model was used to determine the statistical significance of predictors of
biochemical recurrence.
Results: A total of 1,970 patients - 1,172 and 798 receiving spinal and general anesthesia,
respectively - had complete pre-operative and follow-up data. Men who had spinal anesthesia had a
5- and 10-year biochemical recurrence-free survival of 88.2% and 83.5%. Men who had general
anesthesia had a 5- and 10-year BFS of 85.7% and 80.7% (figure 1). In univariate proportional
hazards analysis, the use of general anesthesia was associated with a trend towards an increased
risk of biochemical recurrence when compared with the use of spinal anesthesia (hazard ratio = 1.28,
95% confidence interval 0.99-1.65, p=0.055). However, when the type of anesthesia given was used
in a multi-variable analysis, the effect size (hazard ratio = 1.10, 95% confidence interval 0.85-1.42,
p=0.489) was diminished by clinical and pathologic variables.
Discussion: This was a retrospective study of patients with prostate cancer who have undergone
radical prostatectomy during a time period when the practice of anesthesia for prostatectomy at our
institution was transitioned from spinal to general endotracheal anesthesia. In our study, when
controlling for other predictors of advanced prostate cancer, the type of anesthetic given during
prostatectomy had no effect on the risk of biochemical recurrence.
Prior studies evaluating the oncologic benefit of regional anesthesia studied epidural anesthesia as an
adjunct to general anesthesia versus general anesthesia alone. They found mixed results: either a
1
significant reduction in risk of biochemical recurrence ; a significant reduction in risk of clinical
2
3,4
recurrence, but not biochemical recurrence ; or no significant difference . To our knowledge, this is
the first published study of spinal anesthesia as the primary anesthesia modality, as well as the
largest cohort studied to date. The absence of a positive association between prostate cancer
recurrence and spinal anesthesia in our study suggests that the relationship between neuraxial
anesthesia and prostate cancer may have more facets than previously estimated.
References:
1. Biki B, et al. Anesthesiology. 2008 Aug;109(2):180-7.
2. Wuethrich PY, et al. Anesthesiology. 2010 Sep;113(3):570-6.
3. Tsui BC, et al. Can J Anaesth. 2010 Feb;57(2):107-12.
4. Forget P, et al. Eur J Anaesthesiol. 2011 Dec;28(12):830-5
Funding: None
Personal conflicts of interest disclosure: Nothing to disclose
[Figure 1. Kaplan-Meier estimate ]
Univariate HR
(95% confidence
interval)
P-value
Multivariate HR
(95% confidence
interval)
P-value
Age
1.00 (0.98-1.02)
0.874
0.99 (0.97-1.01)
0.413
PSA 10 ng/ml or
greater (vs < 10
ng/ml)
3.47 (2.63-4.59)
< 0.001
1.72 (1.28-2.33)
< 0.001
Pathological
Gleason sum
3+4=7 (vs 5/6)
3.94 (2.75-5.63)
< 0.001
2.54 (1.74-3.70)
< 0.001
4+3=7 (vs 5/6)
11.8 (8.20-17.1)
< 0.001
5.90 (3.95-8.82)
< 0.001
8-10 (vs 5/6)
15.3 (10.5-22.4)
< 0.001
7.74 (5.11-11.7)
< 0.001
Pathologic stage
pT3a/b (vs pT2)
5.20 (3.90-6.95)
< 0.001
3.01 (2.21-4.11)
< 0.001
pT3c (vs pT2)
14.5 (9.72-21.7)
< 0.001
5.12 (3.30-7.95)
< 0.001
Lymph nodepositive (vs pT2)
17.0 (9.73-29.6)
< 0.001
4.74 (2.63-5.58)
< 0.001
General
anesthesia (vs
spinal)
1.28 (0.99-1.65)
0.055
1.10 (0.85-1.42)
0.489
[Table 1. Hazard ratio (HR) estimates]
A57
REPLACING CONTINUOUS FEMORAL NERVE BLOCKS WITH CONTINUOUS ADDUCTOR
CANAL BLOCKS WITHIN A CLINICAL PATHWAY FOR TOTAL KNEE ARTHROPLASTY: A
CASE-CONTROL STUDY OF POSTOPERATIVE AMBULATION
1,2
1
1,2
1
1,2
1
1
J.J. Workman , T.E. Kim , S. Howard , S. Mudumbai , N. Giori , S. Woolson , T. Ganaway , E.R.
1,2
Mariano
1
Anesthesiology and Perioperative Care, VA Palo Alto Health Care System, Palo Alto,
Anesthesiology, Stanford University, Stanford, CA, USA
2
Introduction: Continuous femoral nerve blocks have been shown to provide effective analgesia
following total knee arthroplasty (TKA) and may decrease time to achieve discharge eligibility;
however, there is a concern over quadriceps weakness which may contribute to patient falls. The
adductor canal offers a more distal perineural catheter insertion site which may help spare quadriceps
motor function without reduction in analgesia. The effects of continuous adductor canal blocks on
functional outcomes have not been well-established. This case-control study tests the hypothesis that
patients with continuous adductor canal blocks achieve greater maximum ambulation distance on
postoperative day (POD) 1 compared to patients with continuous femoral nerve blocks within an
established clinical pathway following TKA.
Methods: With IRB approval and waiver of informed consent, we retrospectively examined the
records of consecutive patients who underwent primary TKA over the course of one year, 6 months
prior and 6 months after replacing femoral nerve catheters with adductor canal catheters as part of a
clinical pathway. All other aspects of the clinical pathway (e.g., physical therapy regimen, nursing
care, standardize analgesic medications) remained the same during this time period. We further
refined our sample to include only cases performed by one surgeon with postoperative admission to
the primary surgical ward and excluded cases which involved additional significant surgical
procedures besides unilateral TKA. Our primary outcome was maximum ambulation distance (meters)
on POD 1. Secondary outcomes included ambulation distance at each physical therapy session, daily
opioid consumption, pain scores at rest and with movement during physical therapy, and hospital
length of stay. For normally-distributed data, single comparisons were performed using Student's t
test; for non-normal continuous data, the Mann-Whitney U test was used. The Z test or Barnard exact
test (n< 5 in any field) were used for comparisons of categorical data. A two-sided p< 0.05 was
considered statistically significant for the primary outcome.
Results: Of the 178 consecutive primary TKA cases performed in one year, 133 were removed
according to inclusion and exclusion criteria, leaving 45 cases (21 femoral; 24 adductor canal) for
analysis. Morphometric and procedural details were similar between groups (Table 1). For the primary
outcome of maximum ambulation distance, patients in the adductor group walked a median (10th90th percentiles) of 24 (0-60) meters vs. 6 (0-24) meters in the femoral catheter group (p=0.023). A
post-hoc power calculation revealed 89% power to detect this difference. Adductor canal patients
ambulated further than femoral catheter patients at 3 of 4 physical therapy time points (Figure 1). Pain
scores, daily opioid consumption, and hospital length of stay were similar between groups.
[Figure 1]
Conclusion: Continuous adductor canal blocks may allow patients to ambulate further than femoral
nerve blocks in the early postoperative period following TKA within an established clinical pathway
without reduction in analgesia. Confirmation of these findings through prospective study is warranted.
References:
1) Pain 2010;150:477-84;
2) Anesth Analg 2010;111:1552-4;
3) Anesthesiology 2013;2:409-15;
4) Acta Anaesthesiol Scand 2012;56:357-64.
A58
THE IMPACT OF SELECTION CRITERIA FOR BILATERAL KNEE ARTHROPLASTIES ON
PERIOPERATIVE OUTCOMES
1
1
1,2
1
1
S.G. Memtsoudis , L.A. Poultsides , O. Stundner , H. Do , M. Figgie , T.P. Sculco
1
1
2
Department of Anesthesiology, Department of Orthopedic Surgery, Hospital for Special Surgery,
3
Weill Medical College of Cornell University, New York, NY, USA, Department of Anesthesiology,
Perioperative Medicine and Intensive Care Medicine, Paracelsus Medical University, Salzburg,
4
Austria, Department of Epidemiology and Biostatistics, Hospital for Special Surgery, Weill Medical
College of Cornell University, New York, NY, USA
Introduction: Bilateral total knee arthroplasty (BTKA) procedures are associated with increased
morbidity and mortality, compared to unilateral approaches [1]. In an attempt to reduce this risk and
improve perioperative outcomes of patients undergoing this procedure, our institution has
implemented selection criteria in 2006 in order to select younger and healthier patients for BTKA (age
< 75 years, ASA I-II, absence of any major cardio-pulmonary morbidity) [2]. To date, however, the
effectiveness of such a strategy has not been evaluated. Therefore, we aimed at analyzing the impact
of the introduction of these guidelines on perioperative outcome.
Material and methods: All BTKAs performed consecutively at our institution between 1998 and 2011
were reviewed and included into the analysis. Patients were grouped according to date of surgery: (a)
before (1998-2005) and (b) after (2006-2011) introduction of the guidelines. Groups were compared in
terms of demographics, comorbidity burden and incidence of major perioperative complications.
Poisson regression was performed to obtain rate-ratios and proportional changes in complication rate,
adjusted for length of stay.
Results: The number of BTKA procedures performed at our institution was 1,968 before
implementation of the guidelines (1998-2005), and 1,992 afterwards (2006-2011). Patients in the
group before the introduction of selection criteria were older (65.8 years (SD 9.5) vs. 64.2 years (SD
8.5); p< 0.0001) and had a higher average comorbidity burden (Deyo-Index 0.38 (SD 0.9) vs 0.30 (SD
0.7); p=0.001). After introduction of the guidelines, the prevalence of cardiac and pulmonary comorbid
disease decreased, however, only the reduction in cardiac disease was statistically significant
(coronary artery disease: 8.2% vs 5.8%, p=0.0036; congestive heart failure: 1.5% vs 0.5%,
p=0.0006). The incidence of major complications decreased from 7.6% to 5.4% (p=0.0135). Major
constituents of this decrease were, specifically, reductions in the incidence of myocardial infarction
(0.6% vs 0.1%, p=0.0117) and other cardiac complications (2.8% vs 0.6%, p< 0.0001), whereas the
incidence of pneumonia and pulmonary embolism remained similar before and after the
implementation of guidelines. After 2006, the overall rate of major morbidity and mortality decreased
significantly, by 9% per year on average. The rate-ratio (RR) for combined complications comparing
post- vs. pre-intervention was RR=0.87 (CI 0.78;0.97; p=0.0141) indicating a significantly lower rate of
major complications after implementation of the guidelines. Although we saw decreases in rate-ratios
for individual cardio-pulmonary complications, only that for pulmonary embolism reached statistical
significance (RR=0.67 (CI 0.51;0.89; p=0.0049).
Discussion: After implementation of selection criteria for BTKA candidates at our institution, a
reduction in average age and comorbidity burden was accompanied by a reduction in incidence and
rates ratios of major morbidity and mortality. Although a causal relationship cannot be determined
using our dataset, and although other unmeasured variables may have contributed to this trend, our
results suggest that introduction of such guidelines can be associated with a reduction in
perioperative adverse outcomes.
A59
THE MAXIMUM EFFECTIVE NEEDLE-TO-NERVE DISTANCE FOR ULTRASOUND-GUIDED
INTERSCALENE BLOCK
E. Albrecht, K. Kirkham, R.V.W. Endersby, C. Tse, V.W.S. Chan, R. Brull
University of Toronto, Toronto, ON, Canada
Introduction: Direct needle trauma and intraneural injection are important mechanisms of nerve
injury associated with regional anesthesia. Despite ultrasound (US) guidance, unintentional
1
intraneural needle tip placement is common, especially during interscalene block (ISB). While
2
needle-to-nerve proximity is the fundamental requisite for a successful block, the maximum effective
distance between the needle tip and the target nerve is unknown. This study aimed to determine the
maximum distance the needle tip can be placed from the roots of the interscalene brachial plexus
while still achieving a successful block for shoulder surgery.
Material and methods: Twenty adult patients scheduled for ambulatory arthroscopic or open
shoulder surgery received an US-guided ISB using 20 mL of bupivacaine 0.5% with epinephrine. The
first block was performed with the needle tip positioned outside but in contact with the brachial plexus
sheath, at a location equidistant between C5-C6. For subsequent blocks, the Dixon up-and-down
method was followed: the distance from needle tip to sheath was increased or decreased by 2 mm for
each consecutive patient according to the block success or failure respectively, in the previous
patient. A successful block was defined as complete motor and sensory block in the C5 and C6
territories at 30 minutes. All patients received a general anesthetic. The primary outcome was the
maximum effective distance required to achieve a successful block in 50% (MED50) of patients.
Secondary outcomes included intraoperative and postoperative (Phase I recovery) fentanyl
consumption, pain scores upon arrival in Phase 1 recovery (numeric rating scale [NRS] out of 10),
duration of motor and sensory blockade, time to first dose of oral opioid analgesic at home, and
complications.
Results: The MED50 was 8.0 mm (95%CI: 6.0-10 mm). Figure 1 depicts the sequence of successful
and unsuccessful ISBs. Among the 11 patients with a successful ISB, the median intraoperative and
postoperative fentanyl consumption was 150 µg (Interquartile Range [IQR] 150-175 µg) and 75 µg
(IQR 25-75 µg), respectively. The median NRS pain score in Phase I recovery was 2 (IQR 0-3).
Median durations of motor and sensory blockade were 19.8 hours (h) (IQR 15.0-22.3 h) and 10.1 h
(IQR 8.5-12.2 h), respectively. The time to first dose of oral opioid analgesic at home was 9.6 h (IQR
9.3-12.1 h). No complications were reported.
[Up-and-down sequences of ISB for the MED50]
Discussion: A successful ISB can be achieved with a distance of 8 mm between the needle tip and
the brachial plexus sheath in 50% of patients. Our results suggest that it may not be necessary to
position the needle tip as close as possible to the nerve roots during US-guided ISB. Future studies
are required to explore the concept of maximum effective needle-to-nerve distance for other types of
peripheral nerve blocks with a view towards enhancing safety.
References:
1. Orebaugh SL et al. Subepineurial injection in ultrasound-guided interscalene needle tip placement.
Reg Anesth Pain Med.2010;35:450-454.
2. Moore DC. "No paresthesias-no
Anesth.1997;22:388-390.
anesthesia," the
Funding and interest disclosure: Nothing to disclose.
nerve stimulator
or
neither?
Reg
A60
THE IMPACT OF THE COMMON INVESTING EXTRA NEURAL LAYER ON MINIMUM
STIMULATION THRESHOLD CURRENT DURING ULTRASOUND-GUIDED SUBGLUTEAL
SCIATIC NERVE BLOCK
J. Buren, A. Brodskaia, M. Kendall, A. Nader
Feinberg School of Medicine Department of Anesthesiology, Northwestern University, Chicago, IL,
USA
Introduction: The two components of the sciatic nerve are enclosed by a dense connective tissue
that forms a common investing extraneural layer (CIEL) that extends along the trajectory of the sciatic
1
nerve. The minimum threshold current (MTC) that elicits a desired evoked motor response (EMR) is
frequently sought for sciatic nerve localization. MTCs ranging from 0.14 to 0.46 mA have been
2-5
reported in studies evaluating sciatic nerve analgesia. A previous study demonstrated thresholds
down to 0.3 mA at a pulse width of 100 µsec are required to achieve a success rate of 95% in patients
6
without polyneuropathy. We evaluated the relation between the needle tip and MTC required to elicit
an evoked motor response with the needle tip external and internal to the CIEL of the sciatic nerve.
Methods: After IRB approval, 139 patients undergoing knee replacement were recruited to
participate. A 21 g echogenic stimulating needle connected to the negative lead of the nerve
stimulator was directed toward the sciatic nerve using a subgluteal approach. The needle tip was
directed toward the medial component of the sciatic nerve under ultrasound visualization until
indentation of the CIEL was visualized and the MTC recorded. The needle was then advanced
between the components of the sciatic nerve, and the MTC was recorded. Patients were followed until
the resolution of the block and were contacted by phone at 2 weeks and at one month to evaluate
neurological symptoms. All patients were examined for neurological deficits at one month following
surgery using a calibrated filament. Minimum threshold currents were compared using a paired t-test.
Cumulative probabilities densities for above and below the CIEL minimal thresholds were calculated
(Figure 1).
Results: The mean MTC for above the CIEL stimulation was 0.52 ± 0.15 mA (95% CI 0.49-0.54)
compared to 0.19 ± 0.09 mA (95% CI 0.18-0.21) below the CIEL. The mean difference from above to
below was 0.32 ± 16 mA (95% CI 0.28-0.35). The lower 5% interval of the MTC outside the CIEL was
between 0.18-0.31 mA. The upper 5% interval of the MTC below the CIEL was between 0.33-0.44.
The highest mA recorded below the CIEL was 0.44mA while the lowest mA achieved outside the CIEL
was 0.18mA.
[Figure 1]
Discussion: Traversing the CIEL of the sciatic nerve substantially decreased the MTC needed to
obtain an EMR, suggesting that low MTC (< 0.31mA) is likely associated with 95% confidence that
needle positioning is below the common investing extraneural layer of the sciatic nerve in the
subgluteal region.
References:
1. Reg Anesth Pain Med 2012;37:363-5
2. Anesth Analg. 2004;99(2):584-8.
3. Anesthesiology. 2011;115(3):596-603.
4. Anesth Analg. 2009;108(1):359-63
5. Anesth Analg. 2010;110(3):951-7.
6. Anaesthesist. 2001 Mar;50(3):181-6.
A61
FORCE REQUIRED FOR DISPLACEMENT OF UNTUNNELED, TUNNELED AND DOUBLE
TUNNELED PERIPHERAL NERVE CATHETERS
K. Byrne, V. Freeman
Anaesthesia Department, Waikato Hospital, Hamilton, New Zealand
Introduction: There are no studies which objectively measure whether tunneling increases the force
required to displace a peripheral nerve catheter. This study aims to objectively measure the force
required to displace untunneled and tunneled catheters by 1cm, and introduces another technique,
double tunneling a catheter to further reduce the risk of catheter displacement.
Methods: Four freshly butchered pork shoulders were obtained from a local butchery. They were
o
stored at room temperature (20 C) until all had reached a uniform temperature, and the experiments
were conducted at room temperature. B.Braun contiplex catheter kits were used for all trials
containing 18G Tuohy needle and a 20G catheter.
1
A pre-experiment sample size calculation using variance from a previously conducted experiment ,
and an arbitrarily decided effect size of a 50% change in the force of displacement being clinically
significant, the number of trials needed to show a statistically significant difference between the
groups calculated at 13.
The 18G Tuohy needles were inserted to depth of 5cm at an angle of 45 degrees to the tissue
surface. The catheters were then fed to a distance of 8 cm at the skin and the needle then removed
without withdrawing the catheter. Subcutaneous tunnels were then formed for the tunneled and
double-tunneled groups by inserting the Tuohy needle subcutaneously inline with the exit point of the
catheter and the catheter fed retrogradely through the Tuohy needle.
A portable electronic scale (Wei-Heng WH-A05) with resolution of 5g was used to determine the force
used to dislodge the catheter by one cm was then attached to the end of the catheter by feeding the
catheter through a three way tap attached to a loop of tubing that was then attached to the hook on
the end of the scale.
Results: A 3 way anova comparison of the groups showed a highly significant (p < 0.0001) difference
between the 3 groups in the force required for displacement of the catheter by 1cm. The double
tunneled catheters required the most force to displace, the single tunnel the next most force to
displace, and the untunneled catheters required the least force to displace.
Discussion: This study shows a significant difference in the displacement force required for
peripheral nerve catheters in a porcine model when the catheter is either untunneled, tunneled or
double tunneled. This seems to indicate that the simple act of tunneling the catheter should be
recommended for all continuous nerve blockade techniques.
Double tunneling is a new technique which does not seem to be have been described in the literature
previously. In this study catheters that were double tunneled were associated with nearly a four fold
increase in force required for displacement compared to single tunneled catheters, and a 17 fold
increase in force of displacement compared to untunneled catheters.
References: 1. Tsui BC, Tsui J. Less leakage and dislodgement with a catheter-over-needle versus a
catheter-through-needle approach for peripheral nerve block: an ex vivo study. Can J Anaesth
2012;59:655-661.
Funding: B.Braun provided all the catheter kits free of charge
A62
VARIABILITY IN ANESTHETIC CARE FOR TOTAL KNEE ARTHROPLASTY IN THE UNITED
STATES
1
1
1
1
1
2
P. Fleischut , L. Gaber-Baylis , R. Rasul , S. Faggiani , M. Mazumdar , R. Dutton , S. Memtsoudis
1
1
2
Anesthesiology, New York-Presbyterian Hospital, Weill Medical College of Cornell University, Public
3
Health, Weill Medical College of Cornell University, New York, NY, Anesthesia Quality Institute, Park
4
Ridge, IL, Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University,
New York, NY, USA
Background: With a volume of over 700,000 procedures performed annually, total knee
arthroplasties are one of the most commonly performed orthopedic inpatient surgeries in the US.
However, little is known about the utilization and related characteristics of various anesthetic practices
in the United States. Therefore, we sought to characterize anesthesia practice patterns utilizing the
largest national anesthesia database provided by the Anesthesia Quality Institute (AQI).
Methods: We utilized data collected by the AQI between 2010 and 2012 and identified all primary
total knee arthroplasties. The proportion of cases performed primarily under general, neuraxial or
regional anesthesia was determined. The average anesthesia times for each type were determined.
The utilization of the various types of anesthesia was further analyzed by anesthesia provider model
(solo anesthesiologist, anesthesiologist working with resident or anesthesiologist working with CRNA),
by anesthesiologist's board certification status, by patient characteristics (age, gender, ASA physical
status) and by facility type (University hospital, large/medium/small community hospital). Chi-squared
test was used to determine differences between groups for categorical variables. For continuous
variables, means and ANOVA tests were analyzed to compare groups. A P-value of < 0.05 was
considered to indicate a significant difference between groups.
Results: We identified a total of 95,176 cases of total knee arthroplasty of which 81% had available
information on the primary anesthesia type used. Of those 53%, 36% and 10% were performed under
general, neuraxial or regional anesthesia respectively. Average anesthesia times were 149, 141 and
137 minutes, respectively (P < 0.0001). Patients undergoing general anesthesia were on average
younger (64.3, 67.0, and 67.6 years (P < 0.0001). Gender distribution among groups was similar
(female 59%, 63%, and 60%, P < 0.0001). The proportion of patients with an ASA class of 3 and
higher was highest in the regional anesthesia group (38%, 38%, 46% (P < 0.0001). A resident was
more commonly part of the anesthesia care team when neuraxial anesthesia (9%) compared to
general (5%) was used. The opposite was true for CRNA involvement (45% vs. 41%, (P < 0.0001).
When regional was the primary type of anesthesia, residents were involved in 3% and CRNAs 52% of
the time. When a neuraxial or regional technique was used as the primary type of anesthesia, the
anesthesiologist was more frequently board certified than when a general anesthetic was provided
(79%, 72% and 54%, respectively (P< 0.0001). The majority of cases (>94%) were performed in
community hospitals. Proportionally, most procedures under general and neuraxial anesthesia were
performed in medium-sized community hospitals (60% and 71%), while the biggest proportion of
primarily regional anesthesia cases took place in large community hospitals (47%). The utilization of
general, neuraxial and regional as a proportion of individual practices varied significantly (14%-100%,
0%-86%, and 0%-84% (P < 0.0001).
Conclusion: After preliminary analysis, considerable variation of the utilization of anesthetic
techniques was found for the performance of total knee arthroplasty among AQI participating
practices. Variability was further seen related to patient and anesthesia provider characteristics.
Reasons for these finding remain unclear and analysis is ongoing.
A63
EFFECTS OF STEROIDS ON THROMBOGENIC MARKERS IN PATIENTS UNDERGOING
UNILATERAL TOTAL KNEE SURGERY
K. Jules-Elysee, T. Sculco, J. Beathe, J.T. YaDeau, V.L. Buschiazzo, A. McLawhorn, E. Purdue, Y.
Ma
1
Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University,
3
Orthopedics, Hospital for Special Surgery, Orthopedics, Weill Medical College of Cornell University,
4
5
Research Division, Epidemiology and Biostatistics, Hospital for Special Surgery, New York, NY,
USA
2
Introduction: In spite of thromboprophylaxis therapy, deep vein thrombosis (DVT) and pulmonary
embolism (PE) still remain important complications in patients undergoing total knee arthroplasty
(TKA).Systemic thrombin generation starts in the early peri-operative period as demonstrated by a
rise in thrombogenic markers 4 hours post-surgery. Inflammation characterized by a rise in IL6 with
surgery is thought to play a major role in the initiation of coagulation pathway via expression of tissue
factor. In addition low dose steroids have been shown to stimulate tissue plasminogen activation
leading to fibrinolysis.
In this study, we assessed the effect of steroids on the release of thrombogenic markers, plasmin antiplasmin (PAP), a marker of fibrinolysis and prothrombin fragment (PF 1.2) a marker of trombin
generation.
Methods: This triple blinded placebo controlled study was approved by hospital IRB. The study group
received 100 mg of intravenous hydrocortisone 2 hours prior to surgery, followed by an additional 2
doses, each 8 hours post-op. The control group received normal saline at each time point. Blood
samples were taken pre-incision and at 4 hours post tourniquet (TQ) release. Blood was centrifuged
at 3500 rpm, and the supernatant examined.
The samples were subsequently assayed for PAP and PF 1.2.
Results: A total of 24 patients undergoing unilateral TKA were included in the study (13 in the
placebo group, 11 in the study group). The change in PF 1.2 between baseline and 4 hours post TQ
in the control group was significantly greater compared to the study group (674+/- 260 vs. 349+/- 332;
p-value 0.01) In addition, the study group had significantly lower PF 1.2 at 4 hours compared to the
control group (615 +/- 357 vs. 937+/- 317; p-value 0.04). Although PAP was higher in the study group
at 4 hours, 1638 +/- 823 vs. 1206 +/- 624, it did not reach statistical significance (P=0.18).
Conclusion: This dose regimen of steroids significantly decreased the amount of thrombin generation
seen with TKA without interfering with fibrinolysis. The mechanism is most likely due to decreased
inflammation from reduced IL6 levels. This may have major clinical implications in terms of post-op
DVT or PE. Clinical studies are needed for further evaluation.
References:
1. Reikeras et al. Thrombosis markers in hip versus knee arthroplasty: a pilot study Journal of
Orthopaedic Surgery 2009; 17(3):291-5.
2. Jules et al. Use of low-dose steroids in decreasing cytokine release during bilateral total knee
replacement. RAPM. 2011 Jan-Feb; 36 (1):36-40.
N
Age Avg.
TQ time Avg.
Blood loss
Avg.
PF 1.2 4hrs
post-op
(pMol/L)
PAP 4hrs
post-op
(mcg/L)
Placebo
13
66.6
46
213
937 ± 317
1206 ± 624
Treatment
11
68
44
206.2
615 ± 357
1638 ± 823
0.04
0.18
P-Value
[Unilateral Patients]
A64
ULTRASOUND-GUIDED TRANSVERSUS ABDOMINUS PLANE (TAP) BLOCK FOR
LAPAROSCOPIC GASTRIC-BYPASS SURGERY: A PROSPECTIVE RANDOMIZED
CONTROLLED DOUBLE-BLINDED TRIAL
K.R. Kirkham, E. Albrecht, R.V.W. Endersby, V.W.S. Chan, T. Jackson, A. Okrainec, T. Penner, R.
Jin, S. Abbas, R. Brull
1
2
Anesthesia and Pain Management, UHN - Toronto Western Hospital, Anesthesia, University of
3
Toronto, Surgery, UHN - Toronto Western Hospital, Toronto, ON, Canada
Introduction: Despite the laparoscopic approach, patients can suffer moderate to severe pain
1
following bariatric surgery. The transversus abdominis plane (TAP) block has been demonstrated to
2
3
improve pain-related outcomes after both laparoscopic and open abdominal procedures. This
randomized controlled double-blinded trial investigated the analgesic efficacy of ultrasound-guided
TAP blocks for laparoscopic gastric-bypass surgery (LGBS).
Materials and methods: Seventy patients undergoing LGBS were randomized to receive either
bilateral ultrasound-guided subcostal TAP block injections after induction of general anesthesia or
none. All patients received trochar insertion site local anesthetic infiltration and systemic analgesia.
The primary outcome was cumulative opioid consumption (IV morphine equivalent) during the first 24
hours postoperatively. Interval opioid consumption, pain severity scores, and rates of nausea or
vomiting were measured during Phase I recovery, and at 24 and 48 hours postoperatively.
Results: There was no difference in cumulative opioid consumption during the first 24 hours
postoperatively between the TAP (31.6 mg [95%CI: 26.9 - 36.4]) and control (34.2 mg [95%CI: 27.7 40.5]; P=0.52) groups. However, opioid consumption during Phase I recovery was significantly less in
the TAP (13.5 mg [95%CI: 11.2 - 15.9]) compared to the control (17.2 mg [95%CI: 14.4 - 20.0];
P=0.04) group. Postoperative opioid consumption during the 24-48 hour interval was similar between
groups, as were pain scores at rest and with movement during all measured intervals. The rate of
nausea or vomiting was less during Phase I recovery in the TAP (13.8%) compared to the control
(38.2%; P=0.04) group with no measurable differences during any interval thereafter. There were no
complications related to any of the block procedures.
Discussion: Bilateral TAP blocks performed prior to surgical incision do not provide additional
analgesic benefit beyond Phase I recovery when added to trochar insertion site local anesthetic
infiltration and systemic analgesia for laparoscopic gastric-bypass surgery.
References:
1. Tufanogullari B, White PF, Peixoto MP, et al. Dexmedetomidine infusion during laparoscopic
bariatric surgery: the effect on recovery outcome variables. Anesth Analg. 2008;106:1741-1748.
2. El-Dawlatly AA, Turkistani A, Kettner SC, et al. Ultrasound-guided transversus abdominis plane
block: description of a new technique and comparison with conventional systemic analgesia during
laparoscopic cholecystectomy. Br J Anaesth. 2009;102:763-767.
3. Ra YS, Kim CH, Lee GY, Han JI. The analgesic effect of the ultrasound-guided transverse
abdominis plane block after laparoscopic cholecystectomy. Korean J Anesthesiol. 2010;58:362-368.
Funding: Dr. Richard Brull is supported by the Merit Award Program, Department of Anesthesia,
University of Toronto.
Personal Conflicts of Interest Disclosure: Nothing to disclose.
A65
IS THERE A DOSAGE EFFECT OF DEXAMETHASONE AS AN ADJUVANT FOR BRACHIAL
PLEXUS NERVE BLOCK? - A PROSPECTIVE RANDOMIZED DOUBLE-BLINDED CLINICAL
STUDY
J. Liu, K.A. Richman, N. Elkassabany
Anesthesiology and Critical Care, The University of Pennsylvania, Philadelphia, PA, USA
Introduction: Brachial plexus block is a great option for postoperative pain management after
shoulder arthroscopy. Dexamethasone, as an adjuvant, to local anesthetics further expanded our
capability to provide longer duration of analgesia with a single shot nerve block. Recent evidence
showed that that 8mg of preservative-free dexamethasone has been able to prolong the analgesia
duration of brachial plexus nerve block by 50 to 100 percent. There is only one study with reduced
dosage of dexamethasone of 4mg by Dr. Nader´s group. The authors observed decreased analgesia
duration from 25.2 to 21.6 hours, while not statistic significant.
The safety of adding dexamethasone and the implication to the incidence of neuronal damage are still
in question. Available studies failed to draw any definitive conclusion about the safety of adding
dexamethasone because of the limited number of the studies and the small sample size in each. It is
appealing that lower dose of dexamethasone may be clinically effective with decreased risks. We
hypothesize that dexamethasone as an adjuvant to local anesthetic has dose response effects in
regards to the duration of sensory and motor nerve blocks.
Methods: The study was reviewed and approved by the institutional review board of the University of
Pennsylvania. We proposed to recruit 100 outpatient patients undergoing shoulder arthroscopic
surgery between the age of 18 to 70 with ASA I-III physical status. All patients will receive general
anesthesia and an ultrasound guided supraclavicular brachial plexus nerve block with 30ml of 0.25%
bupivacaine. All patients will be randomly assigned into one of four groups: control group, 1mg
dexamethasone, 2mg dexamethasone, or 4mg dexamethasone in addition to 0.25% bupivacaine. All
patients will be interviewed over the phone on post-operative day 1, day 2, and day 7. The recovery of
sensory, motor, time to first opioid requirement, and opioid consumptions will be recorded. All data will
be analyzed via ANOVA.
Results: Currently, we have recruited over 40 patients into the study. Preliminary data analysis
showed that duration of analgesia was significantly prolonged in all groups received dexamethasone.
The average analgesia duration of plain 0.25% bupivacaine was 15.7 hours, while average analgesia
durations were 22.4, 23.4, and 22.2 hours for dexamethasone 1mg, 2mg, or 4mg group respectively.
The average durations of motor block showed similar trend.
Discussion: Our preliminary data analysis showed no dose response effect of dexamethasone as an
adjuvant to local anesthetic for brachial plexus nerve block. The addition of dexamethasone to
bupivacaine significantly prolonged the duration of sensory and motor nerve block. In addition, our
preliminary finding indicated shorter motor block duration than sensory block. We are currently
actively recruiting additional patients into this study.
A66
COMPARATIVE STUDY OF GENERAL ANESTHESIA VERSUS LOCAL ANESTHESIA FOR
CAROTID ENDARTERECTOMY
H. Martinez-Wilson, J. Liu
Anesthesiology and Critical Care, The University of Pennsylvania, Philadelphia, PA, USA
Background: Carotid endarterectomy (CEA) is an effective tool in reducing stroke risk in selective
patient groups. The ideal anesthetic technique remains controversial in light of available literature,
which has shown no difference in postoperative mortality between general anesthesia (GA) and local
anesthesia (LA) for CEA. The American College of Surgeons National Surgical Quality Improvement
Program (NSQIP) is a nationally validated, risk-adjusted, outcome-based program used to measure
surgical outcomes. A retrospective study of the NSQIP database between 2005 and 2009 looking at
the composite risks of stroke, myocardial infarction, and death did not show significant patient
1
outcome differences between GA and LA groups (2.8% versus 3.6%) undergoing CEA . However, no
detailed information on each individual risk was reported. With this in mind we set to investigate the
individual complications on the nervous and cardiovascular systems during LA or GA for CEA. We
hypothesized that LA is associated with lower 30-day post-operative cardiac risk, including cardiac
arrest and myocardial infarction.
Methods: We studied the American College of Surgeons National Surgical Quality Improvement
Program database from 2005 to 2010. There were total of 34353 patients included in our final cohort,
with 28969 patients receiving general anesthesia and 5384 patients receiving local, regional
anesthesia, or monitored anesthesia care (LRA). The outcome measurements of 30 days postoperative complications included stroke, coma, cardiac arrest, myocardial infarction, and death.
Results: The overall mortality was 0.76% and 0.76% between LRA and GA subjects respectively
(P=0.932). There were no differences in regards to stroke (1.45% versus 1.57%), coma (0.09%
versus 0.08%), and cardiac arrest occurrence (0.22% versus 0.30%). However, LRA group had
significant lower risk of myocardial infarction risk (0.32% vs. 0.74%, P< 0.001).
Conclusions: This study suggests that, in comparison to GA, patients receiving local, MAC, and/or
regional anesthesia had a significant lower risk of postoperative MI. Though this study is limited by the
data available through the NSQIP database, it should serve as a framework to build a more
comprehensive study looking at post operative MI in patients receiving GA versus local, MAC, and/or
regional anesthesia.
Reference:
1. Schechter MA, Shortell CK, Scarborough JE. Regional versus general anesthesia for carotid
endarterectomy: the American College of Surgeons National Surgical Quality Improvement
Program perspective. Surgery. 2012 Sep;152(3):309-14
A67
A RANDOMISED COMPARISON OF COMBINED SUPRASCAPULAR AND AXILLARY
(CIRCUMFLEX) NERVE BLOCK WITH INTERSCALENE BLOCK FOR POSTOPERATIVE
ANALGESIA FOLLOWING ARTHROSCOPIC SHOULDER SURGERY
D. Price, A. Abeysekera, M. Chaddock
North Shore Hospital, Auckland, New Zealand
Introduction: Interscalene block (ISB) is the gold standard technique for analgesia following shoulder
surgery. However it is associated with a high frequency of well-known side effects, and has the
potential to result in serious complications. The aim of this randomised controlled study was to
determine whether an alternative technique, combined suprascapular and axillary (circumflex) nerve
block (CSANB), could provide analgesia comparable to ISB, with a reduction in the rate of side effects
and complications.
Methods: 106 consecutive patients undergoing minor arthroscopic shoulder surgery were
randomised. In Group ISB, 30ml of 0.75% ropivacaine was injected on location of the C5,6 roots. In
Group CSANB, 15ml of 0.75% ropivacaine was injected in the vicinity of each nerve using the
1
combined Meier-Price technique . All patients underwent general anaesthesia as per protocol.
CSANB also received 3 to 6mg of morphine intraoperatively, on a per weight basis.
Results: Area under the curve of numerical rating pain scores (NRPS) recorded on emergence and at
1, 2, 6 and 24 hours postoperatively, showed no statistical difference between groups at rest.
Movement NRPS were statistically higher in CSANB. The NRPS vs time curve profile differed
between groups, with higher pain scores up to 6hrs for CSANB, and at 24hrs for ISB. Opiate
consumption mirrored pain scores: CSANB consumed higher levels of intravenous morphine in first 2
hrs, but reported lower oral oxycodone requirements between 6 and 24hrs (Table 1). ISB were more
likely to report the time at which the block receded and pain intensified (Table 1). CSANB patients
were less likely to describe a dislike of side effects, and their reduction in peak expiratory flow rate
postoperatively was less significant
Conclusion: ISB provides superior analgesia in the first 2 hrs postoperatively, but at the cost of more
significant side effects. From 6hr to 24hr, pain relief appears superior with CSANB.
References:
1. Price DJ. The shoulder block: a new alternative to interscalene brachial plexus blockade for the
control of postoperative shoulder pain. Anaesthesia Intensive Care 2007;35:575-581
Funding disclosure: This project was funded by an Australia and New Zealand College of
Anaesthetist Novice Research Grant, awarded in 2009.
There are no conflict of interest disclosures to make.
[Table 1]
[Table 2]
A68
ANATOMICAL RELATIONSHIP OF THE POPLITEAL ARTERY AND SCIATIC AND TIBIAL
NERVES: RELEVANCE TO POPLITEAL SCIATIC NERVE BLOCK
G. Woodworth, J. Trujillo, E. Foss, M. Semenza II
1
2
Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
Introduction: Ultrasound-guided sciatic nerve block in the popliteal fossa is a common regional
anesthetic approach for distal lower extremity surgery. (1, 2) Due to occasional difficulties in locating
the sciatic nerve, one technique is to identify the popliteal artery in the popliteal fossa and use it as a
landmark to identify the tibial nerve. The nerve can then be traced back to its bifurcation from the
sciatic nerve. (3, 4)
Prior studies have demonstrated the anatomical variability of the bifurcation of the sciatic nerve in the
posterior knee and thigh, and the variability of the popliteal artery in the popliteal fossa; however, to
our knowledge, no published studies have directly examined the variability of the sciatic nerve to the
popliteal artery. In this study we examined the anatomical relationship of the popliteal artery and the
tibial or sciatic nerve at three different locations in the popliteal fossa.
Methods: Axial MRI scans of the knee for 100 subjects were examined. The angle and distance from
the popliteal artery to the target nerve was recorded at measurement points 0, 5, and 8 cm proximal to
the distal femur. The mean distance and angle between the popliteal artery and tibial nerve was
calculated. The distances and angles were correlated with BMI.
Results: At the distal femur the tibial nerve is within a few millimeters of the popliteal artery. (Table 1)
Although in all cases the nerve was posterior to the artery, the nerve was variably distributed medial
and lateral to the artery. (Figure 1) At 5 cm proximal to the distal femur, the nerve was always
posterior to the artery and in greater than 95% of cases posterolateral to the artery at a mean
distance of 9.9 mm. At 8 cm proximal to the femur, the nerve was always posterior to the artery and in
greater than 95% of cases posterolateral to the artery at a mean distance of 16.1 mm. BMI was
significantly correlated with the distance between the artery and the nerve with the effect strongest at
8 cm proximal to the distal femur. Figure 1 is a scatter plot detailing the location of the tibial/sciatic
nerve in relation to the popliteal artery. Plot A, B and C represent 0, 5 and 8 cm proximal to distal
femur. The 0/0 location identifies the popliteal artery.
Distance proximal
from distal femur
0 cm
5 cm
8 cm
Mean distance from
nerve to poplital artery
in mm (SD)
2.8 (1.9)
9.9 (4)
16.1 (5.2)
Mean angle from nerve
to popliteal artery in
degrees (SD)
21 (21)
-31 (15)
-44 (16)
[Distance and Angle of Nerve to Popliteal Artery]
[Figure 1]
Discussion: The data from this study provide valuable information when using the popliteal artery as
an anatomic landmark to identify the tibial/sciatic nerve. At 5 cm proximal to the distal femur the
popliteal artery can reliably be used as an anatomic landmark to locate the tibial/sciatic nerve due to
the close proximity and consistent location of the nerve posterolateral to the artery.
References:
1) Anesthesiology 2006;104:309-314.
2) RAPM 2008;33:369-376.
3) RAPM 2006;31:481-482.
4) RAPM 2008;33:281-282.
A69
APPROACHES TO TOTAL KNEE ARTHROPLASTY AT UNC: MULTIMODAL REGIONAL
ANESTHETICS VERSUS MONOMODAL GENERAL ANESTHETICS
B. Sumrow, A. Powell, M.Y. Qadri, A. Bortsov, R. Coombs
1
2
University of North Carolina, Department of Anesthesiology, UNC Hospitals, Chapel Hill, NC, USA
Background: Traditionally total joint arthroplasty was performed under general endotracheal
anesthesia (GETA). This approach has been abandoned by many surgeons in favor of
neuraxial/regional approaches. Proponents of this shift cite improved pain control, decreased
perioperative complications, and shorter hospital stays. At UNC Hospitals there remains a dichotomy
between the approaches to total knee arthroplasty (TKA) based on surgeon preference. This study
aims to compare patient outcomes between those who receive a structured, regional-based,
multimodal-analgesic approach versus the outcomes of patients who receive a general anesthetic.
Methods: Medical records of each patient at UNC Hospitals receiving a TKA between 9/2011 and
5/2012 were identified. Using PACU nursing notes, CPA documentation, and discharge summaries,
the following retrospective data was recorded: performing surgeon, use of GETA, age/gender,
intraoperative opioid totals (morphine equivalents), PACU opioids received, PACU pain scores, PACU
length-of-stay, days to hospital discharge, presence of postoperative peripheral nerve block (PONB),
and presence of postoperative epidural (POE). Distributions of the outcome measures were explored
using standard statistics (mean, median, standard error, range), comparing the two approaches as
well as patients receiving general anesthetics versus those that did not. Differences between groups
were assessed with the Student t-test. Multivariate regression was used to identify independent
predictors of the outcomes. P-values < 0.05 were considered statistically significant.
Results: A total of 94 cases were examined. Nineteen cases were performed under GETA and 71
were performed primarily with a regional/neuraxial technique. Of the 94 cases, 10 required PONB and
10 required POE, with two patients requiring both PONB and POEs. Ketamine was used in 29/94
cases. Comparing GETA vs Non-GETA, significant differences were found between intraop and total
opioid use, PACU pain scores, and days to discharge. Patients undergoing GETA received more
intraoperative opioid (34.1 ± 3.2 vs 13.2 ± 1.7 MEs, mean ± SE, p < 0.0001) and total opioid during
their stay (49.8 ± 6.3 vs 20.5 ± 3.3, p < 0.0001). GETA patients also had higher pain scores on arrival
to the PACU (4.4 ± 0.8 vs 2.0 ± 0.4 on a scale from 0 - 10, p = 0.011) and higher maximum pain
scores during their PACU stay (6.3 ± 0.9 vs 3.8 ± 0.5, p = 0.013). In our cohort, no significant
differences were found in the length of stay in the PACU between individuals undergoing GETA or
regional techniques (135.8 ± 21.9 vs 142.5 ± 11.2 minutes, p = 0.781). However, there was a
significant difference between days-to-discharge between the two groups, with those undergoing
GETA staying significantly longer than those undergoing regional anesthesia (5.05 ± 0.4 vs 3.2 ± 0.2
days, p < 0.0001).
Conclusions: This study demonstrates that a regional anesthetic approach decreases intraoperative
and postoperative opioid requirements, postoperative pain scores in the PACU, and days to
discharge. PACU length of stays were not dependent upon anesthetic technique, despite these other
significant decreases seen with the use of regional anesthesia techniques. Future work may involve
larger cohorts, more surgeons, and a more structured regional technique.
A70
THE SUCCESS AND DURATION OF SCIATIC NERVE BLOCK USING 0.5% BUPIVACAINE OR
ROPIVACAINE AT DIFFERENT VOLUMES: A DOUBLE BLIND RANDOMIZED CLINICAL TRIAL
D. Szczodry, M.C. Kendall, R.J. McCarthy, A. Nader
Anesthesiolgy, Northwestern University, Chicago, IL, USA
Introduction: Sciatic nerve contains a tibial and peroneal component surrounded by common
1
investing extraneural layer (CIEL). Traditional nerve stimulator guided technique requires large
2
volume of local anesthetic (LA) to perform successful sciatic nerve block (SNB). This prospective
double blind randomized study was designed to determine the effect of wide range of volumes of LA
injected beneath the CIEL on the onset, success and duration of SNB.
Material and methods: After IRB approval, 139 adult patients scheduled for total knee arthroplasty
consented to participate. All subjects received an ultrasound-guided nerve stimulator assisted SNB
using the infragluteal-parabiceps approach. Subjects were randomized into 14 groups to receive 0.5%
bupivacaine or 0.5% ropivacaine with epinephrine 1:300,000 in volumes ranging from 2.5ml to 30ml
(12.5mg- 150mg). An evoked motor response of plantar flexion or inversion was sought. Following LA
injection, sensory and motor assessments (3-point scale) were performed by a blinded investigator
every 2 min for 10 min and at 5min intervals until 60 min prior to surgery. Motor and sensory block
were assed every 4hrs until complete SNB resolution. Successful block was defined as a complete
pinprick sensory and motor block at 60min in the distribution of the sural, tibial, deep and superficial
peroneal nerves. The duration of sensory and motor block were recorded.
Results: 139 subjects completed the study. There was no difference in patient characteristic between
groups. Injection volume of 2.5 and 5ml were associated with delayed onset and a dose dependent
decrease in block duration and a greater fraction of subjects experiencing pain behind the knee in the
ropivacaine group. Injection volumes ≥10ml produced complete block within 30min.
[Figure 1]
Conclusions: Injecting 10 ml of 0.5% bupivacaine or 0.5% ropivacaine below CIEL produces duration
of sensory and motor blockade as volumes as large as 30ml.
References:
1. Reg Anesth Pain Med. 2012; 37:363-5.
2. Anesth Analg 2006; 102:593-7.
A71
USE OF ADDUCTOR CANAL COMPARTMENT BLOCKADE FOR TOTAL KNEE
ARTHROPLASTY: RESULTS OF OUR INSTITUTIONAL OBSERVATIONAL STUDY
A. Vydyanathan, M.V. Tu, R. Maret, B. Kosharskyy, K. Gritsenko, N. Shaparin
Anesthesiology and Pain Medicine, Albert Einstein College of Medicine/Montefiore Medical Center,
New York, NY, USA
Introduction: The use of regional anesthesia following total knee replacement has revolutionized
postoperative pain control and facilitated rehabilitation (1). Femoral nerve blockade has been
traditionally used for this surgery, but one concerning issue is the incidence of quadriceps weakness
in the postoperative period in a subset of patients that delays effective rehabilitation therapy (2).
Recently, adductor canal compartment blockade has been suggested as an effective alternative while
completely sparing any motor involvement (3). We performed this observational study on the use of
adductor canal blockade in total knee arthroplasty.
Methodology: This study is an IRB approved retrospective observational study conducted on patients
between 18-85 years with ASA 3 and below classification who underwent total knee arthroplasty over
the past 3 months and received an adductor canal compartment block for postoperative analgesia in
lieu of femoral blockade. Intraoperative data collected was duration of surgery, type of anesthesia and
tourniquet pressure and duration. Data was collected from POD 0 to POD 2 and included pain
variables (NRS, opioid consumption), physical therapy performance variables (bed mobility and
balance and transfer tests) and any associated complications.
Results: Data was collected on 22 patients. 12 patients received a spinal anesthetic for the surgery
and the rest received a general anesthetic. The duration of surgery was 98.9 ±36.2 min and the
tourniquet time was 56.1±19.4 min. Tourniquet pressure was 350 mm Hg in 17 patients and 275 mm
Hg in 5 patients. The patients received between 20-25 cc of 0.5% Ropivacaine. The NRS on POD 0
was 2.3±3.4 (scale of 1-10) and on POD 1 was 2.6±3.1. The total morphine consumption in first 24
hours was available on 19 patients and was 28.3±9.8 mg iv.
Physical therapy milestones: Restriction of ROM for extension of operated knee was 8.7±9.9 degrees
on POD 1 and 4.8±3.5 degrees on POD 2. Range of flexion of operated knee was 62.2±15.1 degrees
on POD 1 and 70±13.8 degrees on POD 2. The data on quadriceps strength recovery in operated
extremity is given in Graph 1. Achievement of other PT milestones is shown in Graph 2.
[Quadriceps strength recovery against % of patients]
[Number of patients achieving PT milestones ]
Conclusion: Our observational study of 22 patients who received adductor canal blockade for total
knee arthroplasty shows that adductor canal blockade provides effective postoperative analgesia
while causing minimal quadriceps weakness and improves physical therapy milestones.
References:
1. Paul JE, Arya A, Hurlburt L, Cheng J, Thabane L, Tidy A, Murthy Y. Femoral nerve block improves
analgesia outcomes after total knee arthroplasty: a meta-analysis of randomized controlled trials.
Anesthesiology. 2010 Nov;113(5):1144-62.
2. Ilfeld B. Duke K. et al. The association between lower extremity continous peripheral nerve blocks
and patient falls after knee and hip arthroplasty. Anesth Analg. 2010. 111.6: 1552-1554.
3. Jenstrup M, Jaeger P. et. al. Effects of adductor-canal-blockade on pain and ambulation after total
knee arthroplasty: A randomized study. Acta Anaestesiol Scand 2012; 56: 357-364.
A72
A COMPARISON OF INTRAVENOUS AND PERINEURAL DEXAMETHASONE ON SCIATIC
NERVE BLOCKADE
A.M. Weingart, R. Rahangdale, M. Kendall, R. McCarthy, A. Mahil
Anesthesia, Northwestern Memorial Hospital, Chicago, IL, USA
Introduction: When used as an adjunct in brachial plexus blocks, dexamethasone has been shown
1-2
to increase duration of sensory and motor blockade.
Additionally, IV dexamethasone has been
shown to decrease post-operative pain. No prior study has evaluated the analgesic effects of
perineural dexamethasone as compared to IV dexamethasone. The purpose of this study is to
compare the effects of perineural dexamethasone to IV dexamethasone or saline on the quality of
recovery of patients receiving sciatic nerve block for foot and ankle surgery.
Methods: Following IRB approval, written informed consent was obtained in 70 patients, ASA I-III
adults (18-70 y/o) scheduled for foot and ankle surgery to receive an infragluteal parabiceps sciatic
nerve block. Subjects were assigned to one of three study groups by a computer generated table of
random numbers: Group 1: bupivacaine 0.5% with 1:300,000 0.45ml/kg + 2ml perineural
dexamethasone 8mg + IV NS), Group 2: bupivacaine 0.5% with 1:300,000 epinephrine 0.45ml/kg +
2ml NS + IV dexamethasone 8mg in 50ml NS, Group 3: bupivacaine 0.5% with 1:300,000 epinephrine
0.45ml/kg + 2mL NS + 50ml IV NS. Needle positioning was performed using ultrasound guidance. All
IV infusions were for 10 minutes initiated at the time of the block. Block duration was assessed as
patient reported first toe movement. Pain scores, opioid consumption and quality of recovery (QOR40)
were assessed perioperatively.
Results: Seventy subjects were enrolled and 68 completed the study. The duration of the sciatic
block was longer for the groups that received dexamethasone compared to saline (Table). There was
no difference in opioid use among groups. Perineural dexamethasone subjects reported lower pain
score pain scores at 24 hr than the saline group, but opioid consumption was similar among groups.
There was no difference in QOR-40 scores among groups.
Groups
Perineural
dexamethasone
Intravenous
dexamethasone
Saline
Time to first toe
movement (hr)
30.6(25.4-33.2)
24.9(21.8-29.9)
18.2(15-20.1)†
Pain score 24 hr 48 hr
0(0-2)‡ 4(1.5-5)
2.5(0-5) 3(0-4)
4(0-8) 2(1-6)
Opioid consumption
(morphine Eq) 0 to 24 hr 23(15-45) 30(15-45)
24 to 48 hr
34(15-51) 23(11-60)
34(23-45) 30(13-45)
QOR-40 (48 hours
postop)
178(167.5-183.5)
177.5(169-183)
177(170-180)
[Duration of Sciatic Block with Dexamethasone]
Conclusion: The important finding of this study is that both IV and perineural dexamethasone
increase the duration of motor blockade for patients receiving sciatic nerve block for foot and ankle
surgery. Further studies are needed to elucidate mechanisms of action, doses, and the role of
perinueral and systemic dexamethasone for peripheral nerve blocks.
References:
1. Br J Anaesth. 2011 Sep;107(3):446-53
2. Reg Anesth Pain Med 2010; 35 422-6
3. Anesthesiology 2011; 115(3) 575-588
A73
®
SUFENTANIL NANOTAB PCA SYSTEM: PHASE 3 ACTIVE-COMPARATOR DATA VERSUS IV
PCA MORPHINE FOR POST-OPERATIVE PAIN
1
2
3
4
T. Melson , D.L. Boyer , H. Minkowitz , P.P. Palmer , M.A. Royal
1
4
2
Anesthesiology, Helen Keller Hospital, Sheffield, Anesthesiology, Beer Simon and Associates,
3
Florence, AL, Anesthesiology, Memorial Hermann Memorial City Hospital Medical Center, Houston,
4
TX, Clinical, AcelRx Pharmaceuticals, Inc., Redwood City, CA, USA
Introduction: Intravenous patient-controlled analgesia (IV PCA) is commonly used to manage
postoperative pain. However, it is associated with limitations, including programming errors and
reduced patient mobility. Sufentanil is an opioid approved as IV and epidural formulations. While it
possesses a high therapeutic index with minimal respiratory depressive effects relative to its analgesic
effect, high cardiac stability and minimal pharmacokinetic differences based on age, liver or kidney
function, rapid redistribution from plasma following IV administration and short duration make it less
than ideal for IV PCA. The Sufentanil NanoTab PCA System (SNPS) is a novel preprogrammed
noninvasive product in Phase 3 development designed to deliver sublingual sufentanil 15 mcg
microtablets with a 20-minute lockout period. This study was designed to evaluate the ability of SNPS
to produce comparable patient satisfaction with post-operative pain control to IV PCA with morphine 1
mg q6 min lockout (IV PCA). Patient satisfaction with pain management as measured by the HCAHPS
Survey has been identified as a key driver of patient loyalty to a hospital.
Methods: In a Phase 3 randomized, open-label, non-inferiority trial at 26 US sites, adult inpatients
after major open abdominal or orthopedic surgery (knee or hip replacement) were randomized 1:1 to
SNPS or IV PCA for up to 72 hours, stratified by age and type of surgery. The 48-hour Patient Global
Assessment (PGA-48) using a 4-point scale (poor, fair, good, excellent), comparing the proportion of
patients who responded “good” or “excellent” (collectively “success”) in each treatment arm was
defined as the primary endpoint. Pain intensity scores and pain relief scores were obtained as
secondary endpoints. Up to 390 patients were to be enrolled to ensure at least 176 patients per
group, received treatment and had available primary efficacy data for analysis to provide 90% power
to demonstrate therapeutic non-inferiority. A 95% confidence interval (CI) of the difference in success
rate between two treatment groups was constructed and if the lower boundary of this CI was not less
than -15%, SNPS would be considered non-inferior to IV PCA.
Results: 446 patients were screened, 359 were randomized, and 357 received study drug (ITT
population: SNPS [n=177] and IV PCA [n=180]) with one patient in each group who did not receive
study drug. The mean age for the SNPS group was 63.8 years (30.5% males) and IV PCA group was
64.0 yrs (40% males). Knee arthroplasty represented 32% of surgeries in both groups. The primary
efficacy analysis, PGA at 48hr, included 355 patients (176 SNPS and 179 IV PCA). Overall, 78.5% vs.
66.1% of patients achieved PGA 48 “success” for the SNPS group vs IV PCA group, respectively,
demonstrating both non-inferiority based on the 95% CI (p < 0.001 using the one-side Z-test against
the -15% non-inferiority margin) as well as statistical superiority in favor of the NanoTab System
(p=0.009).
Conclusion: The Sufentanil NanoTab PCA System provides an alternative patient-controlled
analgesia modality which is easy for healthcare professionals to set-up and patients to use.
A74
SUBLINGUAL, BUCCAL AND ORAL PHARMACOKINETICS OF THE SUFENTANIL NANOTAB
®
P.P. Palmer, M. Evashenk, M.A. Royal
Clinical, AcelRx Pharmaceuticals, Inc., Redwood City, CA, USA
Introduction: The Sufentanil NanoTab PCA System is a novel preprogrammed noninvasive product
candidate in Phase 3 development that dispenses small (3 mm diameter) sufentanil 15 mcg
microtablets sublingually with a 20-minute lockout period. Sufentanil is an opioid approved as an IV
and epidural formulations. It possesses a high therapeutic index with minimal respiratory depressive
effects relative to its analgesic effect in animal studies, a low incidence of cardiac instability and
minimal pharmacokinetic differences based on age, liver or kidney function. While these attributes
could be ideal in a post-operative opioid analgesic, its rapid redistribution from plasma following IV
administration and short duration of action make it less than ideal for intravenous patient-controlled
analgesia (IV PCA). Two pharmacokinetic (PK) studies were performed to compare sufentanil PK
parameters after sublingual (SL), buccal (BU), oral/gastrointestinal (GI) (PO) and IV routes of
administration. Additionally, a literature review for both sufentanil and fentanyl transmucosal delivery
and comparisons with oral absorption was performed.
Materials/Methods: Two PK studies were performed to evaluate differing oral transmucosal and
oral/GI routes of sufentanil NanoTab delivery. In MPS101, five single-dose treatment arms were
evaluated, however this presentation will discuss only the PK parameters for SL, BU and PO
sufentanil 15 mcg NanoTab administration in comparison to sufentanil IV. In IAP102, a single dose of
the sufentanil 15 mcg NanoTab was administered via SL, BU and PO routes and compared to 15 mcg
sufentanil IV as a slow IV push over 1 minute.
Results: In the MPS101 study, sufentanil bioavailability was 51%, 78% and 7% for the SL, BU and
PO routes, respectively, relative to the commercial IV sufentanil formulation tested. The mean T max for
SL (0.78h) and BU (0.89h) routes were similar, however for PO, it was significantly delayed at 1.24h.
In the IAP102 study, sufentanil bioavailability was 57%, 78% and 6% for the SL, BU and PO routes,
respectively. Similarly, the mean Tmax for BU (1.05h), and SL (0.89h) were similar, whereas the PO
route was significantly prolonged compared to SL at 1.16h. In both studies, the SL route of
administration did not result in a Tmax range beyond 90 minutes.
Conclusion: Sufentanil microtablets show significantly reduced oral bioavailability compared to
sublingual or buccal administration. Swallowed oral sufentanil absorption is approximately 5-fold less
than the oral/GI bioavailability of fentanyl reported in the literature (31%). Avoidance of this delayed
gastrointestinal uptake of drug may be the reason behind the narrow range of T max values observed
for the SL sufentanil NanoTab compared to published T max ranges for oral transmucosal fentanyl
products, which range out to 240 minutes.
A75
THE IMPACT OF TEACHING COURSES ON GAINING ULTRASOUND GUIDED REGIONAL
ANESTHESIA KNOWLEDGE
S. Abbas, A.U. Niazi, J. McVicar, V.W. Chan
Department of Anesthesia and Pain Management, Toronto Western Hospital, Toronto, ON, Canada
Introduction: The popularity of ultrasound guided regional anesthesia (UGRA) has increased over
the past decade. Success in performing ultrasound-guided peripheral nerve blockade demands sound
1
knowledge of sonoanatomy, good scanning techniques, and proper hand-eye coordination. Learning
UGRA can be challenging for novice practitioners. The ASRA Joint Committee recommendations for
education and training in UGRA include participation in educational events that include both didactic
2
and hands-on experience.
We analyzed the pre and post-test evaluations of three basic ultrasound courses to determine how
effective they were for the acquisition of sonoanatomy knowledge.
Materials and methods: Since 2004 the regional anesthesia group at our institution has conducted a
basic ultrasound course once a year. Each course has an average of 40 registrants. The course is
held for three days, the first day includes 8 hours of didactic lectures and the following two days
registrant have sufficient supervised time for hands-on scanning sessions which also includes
needling practice on phantoms. The course participants mainly include anesthetists who have no or
minimal experience in the use of ultrasound in regional anesthesia. Emphasis is mainly given to basic
3
and intermediate ultrasound guided nerve blocks. The course is designed to provide feedback and
pointers on how to improve image quality and scanning technique. Registrants have to complete a pre
& post-test to evaluate their knowledge of basic ultrasound guided blocks. Each test includes 40
questions that cover a variety of ultrasound and regional anesthesia subjects, such as sonoanatomy,
ergonomics, scanning techniques, judgment, recognition of intravenous or intraneural injections and
image optimization. The pre and post evaluations of the course are designed to assess the cognitive
skills of the participants and unfortunately do not assess their manual skills.
Results: We report the pre and post results of three, basic UGRA courses conducted at our
institution. In total there were 120 participants, 78 % were beginners (< 20 blocks), 19% were
intermediate (20-50 blocks) and only 1% were advanced (51-100 blocks). The average pre-course
test score was 72.8% ±2 with a standard deviation of 18.8 and the average post-course test score
was 91.26 ±1 with a standard deviation of 10.9.
Discussion: Although workshops are resource intensive means to teach sonographic anatomy they
remain an effective tool to teach ultrasound device operations and image generation, optimization and
interpretation. The findings of this study support the practice pathway recommendations of the
2
ASRA/ESRA joint committee.
References:
1. Sites BD, Chan VW, Neal JM, et al. The American Society of Regional Anesthesia and Pain
Medicine and the European Society of Regional Anaesthesia and Pain Therapy Joint Committee
recommendations for education and training in ultrasound-guided regional anesthesia. Reg Anesth
Pain Med. 2009;34:40-46.
2. Niazi AU, Haldipur N, Prasad AG, Chan VW. Ultrasound-guided regional anesthesia performance
in the early learning period: effect of simulation training. Reg Anesth Pain Med. 2012 JanFeb;37(1):51-4.
3. Hargett MJ, Beckman JD, Liguori GA, Neal JM Guidelines for regional anesthesia fellowship
training. Reg Anesth Pain Med. 2005 May-Jun;30(3):218-25.
Funding disclosure: None to disclose.
Personal conflicts of interest disclosure: Consultant (GE Healthcare).
A76
PAIN RELIEF FOLLOWING THORACOSCPIC SYMPATHECTOMY FOR PALMAR
HYPERHYDROSIS
A. Abdulmomen
Anesthesia, King Saud University, Riyadh, Saudi Arabia
Background: Acute pain management following thoracoscopic sympathectomy (TS) has been
described in the literature. The combination of interpleural (IP) injection of bupivacaine and
intramuscular injection. (I.M) NSAIDs has not been reported. Therefore we conducted this randomized
controlled trial to compare this technique to other reported techniques described for postoperative
analgesia following TS.
Methods: 40 patients scheduled to have TS under general anesthesia for the treatment of
hyperhidrosis were randomly allocated into 4 groups. Group 1 received 1.5 mg/kg b.w I.M pethidine at
end of surgery. Group 2 received ketoprofen 100 mg I.M at end of surgery. Group 3 received 0.4
ml/kg b.w interpleural bupivacaine 0.5%. Group 4 received a combination of I.M ketoprofen (100 mg)
in addition to interpleural bupivacaine (0.4 ml/kg). Postoperative pain was assessed using the 11point numeric rating score (NRS) at 7 different intervals. First, immediately on admission to PACU,
every 2 hours for the next 8 hours then at 12 and at 24 hours. Pain was assessed at rest, during deep
inspiration and while coughing. ANOVA was used for statistical analysis and Chi-square test for
comparing of the data where P values < 0.05 were considered significant.
Results: The NRS at rest was 3.2 (1.9), 2.4 (1.6), 3 (1.9) and 0.7 (0.9) at Groups 1, 2, 3 and 4
respectively with significant difference in Group 4 versus other Group (P< 0.05) at 2 hours
postoperatively and up to 24 hours postoperatively. The same trend was also found during
maximal inspiration and while coughing. Opioid consumption in 24 hours was significantly reduced in
Group 4 compared to other Groups.
Conclusions: Combination of IP bupivacaine and I.M ketoprofen provided superior analgesia when
compared to each modality alone and was better than intramuscular pethidine injection in terms of
NRS and the consumption of rescue morphine postoperatively. Further studies are needed on large
sample size to confirm our results.
A77
THE ANALGESIC EFFICACY OF ULTRASOUND-GUIDED PARAVERTEBRAL BLOCKS IN
VIDEO-ASSISTED THORACOSCOPIC SURGERIES: A RETROSPECTIVE ANALYSIS
C. Amlong, M. Donnelly, C. Warren, M. Ford
1
2
Department of Anesthesiology, University of Wisconsin Hospital and Clinics, Illumivista Biosciences,
Madison, WI, USA
Introduction: Video-assisted thoracoscopic surgeries (VATS) have increased in popularity among
thoracic surgeons. The advantages of a VATS procedure include decreased postoperative pain,
improved cosmetic surgical wounds, lower morbidity, and shorter hospital stays when compared to
1
open thoracic procedures. Paravertebral blocks (PVBs) are a validated method of limiting post2
operative pain for patients undergoing VATS and other thoracic procedures. Our institution began
providing ultrasound-guided PVBs for patients undergoing VATS in spring of 2011 with positive
feedback from both patients and surgeons. The current study was performed to provide objective data
pertaining to the analgesic efficacy of these blocks in patients undergoing VATS.
Methods and materials: Following IRB approval, the charts of 44 consecutive patients receiving
VATS performed by a single thoracic surgeon between 1/26/11 and 9/28/11were reviewed. Charts of
40 patients were included in the study. Of these, 18 received a preoperative, ultrasound-guided PVB.
Patient opioid requirements were recorded from the various perioperative periods, including
intraoperatively; in the post-anesthesia care unit (PACU); for the 24-hour period following PACU
discharge; and for the patient's entire postoperative hospital stay. These values were converted to
intravenous morphine equivalents to facilitate comparison. Patient-reported numerical pain scores (010) from the PACU, the 24-hour postoperative period and from the patients' entire postoperative
hospital course were also recorded. Episodes of treated perioperative nausea or vomiting were noted,
as was duration of stay in the PACU.
Results: We examined 13 perioperative outcomes including opioid administration, pain scores, and
nausea in the various perioperative periods as well as duration of PACU stay. Although 12 of 13
studied outcomes demonstrated a trend towards an improved recovery profile in the PVB group, only
PACU immediate pain score and intra-operative opioid usage were statistically significantly lower
(p=0.048 and 0.014, respectively). While only 2 of these outcomes show statistical significance, the
odds of 12 of 13 outcomes showing a favorable trend towards PVBs is highly statistically significant
(p< 0.001).
Discussion: The current study suggests an improved recovery profile in patients who underwent
VATS surgery with a preoperative ultrasound-guided PVB compared to those that did not receive a
block. Although our study is underpowered, the resultant trends are consistent with other published
research examining the efficacy of landmark driven PVBs. We plan to further study the analgesic
efficacy of ultrasound-guided PVBs to validate their usefulness at our institution and perhaps
demonstrate improved efficacy with the use of ultrasound guidance.
References:
1. Grogan EL, Jones DR. VATS lobectomy is better than open thoracotomy: what is the evidence for
short-term outcomes? Thorac Surg Clin. 18:249-258. 2008.
2. Hill SE, Keller RA, Stafford-Smith M et al. Efficacy of single dose, multi-level paravertebral nerve
blockade for analgesia after thoracoscopic procedures. Anesthesiology. 104:1047-1053. 2006.
A78
ARE WE BLOCKING COMPARTMENT SYNDROME? INCIDENCE OF UPPER EXTREMITY
COMPARTMENT SYNDROME AFTER REGIONAL ANESTHESIA
R. Baig, L. Foster, M. Matuszczak, R. Jain
1
2
University of Texas Medical School-Houston, Anesthesiology, University of Texas Medical SchoolHouston, Houston, TX, USA
Background: Compartment syndrome is an infrequent, yet devastating complication of extremity
traumas in children. Supracondylar fractures of the upper extremity are thought to carry the risk of
compartment syndrome [1]. Increasing analgesic requirement is shown to be an early indicator of
compartment syndrome [2]. This presents a challenge in treatment, as many surgeons are hesitant to
allow regional anesthesia for fear of masking early stages. While there are case reports attributing a
delay in compartment syndrome diagnosis to regional anesthesia, there is a lack of published data on
incidence. The purpose of this study is to identify the incidence of compartment syndrome after
regional anesthesia is performed for postop pain control in pediatric upper extremity injuries.
Methods: With IRB approval all our blocks are prospectively entered into the Pediatric Regional
Anesthesia Network database. From our PRAN data we evaluated 209 upper extremity blocks
performed in pediatric patients from May 2010 to September 2012 at Memorial Hermann Children's
Hospital. Patients were followed by the pain service for complications. Data obtained were reviewed
for incidence of compartment syndrome.
Results: Of 209 upper extremity blocks performed, 98 were in patients with supracondylar fractures
of the humerus. The most common cause of supracondylar fracture was a fall. The majority of blocks
placed were axillary single shot with ropivicaine, but also included infraclavicular and supraclavicular
blocks. All blocks were ultrasound guided. There was zero incidence of compartment syndrome or
block complication noted.
Discussion: The incidence of compartment syndrome after regional anesthesia for postop pain
control in upper extremity fractures in our case series is zero. There are several limitations: lack of a
denominator, possible avoidance of regional anesthesia for more severe trauma, surgical bias against
regional anesthesia, insufficient power. There is a lack of evidence in the literature that regional
anesthesia delays diagnosis of compartment syndrome provided close follow-up [3]. More data is
needed so that fear is not the reason to deny appropriate pain control to children.
References:
1. Dalens, B. Some current controversies in pediatric regional anesthesia. Curr Opin Anaesthesiol
2006; 19:301-308.
2. Bae DS, Kadiyala RK, Waters PM. Acute Compartment Syndrome in Children: Contemporary
Diagnosis, Treatment, and Outcome. J Pediatr Orthop 2001; 21:680-688.
3. Mar GJ, Barrington MJ, Mcguirk BR. Acute compartment syndrome of the lower limb and the effect
of postoperative analgesia on diagnosis. Br J Anaesth. 2009;102 (1): 3-11.
A79
PRE-OPERATIVE PAIN MANAGEMENT CONSULTATION DOES NOT IMPROVE POSTOPERATIVE PAIN IN OPIOID-TOLERANT PATIENTS
J.C. Bailey, B.L. Ladlie, S.A. Candler, J.M. Irizarry, M. O'Brien
1
2
3
Anesthesiology, Pain Management, Pre-operative Exam Clinic, Mayo Clinic, Jacksonville, FL, USA
Introduction: Despite higher doses of opioid medications administered to opioid tolerant patients, this
patient population continues to have higher pain scores and a higher incidence of sedation than
1
opioid naive patients in the post-operative period . Pain in opioid tolerant patients is also much slower
2
to resolve . In an effort to improve post-operative analgesia in opioid tolerant patients, we
incorporated an evaluation by an expert pain consultant in the pre-operative clinic. All patients on
long-acting opioids were eligible for consultation. Post-operative analgesic recommendations were
made prior to surgery and were initiated immediately post-operatively. Our hypothesis was that
patients seen pre-emptively would have improved pain scores. We also proposed that they would be
more likely to receive larger opioid amounts overall and be more likely to receive multi-modal
analgesia. This study represents a case-control synthesis of data obtained during the six month
period when pain consultation was available in the pre-operative clinic.
Material and methods: Patients selected to be evaluated pre-operatively by the chronic pain team
were identified through analysis of preoperative opioid requirements in their electronic medical record.
The medical record was reviewed for demographic information, pre-operative pain scores, postoperative pain scores, medications and dosages, and type of surgery. Controls were then identified
again through EMR data as patients on chronic opioids who did not receive expert consultation preoperatively. The cases and controls were matched based on their pre-operative opioid consumption,
in daily morphine equivalents. All opioid conversions were completed using the advanced opioid
converter on the globalrph.com website.
Results: On average, patients receiving a pre-operative pain consult had a daily pain score greater
than their case controlled counterpart on each of the first three post- operative days. Also during this
time, the patients receiving a pain consult had a pain score greater than 4 on average greater than
50% of the time compared to the patients who did not receive a consult. The patients receiving a pain
consult also had a 30% increase in total cost of hospital stay compared to patients who did not
receive a consult. It was noted however that the cost of medications during the hospitalization for
patients receiving a pain consult was slightly decreased.
[Graph 1]
Discussion: Our data fails to show that obtaining a preoperative pain consult improves post-operative
pain scores. As expected, the average cost of hospitalization for the patients who received a pain
consult was increased. Since this is a small retrospective case-control study (n=15), it is difficult to
draw conclusions from this data, however, there is no evidence that pre-operative pain management
consultation improves analgesia in opioid tolerant patients.
References:
1. Rapp, SE, LB Ready, ML Nessly. Acute pain management in patients with prior opioid
consumption: a case-controlled retrospective review. Pain (1995) 62; 195-201.
2. Chapman CR, Donaldson G, Davis J, Ericson D, Billharz J: Postoperative pain patterns in chronic
pain patients: A pilot study. Pain Med (2009) 10; 481-487.
Funding: None
Pain Consult
No Consult
Total
n=15
n=15
Age
60
68.3
Male
0.53
0.20
Extremity Surgery
5
9
Abdominal/Pelvic Surger
1
1
Thoracic Surgery
1
1
Skin/Soft Tissue Surgery
1
2
Endoscopic Surgery
0
2
Neuro/Spine Surgery
7
0
[Table 1]
A80
THE USE OF GASSERIAN GANGLION BLOCK IN NEOPLASTIC TRIGEMINAL NEURALGIA - A
CASE SERIES
S. Srinivasan, M. Issa, S. Narang, D. Boyce
Anesthesiology, Brigham and Women's Hospital, Boston, MA, USA
Introduction: Trigeminal neuralgia related to cancer may result from local compression of the nerve
or local release of inflammatory cytokines, and is usually poorly responsive to medical management
(1). We report a series of four patients who achieved prolonged analgesia with repeated gasserian
ganglion injections of local anesthetic combined with methylprednisolone.
Methods and materials: Four patients with advanced head and neck cancer resulting in intractable
trigeminal neuralgia poorly responsive to conservative medical management were treated with
gasserian ganglion blocks performed by the extra oral approach. A 22-gauge spinal needle was
inserted in a medial, posterior and caudal fashion into the foramen ovale area, with fluoroscopic
guidance. The needle was imaged periodically in antero-posterior and lateral views and 0.5 mL of
contrast dye Omnipaque 180 mg/ml was injected to confirm accurate location. Next, 40 mg of
methylprednisolone and 4 ml of 0.25% bupivacaine was injected in gradual increments with
continuous fluoroscopic guidance. The injections were well tolerated in all four cases without any
complications. The block was repeated when symptoms returned.
Results: The patients received from one to three blocks, and were benefited for 2 to 6 weeks. The
use of pain medication decreased in three patients. All patients had 50% or more relief, and 2 patients
reported over 80% benefit for the time period. No complications were reported in the patients. (See
table)
Type of cancer
Number of
Blocks
Duration of
pain relief
Reduction in
pain
medication
Percent relief
Complications
Patient 1
Squamous Cell
Carcinoma
1
3 weeks
Yes
50%
None
Patient 2
Squamous Cell
Carcinoma
2
2 weeks
No
50%
None
Patient 3
Parotid
3
Adenocarcinoma
2 to 6 weeks
Yes
80%
None
Patient 4
Squamous Cell
Carcinoma
2 to 6 weeks
Yes
80%
None
[Table 1]
3
[Fig 1]
[Fig 2]
Conclusion: Treating patients with advanced head and neck cancer may be very challenging in
clinical practice. In this case series, we present information regarding the effectiveness and safety of
gasserian ganglion blocks in a small series of patients with intractable neoplastic trigeminal neuralgia.
We concluded that our patients had satisfactory relief with gasserian ganglion blocks emphasizing the
safety and effectiveness of nerve blocks in cancer related pain of this nature.
Reference:
1. Cheng T, Cascino T, Onofrio B. Comprehensive study of diagnosis and treatment of trigeminal
neuralgia secondary to tumors. Neurology. 1993 Nov;43(11):2298-302
A81
A RANDOMIZED COMPARATIVE EVALUATION OF TWO APPROACHES FOR POSTERIOR
LUMBAR PLEXUS BLOCK USING REAL TIME ULTRASOUND GUIDANCE - A PILOT STUDY
1
1
1
2
J. Brookes , S. Ganapathy , R. Sondekoppam Vjayashankar , S. Adhikary , L. Subramanian
1
1
2
University of Western Ontario, Anesthesia, University of Western Ontario, London, ON, Canada,
Milton S Hershey Medical Centre, Hershey, PA, USA
3
Introduction: Lumbar plexus block (LPB) is a well accepted method for post operative analgesia in
patients undergoing lower limb surgery. Karmakar et al reported an approach using an paramedian inplane ultrasound probe in a case series of 5 patients. They found it impossible to visualize the whole
path of the needle while using real-time ultrasound due to the plexus depth and steep angle of
insertion.
Capdevila et al described an approach contacting the transverse process and advancing inferior to it.
We add off-plane ultrasound guidance to this approach to position the needle on the transverse
process with the probe in transverse axis. Adding USS allows visualization of needle tip location with
hydro-location and estimation of depth of deeper structures.
Methods: 19 patients undergoing total knee arthroplasty were randomized to receive one of the two
approaches. We hypothesized that off-plane needle insertion for lumbar plexus would be quicker and
woulf result in higher success rate compared to an in-plane approach. Block onset was checked every
5 minutes for 30 minutes. Pain scores were collected for 48 hours. Patients were followed up at one
week.
Results: 19patients underwent randomization. Demographic data were similar between groups:
In plane
Off plane
ASA status (I,II,III)
(1,5,4)
(0,3,6)
BMI - mean (SD)
28 (5.4)
30 (3.3)
Height - mean (SD) 165 (8.0)
170.6 (11.5)
[Demographics]
Visualization of the lumbar plexus and adjacent structures while in-plane could be clear but was
frequently challenging, requiring 40% of the in-plane blocks to be converted to off-plane.
[In plane]
Visualization of the transverse process could usually be seen in the off-plane transverse approach.
[Off plane]
There were no significant difference in procedure times, block success rates or postoperative verbal
reported pain scores (VRS) between the two groups. No adverse events occurred.
Procedure details:
In plane
Off plane
P
666 (444)
622 (237)
0.81
Crossover rate (n/group
4/10
total)
0/9
0.087
Block
complete/incomplete
(sensory and motor) at
30 minutes (n)
3/6
2/4
>0.99
Block
complete/incomplete
4/5
(sensory) at 30 minutes
(n)
3/3
>0.99
Block
complete/incomplete
(motor) at 30 minutes
(n)
2/4
>0.99
Procedure time:
mean(SD)
[Procedure details]
3/6
Pain outcomes:
In plane
Off plane
P
mean(SD) VRS at rest/
on movement 12hrs
2.8(3.7)/4.1(4.0)
2(8.2)/4(3.9)
0.62/0.95
mean(SD) VRS at rest/
on movement 24hrs
2.2(3.0)/3.8(3.0)
1.8(2.6)/3.9(2.9)
0.74/0.94
mean(SD) VRS at rest/
on movement 36hrs
1.25(1.6)/2.5(2.1)
2(1.9)/3.4(1.7)
0.39/0.33
mean(SD) VRS at rest/
on movement 48hrs
1.5(1.5)/4.8(3.4)
1.2(1.1)/3.0(0.9)
0.67/0.16
[Pain outcomes]
Discussion: Visualization of anatomical structures was frequently difficult. Despite this pain scores
were low. Due to the steep needle angle and plexus depth, visualization of the needle tip is likely to
remain a challenge in a significant proportion of patients. The off-plane approach can be viewed as a
useful extension of the nerve-stimulator technique.
Funding: None.
Personal conflicts of interest disclosure: Nothing to disclose.
A82
BUPIVACAINE EXACERBATES FACIAL MOTONEURON (FMN) AXOTOMY-INDUCED CELL
DEATH
S. Byram, S. Byram
Loyola University Chicago, Maywood, IL, USA
The appropriate management of pain after an injury or surgical procedure has been shown to improve
the outcome of patients by quickening recovery and reducing hospital costs. Anesthesiologists
commonly use local anesthetics (LA) to perform nerve blocks that result in temporary pain control
during or after a surgical procedure. While infrequent, nerve damage resulting from regional
anesthesia can be devastating, and the exact mechanism of injury remains unknown. The
1-4
neurotoxicity of LA has been well documented . LA have been shown to cause growth cone
1-4
inhibition and neuron death, demyelination, and infiltration of inflammatory cells . Because LA are
frequently applied to sites where peripheral nerves may be growing (e.g., chemical, burn, mechanical
injury or neurodegenerative disease), their effects on growing neurons should not be ignored in
clinical practice. There are no current studies in the literature that examine the effects of LA on
diseased or injured nerves, a commonly encountered clinical scenario. The purpose of this study was
to determine if LA exacerbate FMN axotomy-induced cell death. C57B/6 mice were subjected to a
right facial nerve axotomy, with the left (uninjured) side serving as control. At the time of axotomy we
placed gelfoam impregnanted with 1) saline, 2) 2% lidocaine or 3) 0.75% bupivacaine. The brains
were removed 4 -weeks post-axotomy, frozen, and 25 mm cryostat sections collected through the
facial nucleus and thionin stained. FMN were counted, and a ratio between cut and uncut FMN
calculated. The average percent FMN survival in mice treated with saline (control group) 4 weeks
5
after facial nerve axotomy was 80%, which is similar to previously published data . The average
percent FMN survival in mice treated with lidocaine was 78%, which is not significantly different,
compared to the saline control group. The average percent FMN survival in mice treated with
bupivacaine was 35%, a significant decrease of 45% in FMN survival relative to the saline treated
control group.
[Percent FMN Survival]
Our data suggest that bupivacaine placed on a transected nerve stump at the time of injury
exacerbates FMN cell death. It has been proposed that once a nerve is damaged, it becomes more
6
susceptible to injury elsewhere along the nerve . For example, patients with diabetic neuropathy have
a higher incidence of nerve entrapments, and a cervical radiculopathy stemming from the neck
6
increases the likelihood of carpal tunnel syndrome . Furthermore, there is ample literature debating
the safety of sciatic nerve blocks for knee replacement surgery, given the 20% incidence of sciatic
nerve injury from the surgery itself and therefore the risk of double crush phenomenon. Thus, an
improved understanding of the effects of LA on neurons may lead to strategies to identify patients at
higher risk for permanent neural deficits after peripheral nerve blocks and/or decrease the risk of
neural deficit following peripheral nerve blocks.
Scott Byram - Cadence Pharmaceutical speaker bureau
1
2
3
4
Werdehausen et al., 2009; Radwan et al., 2002; Perez-Castro et al., 2009; Kalichman et al., 1989;
6
Byram et al., 2004; Upton and McComas 1973
5
A83
A FIVE-DAY MEDICAL STUDENT REGIONAL ANESTHESIA CURRICULUM
T. Caggiano, C. Guheen, M. Kalsi
1
2
Anesthesia, Hospital for Special Surgery, Anesthesia, Hospital for Special Surgery, Weill Medical
College of Cornell University, New York, NY, USA
Introduction: Residencies and careers in anesthesiology have generated increasing interest among
medical students over the past several years. Most medical school curricula offer minimal exposure to
the specialty; furthermore, this exposure is often focused on general anesthesia. Experience and
understanding of airway management is the primary goal of most medical students during these
clerkships. Quite often, exposure of medical students to regional anesthesia is minimal or completely
absent. The primary reason for this is that many departments have difficulty providing opportunities in
regional anesthesia for their residents, let alone medical students.
The Department of Anesthesiology at Hospital for Special Surgery (HSS) is affiliated with Weill Cornell
Medical College and hosts medical students for 1 week of their 4-week clerkship in anesthesia. We
are an orthopedic specialty hospital that performed 34,779 OR cases in 2012 with 12,051 acute pain
procedures. In keeping with our departmental mission to continually foster interest, growth and
education in regional anesthesiology, we have created a five-part medical student curriculum to
facilitate achievement of such goals during the medical student's five-day experience.
The 5-day curriculum for medical students highlights the fundamentals of regional anesthesia and
acute pain medicine. Our goal was to choose appropriate topics for medical students that would
introduce them to the subspecialty and potentially increase their interest in career development of
both anesthesiology and regional anesthesia.
Methods: The authors reviewed multiple general anesthesia textbooks, specialty texts in regional
anesthesia and landmark articles to formulate the background for the curriculum. In addition, the
authors had lengthy discussions with attending staff, fellows, residents and medical students to
determine which topics were of utmost importance to include and emphasize upon.
Results: This five-part curriculum, designed to coincide with the five days of the medical student
rotation here at HSS, contains daily learning objectives, assigned readings, daily questions and
cases, key concepts and relevant images.
A84
PRELIMINARY EXPERIENCE WITH THE COMBINATION OF THROMBOPROPHYLAXIS WITH
RIVAROXABAN FOR DEEP AND SUPERFICIAL BLOCKS
J.E. Chelly, D. Schilling
Department of Anaesthesiology and Pain Medicine, University of Pittsburgh Medical Center,
Pittsburgh, PA, USA
Introduction: Rivaroxaban is a new oral Xa inhibitor approved for thromboprophylaxis in orthopedics.
The risk of major bleeding associated with the combination of thromboprophylaxis with rivaroxaban
and deep and superficial blocks is unknown. This report details our initial experience with the
combination of thromboprophylaxis with rivaroxaban and deep and superficial blocks.
Method: All patients undergoing classic and minimally invasive total hip and total knee replacement
with continuous nerve blocks and receiving rivaroxaban for thromboprophylaxis were included in this
analysis. Blocks were performed prior to surgery (a continuous lumbar plexus for total hip
replacement and a continuous femoral and gluteal sciatic for total knee replacement). Rivaroxaban 10
mg daily was started the day following surgery. The perineural catheters were removed on
postoperative day 1 (hip) and postoperative day 2 (knee) without consideration for the time of
administration of rivaroxaban. Following the removal of catheters patients were monitored for clinical
symptoms of major bleeding.
Results: A total of 21 patients including 6 total hip replacement and 15 total knee replacement
benefited from the combination. No significant bleeding was recorded.
Discussion: Although this represents a very small series and this group recognized that additional
data are required; this represents the only data available on the combination of the combination of
thromboprophylaxis with rivaroxaban and deep and superficial blocks. Like with other drugs used for
thromboprophylaxis the estimated risk of major bleeding of the combination of thromboprophylaxis
and deep and superficial blocks is unknown it is important to recognize that the administration of
rivaroxaban has been associated with major bleeding including a retroperitoneal hematoma. Since
evidence support the value of continuous nerve blocks for joint replacement our data do not suggest
that thromboprophylaxis with rivaroxaban should not be consider at this point a contra-indication of
performing continuous deep and superficial blocks.
References:
1. Dentali F, Riva N, Crowther M, Turpie AG, Lip GY, Ageno W. Efficacy and safety of the novel oral
anticoagulants in atrial fibrillation: a systematic review and meta-analysis of the literature. Circulation.
2012 ;126:2381-91
2. Turpie AG, Lassen MR, Davidson BL, Bauer KA, Gent M, Kwong LM, Cushner FD, Lotke PA,
Berkowitz SD, Bandel TJ, Benson A, Misselwitz F, Fisher WD; RECORD4 Investigators. Rivaroxaban
versus enoxaparin for thromboprophylaxis after total knee arthroplasty (RECORD4): a randomized
trial. Lancet. 2009 ; 373:1673-80
A85
VALIDATION OF AN IN-LINE INJECTION PRESSURE MONITOR USING A REFERENCE DIGITAL
PRESSURE RECORDER
1
1
1
2
3
4
1
J. Choi , E. Lin , J. Gadsden , C. Vandepitte , P. Gautier , I. Hasanbegovic , A. Robinson , X. Sala5
Blanch
1
2
3
St. Luke's Hospital Center, St. Luke's-Roosevelt Hospital Center, Columbia University College of
4
5
Physicians & Surgeons, New York, NY, USA, University Hospitals Leuven, K.U.L., Leuven, Clinique
6
Ste Anne-St Remi, Brussel, Belgium, University of Sarajevo, Sarajevo, Bosnia-Herzegovina,
7
University Hospital Barcelona, Barcelona, Spain
Introduction: Injection pressure monitoring (IPM) has been suggested as a means to detect needlenerve contact and/or intrafascicular injection (1, 2). A disposable in-line IPM (BSmart, Concert
Medical, Norwell, MA) has been gaining acceptance as a clinical tool for injection monitoring.
However, no study has validated its performance against a digital reference standard (DRS). In this
study, we tested the accuracy of BSmart to detect needle-nerve contact using a DRS as a control in
fresh human cadavers.
Methods: This study was approved by the IRB of KU Leuven, Belgium. Needles were inserted using
US to contact and slightly displace the C5, C6, C7 nerve roots in fresh frozen cadavers. Pressure was
slowly applied manually to the syringe (20 mL) until spread of injectate was observed by a blinded
investigator. Pressure data was recorded simultaneously with an in-line IPM (BSmart) and a digital
pressure transducer (PendoTECH, Princeton, NJ) through a 150 cm low-compliance conduit (LectroCath, Vygon, Ecouen, France) and a 22 gauge blunt-tipped stimulating needle (Stimuplex-A, B Braun,
Inc), Figure 1.
[Injection Pressure Apparatus Setup]
Results: Pressures reported by BSmart correlated well with recordings by electronic pressure
transducer. The BSmart monitor continuously displayed pressures through color-coded indicators
(White: 1 to 15 psi; Yellow: 15 to 20 psi; and Red: >20 psi). The BSmart manometer detected all
instances (100%) of opening injection pressure >20 psi recorded by the digital pressure transducer
with needle-nerve contact, Table 1.
BSmart Pressure Monitor
Digital Pressure Transducer (psi)
Cadaver 1 (n = 18)
Red (>20 psi)
28.58 (range: 26.03-30.50)
Cadaver 2 (n = 18)
Red (>20 psi)
32.81 (range: 29.42-34.95)
[Needle-Nerve Contact Opening Injection Pressure]
Discussion: Under the conditions of our study, all attempted injections with needle-nerve contact in
cadavers generated opening injection pressures >20 psi. BSmart accurately detected injection
pressures >20 psi in all instances.
References:
(1) Reg Anesth Pain Med 2012;37:525-529, (2) Acta Anaesthesiol Scand 2007; 51:101-107.
A86
FACILITATION OF ULTRASOUND-GUIDED REGIONAL ANESTHESIA USING A HEADMOUNTED VIDEO DISPLAY - AN EMERGING TECHNIQUE?
R. Przkora, P.J. Courtney, D. Solanki
Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
Introduction: Regional Anesthesia and Analgesia (RA) are established techniques in Anesthesiology.
The best approach to administer RA is still under discussion; however, ultrasound-guidance during
needle placement appears to be the preferred standard of care.
While ultrasound-guidance improved outcomes in RA, its use is not without problems, especially in
regard to the coordination between the hands (ultrasound probe and needle) of the provider and the
display of the ultrasound screen in the distance, requiring head and hand adjustments of the provider.
This problem results in: Frequent needle redirections, repeated skin punctures, increased time to
perform the procedure, increased discomfort for the patient and provider and finally, increased risk of
adverse events.
The close display of the ultrasound-screen in front of the provider`s eyes using special glasses could
improve this situation.
Materials and methods: We used a commercially available head-mounted video display (HMD), a
binocular image monitor worn like regular glasses (video eyewear). The HMD was connected to the
ultrasound screen, displaying the ultrasound image on the monitors in front of the provider`s eyes.
After IRB approval from our institution (UTMB), the HMD was introduced in our clinical practice.
Results: The HMD has been used successfully in over 10 patients requiring RA of the upper or lower
extremities. No complications have been noted during this initial evaluation period.
[Head-mounted video display (HMD) - front]
Conclusion: We introduced for the first time the use of the HMD technique for ultrasound-guided RA
in clinical practice. Studies with patients are currently conducted to evaluate if the HMD improves
coordination compared to the conventional ultrasound-guided approach.
A87
AN INEXPENSIVE AND EASILY-MADE PHANTOM MODEL FOR TRANSVERSUS ABDOMINIS
PLANE (TAP) BLOCK TRAINING AND ASSESSMENT
C.A. Czeczok, K. Schroeder
University of Wisconsin, Madison, WI, USA
Introduction: In the recent past, ultrasound imaging use for regional nerve blocks has become
increasingly popular. Transversus abdominis plane (TAP) blocks are also increasing in popularity
given both their effectiveness in producing post-operative analgesia and the short amount of time
needed to place these blocks. Training tools are necessary for learning how to obtain the images and
effectively place these blocks in the correct tissue plane, and there is a lack of an inexpensive training
model.
Methods: In creating a TAP block phantom model for ultrasound-guided training, we utilized
inexpensive and easily obtainable materials. Materials included a plastic container, gelatin, psyllium
fiber, fruit roll-ups, and olive oil. The tissue mimic was made with 250ml of boiling water mixed with
20g of unflavored gelatin and 10g of sugar-free psyllium fiber. The fascial plane was created with two
fruit roll-ups placed together with a thin film of olive oil between. A Sonosite M-Turbo® ultrasound
machine with a 13.6 MHz linear probe used to obtain images. Two neurostimulating needles were
used to administer normal saline. Both insulated (Arrow StimuQuik®) and non-insulated (Pajunk®)
needles were used; each was 22ga x 50mm.
Results: Ultrasound images obtained from the gel phantom training model, both pre- and postadministration of saline solution, very closely mimicked those found in an adult human. Pre-injection,
out-of-plane injection, and in-plane injection images are seen below.
Discussion: Described above is an inexpensive, easily-made gel phantom model that can be used
for ultrasound-guided TAP block training. This provides training that is accurate, efficient, and safe for
patients.
A88
SEDATION WITH TARGET-CONTROLLED PROPOFOL INFUSION DURING OPEN REDUCTION
AND INTERNAL FIXATION OF HIP FRACTURE IN ELDERLY PATIENTS UNDER ULTRASOUND
GUIDANCE LPB VERSUS CLSB
Z. Da-Qiang, X. Tao, J. Wei
Department of Anesthesiology, Shanghai Jiaotong University Affiliated Sixth People's Hospital,
Shanghai, China
Background and Objective: Patients undergoing open reduction and internal fixation of hip fracture
usually are elderly and present with different associated comorbidities. Studies have demonstrated
the increased risk of mortality after hip fracture especially during the first year, and excess mortality
risk may persist for several years after fracture.It was identified that lumbar plexus block and
combined lumbar plexus and sacral plexus block could be well performed during open reduction and
internal fixation of hip fracture. The aim of this study was to assess target-controlled propofol infusion
as a technique of anaesthesia for open reduction and internal fixation of hip fracture in elderly patients
under ultrasound guidance lumbar plexus block(LPB) or combined lumbar plexus and sacral plexus
block(CLSB); and to evaluate which nerve block was superior for this surgery, lumbar plexus block or
combined lumbar plexus and sacral plexus block.
Methods: Sixty patients(>70 years old)with American Society of Anesthesiologists (ASA) physical
status of 1-3,undergoing scheduled for open reduction and internal fixation of hip fracture received
LPB with 30 ml 0.5% ropivacaine at level L3-4 (LPB group, n=30) or CLSB with 30 ml 0.5%
ropivacaine at level L3-4 and 10 ml 0.5% ropivacaine at sacral plexus (CLSB group, n=30). The
target-controlled propofol infusion was started immediately after positioning the patient on the
operating table. The initial target concentration was 1.5 µg/mL. The infusion rate was adjusted every 5
,
min by increasing or decreasing the target concentration by 0.2 µg/mL steps based on the patients
blood pressure (BP), heart rate (HR), and bispectral index (BIS)and conscious state (score of 1 on
OAA/S sedation scale). The performance time of nerve block, minimal, maximal, optimal target
concentration,respiratory and haemodynamic parameters, total propofol dose, additional fentanyl
needs ,frequency of spontaneous movement and incidences of associated complications were
recorded.
Results: The performance time was shorter in the LPB group than in the CLSB group（274.00±80.54
Vs 348.50±57.88s, P=0.000）. Minimal, maximal, optimal target concentration were significantly
different in the LPB and CLSB groups（1.50±0.05µg/ml vs 1.38±0.13µg/ml, P=0.006;2.06±0.27µg/ml
vs 1.67±0.16µg/ml, P=0.000; 1.97±0.28µg/ml vs 1.57±0.23µg/ml, P=0.000）. There was no significant
difference in respiratory and haemodynamic parameters, total propofol dose between the LPB group
and the CLSB group.The additional fentanyl needs and frequency of spontaneous movement in LPB
group were more than that of CLSB groups.No other associated complications occurred.
Conclusion: Target-controlled propofol infusion as a technique of anaesthesia for open reduction and
internal fixation of hip fracture in elderly patients under ultrasound guidance lumbar plexus block(LPB)
or combined lumbar plexus and sacral plexus block(CLSB) is safe and efficacious. In addition,
combined lumbar plexus and sacral plexus block(CLSB) is more sufficient for hip fracture surgery than
lumbar plexus block.
A89
ASSOCIATION OF ACUTE POST-OPERATIVE PAIN WITH COMT FUNCTIONAL VARIATION IN
PATIENTS AFTER TOTAL KNEE ARTHROPLASTY (TKA)
1
2
2
2
1
2
2
F. Dai , J. Chelly , C.M. Greco , K.L. Vulakovich , L. Qin , D. Landsittel , L. Crossett , I. Belfer
1
2
2
Yale Center for Analytical Sciences, New Haven, CT, Department of Anesthesiology, University of
3
4
Pittsburgh, Department of Psychiatry, UPMC Center for Integrative Medicine, Center for Research
5
on Health Care Data Center, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
Introduction: Studies on human pain genetics revealed that common polymorphisms in certain
genes (i.e., COMT, GCH1) affect pain perception and neural processing in multiple human cohorts,
yet no prior study has been performed in patients following TKA. Here we aimed to determine whether
genetic variations of COMT gene are associated with acute post-operative pain in TKA patients.
Material and methods: Caucasian patients from a major medical center (Shadyside hospital of
UMPS) were recruited prospectively prior to TKA surgery and followed through their hospital stay.
Clinical, demographic as well as baseline pain data was collected before surgery. Post-operative pain
in the affected knee at movement was assessed three times using numerical pain score (0-no pain,
10-highest pain) at day 1, 2 and 3, respectively. Five COMT single nucleotide polymorphisms (SNPs)
rs2097603, rs6269, rs4633, rs4818, and rs4680 were genotyped using TaqMan technology (Applied
1
Biosystems, CA). Regression analyses using PLINK software was used to model main effect of SNP
or haplotype on pain outcome after adjustment for covariates. A p-value of less than 0.05 was
considered to be statistically significant.
Results: A total of 149 patients (63 male, age mean 63.5 ±9.2) were genotyped. All the SNPs are in
Hardy-Weinberg equilibrium. We identified significant associations between pain at day 1 in femaleonly patients with rs6269 (p = 0.023) and rs4818 (p = 0.020), and trend of associations with rs4633 (p
= 0.077) and rs4680 (p = 0.077). Females with at least one copy of minor allele of the SNPs had
higher acute pain than those who do not. Haplotype analysis showed that the low pain sensitivity
2
(LPS) haplotype 'GCGG' was significantly associated (p = 0.05829) with pain score at day 1. No
association was identified in males.
Discussion: We identified that LPS haplotype previously reported as associated with less sensitivity
to painful stimulation and less chronic pain in females with temporomandibular joint disorder (TMD)2,
was associated with more acute post-operative pain (day 1) in TKA female patients. We therefore
confirmed sex-specific effects of COMT and revealed an interesting modality-specific effect since
COMT seems to contribute oppositely to acute and chronic pain. These findings, upon further
confirmation, can help clinicians in prediction and management of postoperative acute pain in TKA
patients.
Funding disclosure: The study was supported by NIH/NIDCR (0408-CT2048) to PI Dr. Jacques
Chelly.
Personal conflicts of interest disclosure: The authors declare that they have no conflicts of
interest.
References:
1. Purcell S, Neale B, Todd-Brown K, et al. PLINK: A Tool Set for Whole-Genome Association and
Population-Based Linkage Analyses. The American Journal of Human Genetics. 2007;81(3):559-575.
2. Diatchenko L, Slade GD, Nackley AG, et al. Genetic basis for individual variations in pain
perception and the development of a chronic pain condition. Hum. Mol. Genet. January 1, 2005
2005;14(1):135-143.
A90
IMPACT OF COMBINED SPINAL EPIDURAL (CSE) ON PERIOPERATIVE COURSE FOR TOTAL
HIP ARTHROPLASTY
J. Eiler, K. Schroeder, M. Donnelly, B. Anderson, A. Dickman, A. Dickman
University of Wisconsin Hospital and Clinics, Madison, WI, USA
Introduction: Total hip arthroplasty (THA) is a common orthopedic operation to improve mobility and
quality of life. In a continual effort to improve perioperative outcomes and patient experience, regional
anesthesia is a growing area requiring a delicate balance between pain control and rehabilitation
functionality. General anesthesia offers reliable surgical conditions, but with increased risk of nausea
and no perioperative regional pain control. Spinal anesthesia avoids the complications of general
anesthesia and offers a dense, predictable surgical block but little pain control postoperatively.
Lumbar epidural anesthesia offers the option for continued post-operative pain control, although
utilization may be limited by early ambulation goals, potent anticoagulant administration, and
unilateral blocks. At our institution, we utilize Combined Spinal-Epidural (CSE) anesthesia to
maximize the benefit of the two neuraxial techniques. Given the variability of patient management by
our orthopedic service, a portion of patients have their epidural utilized overnight (typically 0.15%
ropivacaine with 10 mcg/ml hydromorphone at a rate of 6 ml/hr) stopped at 0600 on POD#1 and the
remainder have it removed immediately following surgery. A Cochrane review by Choi et al in 2003
demonstrated no significant advantage to regional anesthesia beyond the early 4-6 hour mark in total
joint patients for pain control. This review attempted to determine the effect of our postoperative
analgesia infusion on outcomes following THA.
Materials and methods: Following IRB approval, a retrospective chart review analysis of prospective
data collection was completed at an academic university hospital. Participants included 320 patients
undergoing elective THA (111 CSE with epidural overnight, 85 CSE with epidural removed in OR)
from 3/11/2011 to 3/28/2012. Baseline patient characteristics and outcome variables were analyzed
including pain, opioid administration, opioid related side effects, rehabilitation outcomes, etc. To
standardize opioid administration, all opioids administered were converted into intravenous morphine
equivalents. A chi-squared test was used to analyze categorical variables while a Mann-Whitney test
was used for continuous variables.
Results: Baseline patient characteristics including age, gender and BMI were similar between groups.
CSE with postoperative infusion of local anesthetic and opioid resulted in significant decreases in
PACU, POD#0, and POD#1 peak and mean pain. CSE with postoperative epidural infusion also
resulted in significant decreases in PACU, POD#0, POD#1, and total opioid administration.
Postoperative nausea, rehabilitation goals and total hospital time were not impacted by postoperative
analgesic technique.
Discussion: The goal of this study was to analyze perioperative outcomes and patient experience for
patients undergoing THA. Our results demonstrate a significant benefit with postoperative epidural
infusions compared to intraoperative neuraxial blockade alone for pain control. There are other
mechanisms for postoperative pain control (i.e. lumbar plexus block) that may also be beneficial to
patients undergoing THA. Further study may be helpful to further define which postoperative
analgesic regimen is superior in patients undergoing THA.
References: Choi PT et al. Epidural analgesia for pain relief following hip or knee replacement.
Cochrane Database Review. 2003; 3.
Funding/personal conflicts of interest disclosure: Nothing to disclose.
A91
PATIENT ORIENTED OUTCOMES AFTER REGIONAL ANESTHESIA FOR ORTHOPEDIC
TRAUMA: A PROSPECTIVE COHORT STUDY
N.M. Elkassabany, L. Fan Cai, L. Pieczynski, J. Gaertner, S. Mehta, J. Ahn, J. Liu
1
2
3
University of Pennsylvania, Anesthesiology and Critical Care, Orthopedic Surgery, University of
Pennsylvania, Philadelphia, PA, USA
The need to measure, compare, and improve the quality of postoperative pain management is
increasingly sought by health care consumers, payers, and professionals. The Revised American
Pain Society Patient Outcome Questionnaire (APS-POQ-R) (figure 1) for quality improvement of pain
management in hospitalized adults has been published by the American Pain Society (APS) in 2010
1
to address this need . The questionnaire assesses the quality of postoperative pain management in
five domains; pain severity and sleep interference, interference with activity, severity of adverse
effects, affective subscale, and patient perception and satisfaction with their care.
The impact of regional anesthesia and analgesia on the patients' surgical experience as a whole and
2
their satisfaction with their care is better categorized as patient oriented outcomes . Certain
instruments are especially designed to measure quality of recovery, quality of life, and patient
satisfaction. The importance of these outcomes is increased with the implementation of the pay per
performance system. A second aim of this study is to measure the quality of recovery in the first 24,
3
and 48 hours after surgery suing the Quality of Recovery-9 (QOR-9) .
Material and methods: Patients admitted to the orthopedic trauma service at the hospital of the
University of Pennsylvania with a single extremity fracture. Patients with multiple traumas are
excluded.
Sample size: 100 patients will be enrolled in this study. Patients will be classified into one of two
groups, Regional Anesthesia (RA) group and Systemic Narcotic (SN) group, based on whether
regional anesthesia or analgesia has been used as part of their postoperative pain management
protocol.
Outcome end points: 1- APS-POQ-R in the first twenty four hours after surgery.
2- QOR-9 questionnaire at 24 and 48 hours
Results: We are presenting the preliminary results for the first twenty patients enrolled in this study.
The quality of pain management was better in the regional anesthesia group when compared with the
systemic opioid group. Regional anesthesia scored significantly better in four of the five subscales
assessed by the APS-POQ-R. Patients who had regional anesthesia had better pain control (p=0.02)
and less interference with sleep (p=0.03) and less adverse effects (p=0.07). Patients in the regional
anesthesia group also scored better in the affective subscale (p=0.001) domain and in their
satisfaction with pain management (p=0.08). There was no significant difference between the two
groups in terms of interference with activity (p=0.13).
Patients in the RA group scored better on the qor-9 at 24 hours. Average score was 13(12-15.5)
versus 11.5 (11-13) for the systemic opioid group. However, this difference was not statistically
significant (p=0.13). The QOR score at 48 hours was also similar between the two groups.
Discussion: Patient centered outcomes, are often overlooked in the regional anesthesia literature.
These outcomes should probably get more attention in future research studies.
Figure (1): The APS-POQ-R
[Figure 1, Page 1]
[Figure 1, Page 2]
References:
1- Gordon DB, et al. J Pain 2010;11(11):1172-86.
2- Wu CL, Fleisher LA. Anesth Analg 2000;91(5):1232-42.
3- Myles PS, et al 2000;28(3):276-80.
A92
THE PLACE AND ROLE OF TAP-BLOCK IN SPINE SURGERY
1
2
A. Ezhevskaya , A. Ovechkin , Z. Prusakova
1
1
Anesthesiology and Reanimation, Research Institute of Traumatology and Orthopedics, Nizhny
2
Novgorod, Anesthesiology and Reanimatology, I.M. Sechenov First Moscow State Medical
University, Moscow, Russia
Introduction: Transverse abdominal plane (TAP) block is a new approach to the bilateral blockade of
the afferent nerves of the abdominal wall through the lumbar triangle of Petit. In 2008 the technique
was offered to perform of hypochondrium oblique block of the TAP using ultrasound [1, 2]. We
evaluated its analgesic efficacy in patients during the first 24 hours perioperative period of
anterior/anterolateral retroperitoneal lumbar surgery in a randomized, controlled, clinical trial.
Material and methods: The study included 60 patients (women - 22 men - 18, age - 19-45 years,
ASA I-II). The following spine surgeries were performed: anterior or anterolateral retroperitoneal
approaches for spinal fusion L4-5 (12 of them - graft from the iliac bone, 38 - mesh, 10 - vertebral
body prosthesis). All patients were randomly divided into two groups: Group T (n=30) had TAP-block
and endotracheal anesthesia with sevoflurane and fentanil during surgery and Group G (n=30) had
general anesthesia with sevoflurane and fentanil and then systemic administration of opioids after
surgery. After induction of anesthesia and tracheal intubation patients in Group T were underwent
unilateral TAP-block 0.5% solution of 25 ml of ropivacaine after aspirate under ultrasound control
(SonoScape, China) on the mid-axillary line, between the iliac crest and the costal margin. Before
incision, patients in Group T received fentanyl 1 mcg/kg and then were entered it when necessary. At
the end of the surgery after the closure of the wound the catheter was placed into the TAP under
ultrasound and 5 ml of 0.5% ropivacaine solution was injected. After surgery patients in Group T were
administered boluses of 20 ml of ropivacaine 0.2% solution, 2 times a day for 3 days. After surgery
patients in both groups were administered ketorolac IM, 2 times a day for 3 days. Demographics, pain
at rest and in motion, nausea and vomiting were assessed during the first 24 hours after surgery.
Results: Patients with TAP-block needed for additional administration of narcotic analgesic occurred
for longer times. 14 patients in Group T (47%) did not need for opioids. In the Group T there was
significantly less pain at rest and in motion, and higher patient satisfaction. In comparison with Group
G, cases of nausea and vomiting were significantly less in patients of Group T. There was no pain in
12 patients in Group T (40%) during the first 24 hours.
Discussion: We conclude that using the TAP-block with ropivacaine as a component of anesthesia in
anterior/anterolateral retroperitoneal lumbar surgery provides better analgesia reduces the intensity of
pain after surgery, the need for opioids, improves postoperative patient comfort, and patient
satisfaction. The TAP-block is and effective regional component combined general anesthesia. It is
easily and safely to perform under ultrasound control.
References:
1. Hebbard P, Fujiwara Y, Shibata Y, Royse C. Ultrasound-guided transversus abdominis plane (TAP)
block. Anaesthesia and Intensive Care 2007;35:616-617.
2. Laffey J, McDonnell J. Subcostal Transversus Abdominis Plane Block Under Ultrasound Guidance.
Anesthesia and Analgesia 2008;106:675.
Funding: Health Ministry, Russia
Personal conflicts of interest disclosure: Nothing to disclose.
A93
EFFECT OF TWO-LEVEL THORACIC EPIDURAL ANESTHESIA ON HAEMODYNAMICS AND
HEMOSTASIS DURING DORSALIS CORRECTION OF SCOLIOSIS
1
A. Ezhevskaya , A. Ovechkin
2
1
Anesthesiology and Reanimation, Research Institute of Traumatology and Orthopedics, Nizhny
2
Novgorod, Anesthesiology and Reanimatology, I.M. Sechenov First Moscow State Medical
UniversityM, Moscow, Russia
Introduction: Anesthetic management of corrective operations is among the most sophisticated and
insufficiently solved problems of modern major spine surgery. Search for solutions of the problems,
ways and means of implementing anesthesiological protection remain relevant [1, 2]. We assessed
the effects of epidural anesthesia on systemic haemodynamics, the hydration state of the lungs and
the haemostatic system during surgical corrections of scoliosis.
Material and methods: The study included 135 patients, aged from 12 to 25 years with spinal
deformities of grade III-IV. All patients were randomly divided into 2 groups. Two-level (Th4-5 and
Th10-11) thoracic epidural anesthesia (EA) with 0.75% ropivacaine (15-25 ml) and 200 mcg of
fentanil and general endotracheal anesthesia with sevoflurane (0.8-1.5% vol.) were used in the Group
E (n = 70) and only general anesthesia with sevoflurane and fentanil was used in the Group G (n =
65) during the surgery. After the surgery in the Group E analgesia was performed by prolonged EA by
setting at the end of surgery two epidural catheters with ropivacaine, fentanil and epinephrine using
infusion pump. Patients in the Group G had systemic administration of opioids by controlled
analgesia. Blood loss and coagulation parameters were assessed during the surgery. Systemic
hemodynamic parameters were measured using non-invasive monitoring of hemodynamic
parameters on the basis of impedance cardiography (ICG) using a «NICCOMO» (Germany).
Results: The study revealed a statistically significant reduction in intraoperative blood loss on 50% in
the Group E (568 ml, p=0.0013). Noninvasive hemodynamic monitoring showed that EA does not lead
to life-threatening disorders in myocardial contractility, cardiac output, systemic vascular resistance
and critical increase of the content of extravascular lung water. However surgical interventions were
accompanied by significant changes in the parameters of hemostasis and characterized
hypercoagulated changes in both groups, but more expressed in the Group G.
Discussion: We suppose that the main reason for a significant decreasing of intraoperative blood
loss due to effects of sympathetic blockade of epidural analgesia. Evoked controlled hypotension, low
blood pressure in the epidural veins and intraosseous pressure are main factors of affecting blood
loss. The results show that the reaction of the haemostatic system in the operation is the
simultaneous amplification of coagulation and fibrinolysis. Most likely, the role of the thoracic EA is to
control the activation of hemostasis / fibrinolysis.
Thus, stage epidural analgesia in the surgical correction of scoliosis can be successfully used both
during and after surgery, providing a reliable multi-level nociception, less blood loss, and modulation
of the endocrine stress response.
References:
1. Blumenthal S, Min K, Nadig M, Borgeat A. Double epidural catheter with ropivacaine versus
intravenous morphine: a comparison for postoperative analgesia after scoliosis correction surgery //
Anesthesiology. - 2005; 102. - P.175-180.
2. Wenk M, Ertmer C, Weber TP, et al. 2010 Feasibility and Efficacy of Preoperative Epidural
Catheter Placement for Anterior Scoliosis Surgery // Anesthesiology. - 2010. - Vol 113. - P. 353-9.
Funding: Health Ministry, Russia
Personal conflicts of interest disclosure: Nothing to disclose.
A94
REGIONAL ANESTHETIC INJECTION PRESSURES BY SKILLED ASSISTANTS IN A
SIMULATED ULTRASOUND GUIDED TECHNIQUE
E. Fawzy, J. Carter, R. Heij, A. Ali, M. Liu, J. Gibson, P. Young
Anaesthesia, Queen ELizabeth Hospital, King's Lyn, King's Lynn, UK
Introduction: Injection during regional anesthesia risks permanent nerve injury when pressures in
1
excess of 11 PSI are applied . Previous studies have demonstrated that perception of appropriate,
2
safe injection pressure varies widely . The performance of ultrasound (US) guided regional
anesthesia requires a two-handed approach and hence the syringe is held, and injection performed,
by a skilled assistant. We tested operating department practitioners (who routinely perform this
injection in our institution) during a simulated ultrasound guided regional anesthetic recording the
pressure of injection.
Materials and methods: Requirement for formal ethical approval was waived by our institutional
research governance committee. Written consent was obtained. Whilst an investigator was performing
an US guided block on a chicken leg or phantom, each participant (n=20) was asked to assess US
visualization of 2mL aliquots of local anesthetic. Injection was performed by each participant using a
20mL syringe (Terumo, Egham, UK) as per normal institutional practice. Each was asked to inject and
aspirate exactly as they would do clinically and specifically told not to inject if they did not feel happy
to. Unknown to the participants, prior to the commencement of each 2mL aliquot injection, a second
investigator applied a constant known pressure to the injection system using a calibrated constant
pressure generator (Fluke Biomedical, Everett, WA) at 5, 10, 15, 20, 25 and 30 PSI in random order.
Participants indicated when they were unhappy to inject and the needle was moved. The next
pressure in the random sequence was then surreptitiously applied. If injection was performed then the
injection pressure was changed during the aspiration period of every 2mL aliquot.
Results: Fourteen of the 20 participants (70%) injected at 15 PSI or above (see Figure 1).
Four participants (20%) injected at 20 PSI, two (10%) at 25 PSI and two (10%) at 30 PSI.
Interestingly, all participants who injected at 20 PSI and above were male. Furthermore, three of the
six participants who were not willing to inject at 15 PSI or higher had more than 20 years experience.
[Figure 1]
Discussion: Avoiding intra-neural injection is a fundamental requirement during the performance of
any regional anesthetic technique. An anesthesiologist using a two-handed US guided approach
relies on a skilled assistant to inject the local anesthetic solution. Our results confirm that the majority
of skilled participants would inject at higher pressures than considered to be safe.
References:
1. Hadzic et al. Combination of Intraneural Injection and High injection Pressure Leads to Fascicular
Injury and Neurological Deficit in Dogs Reg Anes Pain Med 2004;29:417—423
2. Claudio et al. Injection Pressures by Anesthesiologists During Simulated Peripheral Nerve Block
Reg Anes Pain Med 2004;29:201-205
A95
COMBINED FEMORAL NERVE BLOCK AND MULTIMODAL ANALGESIA REDUCES EARLY
POSTOPERATIVE PAIN SCORES AT REST AND DURING PHYSICAL THERAPY IN PATIENTS
UNDERGOING TOTAL KNEE ARTHROPLASTY
L.O. Mark, R. Bengali, E.A. Jacob, A.A. Freiberg, R. Dorman, V.J. Hansen, R. Peloquin, P.
Stefanovich, K.H. Fleischmann
1
2
Department of Anesthesia, Critical Care, and Pain Medicine, Department of Orthopedic Surgery,
4
Department of Physical Therapy Services, Harris Orthopedic Lab, Massachusetts General Hospital,
Boston, MA, USA
3
Introduction: Femoral nerve blocks and multimodal analgesia are known to improve pain control at
1
rest and decrease hospital length of stay following total knee arthroplasty . However, it is less clear
whether these interventions affect early ambulation pain scores in the postoperative period. We
investigate early postoperative (POD 0 and 1) pain score reduction after total knee arthroplasty at rest
and during physical therapy ambulation in patients who received multimodal oral analgesics, femoral
nerve block, and intra-operative multimodal peri-articular injection.
Materials and methods: Sixty-four patients who underwent total knee arthroplasty by a single
orthopedic surgeon at Massachusetts General Hospital in 2010 and 2012 were randomly selected
and retrospectively enrolled in the study. Patients in the test group received preoperative multimodal
oral analgesics (celecoxib 400 mg, oxycodone continuous release 10-20 mg, and acetaminophen 975
mg), femoral nerve block (20 mL of 0.2% ropivacaine with 1:400,000 epinephrine), and intra-operative
multimodal analgesia injection (ketorolac 30 mg, epinephrine 0.5 mg, clonidine 0.08 mg, and
ropivacaine 300 mg in normal saline with a final volume of 150 ml) (n=33).
Patients in the control group did not receive these interventions (n=31). The two groups were queried
for postoperative pain scores at rest, and 59 of the 64 patients were further studied for pain scores
during physical therapy with ambulation. All patients received general or spinal anesthesia and
standard postoperative pain medications as needed.
Pain scores were reported using a standard zero through ten scoring system by physical therapy.
Statistical calculations were performed with two-tailed, unpaired t-tests with significance set at p<
0.05.
Results: Mean early postoperative pain scores (POD 0 and 1) were significantly reduced in the test
group compared to the control group at rest (2.6 vs. 3.7, p=0.03) and during active physical therapy
(3.6 vs. 5.4, p=0.002) (Figure 1). A trend towards improved pain scores on POD 0 compared to POD
1 was noted, though the sample size is small. The test and control groups had equal distributions of
spinal and general anesthetics.
[Figure 1]
Discussion: In this retrospective study, femoral nerve block plus multimodal analgesia significantly
reduced early postoperative pain scores at rest and during physical therapy with ambulation. Stronger
significance was noted for early ambulation. Our data suggests that this combination mode of therapy
may also reduce pain scores immediately postoperatively (POD 0), enabling very early mobilization of
patients undergoing total knee arthroplasty. This may have significant clinical benefit as it may lower
2
the incidence of deep venous thrombosis . Further studies with larger sample sizes are needed to
confirm these observations.
References:
1. Tripuraneni KR, Woolson ST, Giori NJ. Local infiltration analgesia in TKA patients reduces length of
stay and postoperative pain scores. Orthopedics. 2011 Mar 1;34(3):173.
2. Nakao S, Takata S, Uemura H, Nakano S, Egawa H, Kawasaki Y, Kashihara M, Yasui N. Early
ambulation after total knee arthroplasty prevents patients with osteoarthritis and rheumatoid arthritis
from developing postoperative higher levels of D-dimer. J Med Invest. 2010 Feb;57(1-2):146-51.
COIs and Funding: none
A96
INTRODUCING ULTRASOUND-GUIDED PARAVERTEBRAL BLOCKS INTO CLINICAL
PRACTICE FOR TOTAL MASTECTOMY: A RETROSPECTIVE REVIEW OF OUR FIRST YEAR OF
EXPERIENCE
J.S. Green, R. Theron, N. Amyotte, S.M. Hamilton, M. van Wijngaarden-Stephens, B.C.H. Tsui,
Edmonton Academy of Regional Anesthesia
1
2
Anesthesiology and Pain Medicine, Surgery, University of Alberta, Edmonton, AB, Canada
Introduction: Clinical evidence suggests a significant improvement in pain control and post-operative
nausea and vomiting when using paravertebral blocks compared to oral and intravenous analgesia
1;2
alone.
Ultrasound-guided paravertebral blocks were introduced into clinical practice at the
University of Alberta Hospital in November 2010 for patients undergoing total mastectomy. This
retrospective review compares a time-matched cohort of patients receiving paravertebral blocks to a
cohort that did not. We hypothesized that patients undergoing a paravertebral block would experience
less pain and nausea than patients not receiving the block.
Material and methods: We performed a retrospective review of 100 consecutive total mastectomy
cases from November 2010. Following institutional ethical approval, patients who underwent total
mastectomy were identified via the surgeon's office. A retrospective medical chart review was then
performed to identify opiate use, pain scores, incidence of nausea, vomiting, anti-emetic use, and
complications relating to placement of paravertebral block. Outcomes of patients who received
paravertebral blocks were then compared to those that did not. Groups were not stratified by breast
cancer stage.
Results: A total of 102 patients were included in the review. Of these, 34 received a paravertebral
block and 68 did not. No incidence of pneumothorax or significant bradycardia/hypotension relating to
paravertebral block was found. Seven patients (20%) who received a paravertebral block reported a
pain score >5 in the post-operative recovery room (PARR). We also observed a significant decrease
in both the total intra- and post-operative IV opiate use and incidence of nausea and vomiting in the
paravertebral group (Table).
[Table]
Discussion: There is a learning curve with any new procedure, and failures and complications are
expected to occur more frequently during this learning period. A total of seven members of the acute
pain service including fellows were learning the technique during this time. It was therefore reassuring
that no complications were found, and we showed a significant reduction in opiate use and nausea
incidence during this introductory period. Although we were disappointed that 20% of patients
reported pain scores greater than five in PARR, the causes of pain are multifactorial and include pain
from the site of axillary node dissection, which is not covered by the paravertebral block. We expect to
improve these results by standardizing simple oral analgesia, routine anti-emetic use, and anesthetic
regime. Optimization of paravertebral local anesthetic concentration, volume, technique, and possible
catheter placement may also improve outcome.
References:
1. Schnabel A et al., Br. J. Anaesth. 2010; 105:842-52.
2. Tahiri Y, et al. J. Plast. Reconstr. Aesthet. Surg. 2011; 64:1261-9.
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society.
Personal conflicts of interest: Nothing to disclose.
Table. Opiate use and incidence of nausea, vomiting, and/or antiemetic use.
A97
CASELOAD VARIABILITY OF AN ACUTE PAIN SERVICE AT A LEVEL ONE TRAUMA CENTER:
IMPLICATIONS FOR MANPOWER MANAGEMENT
R. Guffey, E. Conrad, F.J. Auerbach, J.E. Chelly
Anesthesia, UPMC - Posner Pain Center, Pittsburgh, PA, USA
Introduction: Acute pain services (APS) are often considered a cost center, and therefore resources
required to cover the needs of the service are often difficult to secure. This is as much on the side of
the department as the hospital. Characteristic to an APS in a trauma center are frequent unscheduled
consults. The goal of this study was to assess the trauma related consult variability and determine
how it impacts manpower coverage.
Methods: The number of unscheduled trauma consults was reviewed over a period of 12 months.
Since August was identified as the month with the greatest number of unscheduled consults, this
month was chosen for further study. Next, APS consults between August 1-31 were analyzed using
our IRB approved database. Only data from weekdays were considered (Monday through Friday).
After determination that our data were normally distributed, data are presented as mean ± SD.
Results: The APS was consulted on 395 patients over the 23 days of the study period. Of those
consults 254 (63%) were scheduled. Twenty two of the scheduled consults (9% of scheduled) were
cancelled the morning of surgery. The distribution of consults varies daily (Figure 1). A total of the 358
patients seen by APS and 269 (75%) were blocked. In 90% of cases the block was performed
preoperatively and 60% of consults were for inpatients. Most patients managed medically were for
minor rib fractures, large burns or acute on chronic pain who did not consent for blocks. Our
scheduled vs. actual number of patients to block as first start OR cases (7:30 AM) varied significantly
according to the days of the week. Sixty one percent of nerve blocks placed on inpatients were
catheters, while only 16% of outpatient nerve blocks were catheters. Staffing was not associated with
requirement for postoperative nerve blockade.
Discussion: Our results show that case variability did not significantly impact our ability to block
patients preoperatively during a heavy trauma month. This was due to the model used to schedule
staff for our APS. It is based on a flexible schedule such that staffing to each site is modulated
according to the number of blocks scheduled the day before at each site. Although a specific regional
attending is assigned to the APS on a daily basis (2 on Monday and Friday), at least one additional
attending is scheduled to work in the OR with the ability to help supervise blocks if necessary.
Inadequate staffing was not associated with the need for postoperative nerve blockade. The majority
of cases of postoperative nerve blockade were due to the inability for patients to come to the
preoperative area with adequate time to be blocked without delaying the surgery.
[Figure 1]
Figure 1 Average number of patients seen by the AIPPS. The number of patients scheduled split by
day of the week is significant by ANOVA (p < 0.005). * Standard deviation
References: None
Funding: Departmental
Conflicts of interest: Nothing to disclose
A98
IMPROVING NEEDLE VISUALIZATION BY NOVICE RESIDENTS DURING AN IN-PLANE
ULTRASOUND NERVE BLOCK SIMULATION USING THE CIVCO INFINITI™ NEEDLE GUIDE
R. Gupta, J. Lane, B. Allen, Y. Shi, J. Schildcrout
1
2
3
Anesthesiology, Biostatistics, Biostatistics and Anesthesiology, Vanderbilt University, Nashville, TN,
USA
Background and objectives: Ultrasound-guided Regional Anaesthesia with in-plane needle
approaches can be challenging due to difficult needle visualization. We hypothesized that the CIVCO
TM
Infiniti needle guide can help reduce the time it takes novice regional anesthesiologists to perform a
simulated ultrasound-guided nerve targeting procedure and enhance the visualization of the needle.
Methods: Sixteen volunteers were randomized to repeat a single nerve targeting simulation task 4
times with and 4 times without the needle guide in a crossover study design. Endpoints were time to
complete the nerve targeting, needle visualization, number of passes, and needle approximation to
the target.
Results: The needle guide reduced median time to complete the task by 27% (95% confidence
interval: 4% - 44%) and increased the odds of effective needle visualization by 355% (95%
confidence interval: 171% - 737%). A learning benefit was also noted with multiple attempts
regardless of whether the needle guide was used or not.
TM
Conclusions: The CIVCO Infiniti needle guide can help reduce the time needed to complete a
simulated nerve targeting procedure and enhance needle visualization for the novice sonographer in
a phantom gel simulation. There was no significant reduction in the number of needle passes or in
improvement of target approximation noted.
A99
PRE-INCISIONAL PARAVERTEBRAL AND PARASPINOUS BLOCK FOR MASTECTOMY AND
RECONSTRUCTION
M. Guzman
Community Surgery Center East, Indianapolis, IN, USA
Introduction: Pre-incisional thoracic paravertebral blocks(PTPVB) are associated with reduced pain
scores in women undergoing mastectomy and reconstruction. Multiple thoracic levels may need to be
blocked to obtain adequate analgesia. These observations prompted the hypothesis that placement of
a multi-orificed soaker catheter lateral to T 5/6 to C7 could provide additional pain relief to a single
PTPVB.
Method: 61 women were scheduled for unilateral or bilateral modified radical mastectomy with
reconstruction. All patients received a single, ultrasound guided PTPVB, transverse approach, at
T4/5, ropivacaine 0.5% 15 ml/side. A 6 inch needle/sheath(Figure 1) was placed 1-2 cm lateral to the
spinous process, directly over the top of the external intercostal muscles from T5/6 to C7. The 6 inch
needle was removed, leaving a peel away sheath in place. A 5 inch multi-orificed catheter was placed
through the sheath and the sheath was then removed. An elastomeric infusion device containing
ropivacaine 0,2% was connected at 7 ml/side. PACU patients were placed on a multimodal pathway
consisting of intravenous acetaminophen,NSAIDS, and oxycodone prn. Hydromorphone .5mg was
given prn. Paraspinous catheters were dosed with ropivacaine 0.5% 15ml/side on arrival to PACU
and again the following morning. Patients were discharged with their elastomeric pump at 4 ml/hour
for an additional 36 hours.
Results: 96 PTPVB were performed for mastectomy and reconstruction. Remarkably, 10 of the 60
patients reported zero pain and received no opiates. 50 patients immediate PACU scores were 37/10, with all responding to IV hydromorphone, usually 1 mg or less. Most patients had pain scores of
2-4/10 within 3 hours of starting the multimodal regimen. 50 patients had pain scores of 1-3/10 at 7
am postoperative day one, and at this time all paraspinous catheters were dosed with ropivacaine
0.5% 15 ml/side. All women reported additional pain relief and better range of motion after the am
bolus. Pain scores on discharge were 0-2/10. No patients showed signs of an epidural block or had
rebound pain after removal of the paraspinous catheter.
Discussion: PTPVB has been shown to decrease acute pain scores and also reduce chronic pain in
mastectomy patients at 1,6, and 12 months. For this reason our patients received a single PTPVB
with each paraspinous catheter. It is common to perform more than one PTPVB to provide greater
coverage. Bilateral surgery can easily require 4-6 individual blocks. Extending the duration of a
PTPVB requires placing a continuous catheter and increases the complexity of this block. A
multiorificed catheter was chosen that would extend from T 5/6 to C7. Ultrasound Figure 2 shows a
transverse view of the paraspinous catheter soaking the intercostal muscle and explains the
phenomenal effect we have seen using this multilevel continuous intercostal nerve block. Our patients
have shown extremely low pain scores and great range of motion on discharge. Presented is a
relatively simple technique for continuous intercostal nerve blocks.
[Figure 1]
[Figure 2]
A100
RIVAROXABAN OR CONVENTIONAL THROMBOPROPHYLAXIS IN ROUTINE CLINICAL CARE SUBGROUP ANALYSIS OF THE XAMOS STUDY BY TYPES OF ANESTHESIA USED
1
2
2
3
4
S. Haas , G. Holberg , R. Kreutz , M.R.L. Lassen , L. Mantovani , A.G. Turpie
1
5
2
3
Technical University Munich, Munich, Global Medical Affairs, Bayer HealthCare AG, Institut für
4
Klinische Pharmakologie und Toxikologie, Charité-Universitätsmedizin, Berlin, Germany, Glostrup
5
Hospital, University of Copenhagen, Copenhagen, Denmark, CIRFF, Center of Pharmacoeconomics,
6
Federico II University of Naples, Naples, Italy, Department of Medicine, Hamilton Health Services,
Hamilton, ON, Canada
1
Introduction: Data from the non-interventional phase IV XAMOS study reflected the benefit-risk
profile of rivaroxaban seen in the phase III RECORD studies for the prevention of venous
2-5
thromboembolism after elective total hip or knee replacement surgery. The aim of this subanalysis
was to describe the pattern of anesthesia used and the potential influence of anesthesia type on
outcomes in the XAMOS study.
Material and methods: The types of anesthesia and adverse events, including symptomatic
thromboembolic and bleeding events, were reported by the investigators. In this analysis, subgroups
were generated according to the type of anesthesia and the type of surgery (i.e. hip or knee
replacement surgery). Types of anesthesia were categorized as: general, neuraxial (including
combinations of spinal/epidural and local anesthesia), peripheral, combinations of general and other
anesthesia, and other combinations (Table).
Results: Of the 17,701 patients enrolled, 8778 received rivaroxaban and 8635 received standard of
care (SOC) pharmacological thromboprophylaxis. In the SOC group, 81.7% of patients received low
molecular weight heparin (LMWH) and 7.9% received fondaparinux. The types of anesthesia used
were similar between the rivaroxaban and SOC groups. Neuraxial anesthesia was used more than
any other form of anesthesia (59.1-61.3%) in patients receiving rivaroxaban, SOC, or LMWH (Table).
General anesthesia was used more often in patients undergoing hip surgery (38.8-43.2%) compared
with those undergoing knee surgery (29.4-29.5%; Table). There was a numerically lower incidence of
symptomatic thromboembolic events in patients who had neuraxial anesthesia compared with those
who received general anesthesia in both treatment groups. Further clinical outcomes according to
different types of anesthesia and surgery will be presented.
Discussion: This subanalysis showed that, in routine clinical care in unselected patients undergoing
major hip or knee surgery, neuraxial anesthesia was used more often than other types of anesthesia,
which is consistent with the pattern observed in the RECORD studies. General anesthesia was used
more frequently in hip surgery than in knee surgery, although no difference was observed in the
anesthesia used between the rivaroxaban and SOC groups.
References:
1. Turpie AGG et al. Br J Haematol 2012;157:9-10. Abstract 20.
2. Eriksson BI et al. N Engl J Med 2008;358:2765-2775.
3. Kakkar AK et al. Lancet 2008;372:31-39.
4. Lassen MR et al. N Engl J Med 2008;358:2776-2786.
5. Turpie AGG et al. Lancet 2009;373:1673-1680.
Funding source: This study was funded by Bayer HealthCare Pharmaceuticals.
Table. Types of anesthesia used in the XAMOS study
All surgery types
Hip surgery
Knee surgery
Combinati
Other
Gener Neuraxia Peripheral on of
Gener Neuraxia Gener Neuraxia
combinatio
al
l*
**
general
al
l*
al
l*
ns
and others
Rivaroxaba
36.9
n, %
59.1
0.6
3.1
0.1
43.2
54.4
29.5
64.7
SOC, %
36.3
59.8
0.7
2.9
0.1
41.8
56.0
29.5
64.7
LMWH, %
34.6
61.3
0.8
3.0
0.1
38.8
58.9
29.4
64.5
*Neuraxial includes: spinal; spinal and epidural with or without indwelling catheter; spinal and femoral
block; spinal and paravertebral block; spinal and LIA; epidural without and with indwelling catheter;
epidural without indwelling catheter and femoral block; epidural without indwelling catheter and
paravertebral block; epidural without indwelling catheter and LIA; epidural with indwelling catheter and
femoral block; epidural with indwelling catheter and paravertebral block; epidural with indwelling
catheter and LIA. **Peripheral includes: femoral block, paravertebral block, LIA, femoral block and
paravertebral block, femoral block and LIA, paravertebral block and LIA. LIA, local infiltration
anesthesia; LMWH, low molecular weight heparin; SOC, standard of care.
A101
CAN LOCAL ANESTHETIC SPREAD SEEN ON ULTRASOUND PREDICT ONSET, SUCCESS,
AND DURATION OF INTERSCALENE NERVE BLOCKS?
1
2
2
1
M.W. Harbell , J. Geerling , P.E. Hess , P. Aleshi
1
Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA,
Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, USA
2
Introduction: Recent studies suggest that a circumferential spread of local anesthetic (LA) around
the sciatic nerve leads to faster onset and improved sensory block [1]. Achieving this “donut sign” has
become a common goal in ultrasound-guided blocks. However, this has not been demonstrated for
interscalene nerve blocks (ISB) [2]. We hypothesized that spread of LA seen on ultrasound can
predict onset of motor blockade, block success, and block duration of ISB.
Methods: After obtaining IRB approval, 93 ASA I-III patients received ISB with 30 ml bupivacaine
0.375% with epinephrine 5mcg/ml prior to upper extremity surgery under general anesthesia. ISB was
performed with ultrasound, nerve stimulation or with a combination of the two depending on
anesthesiologist preference. Immediate pre- and post-block ultrasound images were obtained by the
same operator. The onset of sensory and motor blocks (loss of shoulder abduction), perioperative
analgesic use, success rate, and patient satisfaction were recorded.
Three visualization scores were used to analyze the appearance of LA spread on ultrasound
immediately post-block injection. These scores were based on the number of trunks visualized,
distortion of nerves, donut spread of LA, and tracking of LA along nerve in the loop image of the
nerve.
Results: 82 of the 93 patients enrolled in the study had complete pre- and post-block images. The
overall failure rate was 8.6%. None of the visualization scores developed correlated with onset of
motor blockade, block duration, or block success. 71% of the failed blocks appear to have a “donut
sign” spread of LA. Block failure was not statistically different between nerve stimulator and
ultrasound guided techniques (NS 7/65, 11% vs. US 1/24, 4%; p= 0.44). Block failure significantly
correlated with lack of motor block prior to surgery (2/8 (25%) vs. 69/82 (84%), p= 0.001). Block
failure was associated with lack of ulnar and median sensory block onset prior to surgery (Ulnar 2/8,
25% vs. 60/82 (73%), p= 0.01; median 4/8 (50%) vs. 73/82 (89%), p= 0.01), but not with lack of radial
sensory block onset prior to surgery.
Discussion: Post-injection spread of local anesthetic does not predict successful ISB, nor does it
correlate with onset or duration of anesthesia. Further, achieving a “donut sign” during ISB does not
guarantee a successful block. Lack of motor block was the strongest predictor for block failure. Lack
of ulnar and median sensory block, but not radial, was also predictive of block failure.
References:
1. Missair A, Weisman RS, Suarez MR, Yang R, Gebhard RE. A 3-Dimensional Ultrasound Study of
Local Anesthetic Spread During Lateral Popliteal Nerve Block. RAPM 2012, 37(6): 627-632.
2. Lang RS, Kentor ML, Vallejo M, Bigeleisen P, Wisniewski R, Orebaugh SL. The impact of local
anesthetic distribution on block onset in ultrasound-guided interscalene block. Acta Anaestheiol
Scand 2012, 56: 1146-1151.
Funding: Beth Israel Anesthesia Foundation
Personal conflicts of interest disclosure: Hess - consultation for Philips Ultrasound, Inc.
A102
SCANNING ELECTRON MICROSCOPIC ANALYSIS OF CUT EPIDURAL CATHETERS. A PILOT
STUDY
1
1
G. Holck , E.A. Goytizolo , L.C. Tsen
1
2
2
Department of Anesthesiology, Hospital for Special Surgery, New York, NY, Department of
Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Boston, MA, USA
Introduction: Anesthesiologists due to tip contamination during epidural catheter (EC) placement or
1
adapter disconnection , eventually, can cut the EC. This practice could generate microfragments from
the cut tip, which could migrate to the epidural space and lead to epidural granuloma. We
hypothesized that cutting the EC produce microfragments and the Scanning Electron Microscopy
(SEM) technique permits the identification of these microfragments at the edge of the cut catheter and
in the distilled water (DW) injected through the EC.
Material and methods: Three different types of EC from different manufactures (B. Braum Medical
®
Inc. Perifix , BD Medical Perisafe™, Arrow International Inc. FlexTip Plus®) were analyzed under
SEM. A standard SEM view of each catheter type was obtained before intervention to determine the
baseline pattern for each manufacturer. The ECs were divided in 2 groups with 5 ECs of each type
(n=15 per group); using a standardized cutting method the first group was cut with scissors (SC
group) and the second group cut with scalpel blade (BL group). After a SEM view of the cut tip was
acquired, 0.2 ml of DW was injected using a connector attached to the cut tip. Then, this tip was
reanalyzed and also the content washed out from the EC was analyzed to search for microfragments.
Results: In this observational study, as a preliminary result, the images obtained show presence of
microfragments at the cut EC tip in 100% of the samples analyzed. The fragments size widely varied
(12.5 - 116.25 µm). The scalpel group had less traumatic microscopic pattern and generated less
microfragments than the scissors group. After cutting the EC, attaching the connector and injecting
DW the EC tips reanalyzed showed no more loose fragments that had been washed out by the DW.
The analysis of the DW injected through the cut EC demonstrated presence of microfragments.
[BBraum catheter ]
[Arrow catheter ]
Discussion: A few case-reports in the literature associate epidural granuloma formation and prior
2,3
continuous epidural anesthesia . However, this association is not completely understood. Possible
4
4
causes could be trauma related to EC placement , contained infection , organized epidural
2
5
6
hematoma , drug-induced reaction and particles from surgical gloves . To our knowledge, fragments
from the EC have not been evaluated as potential cause for epidural granuloma following continuous
epidural anesthesia, especially if the EC has been cut. According to our findings, using SEM, it is
evident that cutting the EC generates microfragments at the cut tip. These fragments can be
dislocated into the epidural space when a liquid solution is injected through the cut EC and potentially
generate epidural granuloma.
References:
1. Anaesthesia 2000; 55: 192-3.
2. Anaesth Intensive Care. 2010;38:779-80.
3. Orthopedics 2009;32:293.
4. Am J Neuroradiol 2005; 26:991-995.
5. Neurosurgery 2002;50:78-86.
6. Rev Esp Anestesiol Reanim. 1999;46:60-6.
Funding disclosure: Support was provided solely from departmental sources.
Personal conflicts of interest disclosure: Nothing to disclose.
A103
ARTHROPLASTY CARE REDESIGN: IMPACT OF SPINAL DOSING ON POST ANESTHESIA
RECOVERY UNIT LENGTH OF STAY AFTER TOTAL HIP ARTHROPLASTY
A. Holman, E. Jacob, K. McCarty, M. Rozanski, R. Dorman, O. Evgenov, K. Fleischmann, A.
Freiberg, M. Gargarian, W. Levine, J. Lewis, V. Modest, P. Stefanovich, S. Vassallo, J. Wang, L.
Warren, L. Wollman-Kliman, J. Rathmell, R. Peloquin, MGH Arthroplasty Care Redesign Team
1
2
Department of Anesthesia, Critical Care, and Pain Medicine, Department of Physical Therapy
3
Services, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA
Introduction: In 2011, the Massachusetts General Hospital Arthroplasty Care Redesign Team was
charged with evaluating arthroplasty care with the aim of reducing cost while maintaining or improving
quality. A previously identified limitation to early ambulation and thus overall length of hospitalization
was extended length of stay in the PACU (PACU LOS), particularly among patients receiving spinal
1
anesthesia (SA) for Total Hip Arthroplasty (THA). This led to a systematic examination of THA SA
dosing and subsequent efforts to reduce those doses. In this study, we analyzed the influence of SA
Bupivacaine dose on PACU LOS after THA in comparison with use of general anesthesia (GA).
Materials and methods: Using our anesthesia perioperative electronic health record, we
retrospectively reviewed all adult patients who underwent THA at MGH from January 1, 2010 September 30, 2012. The primary endpoint was PACU LOS. All data are shown as mean ± standard
deviation and were analyzed using two-tailed t-tests with significance set at p < 0.05.
Results: PACU LOS for patients receiving high-dose and low-dose SA was 265±98 min and 230±88
min, respectively (Figure 1, Table 1).
[Figure 1 - PACU LOS as a Function of SA Dose]
Period 1-Period 2
Hips Low-dose (< 15mg)
Hips High-dose (≥ 15mg)
Average PACU LOS (min)
230
265
PACU LOS SD
88.0
98.2
Average Dose of 0.5%
Bupivicaine (mg)
12.2
18.1
[Tabe 1 - PACU LOS and SA Bupivicaine Dosing]
SA dosing decreased from 18.7±2 mg in Period 1 to 15.3±2 mg in Period 2 (Table 2, p < 0.001).
Average Dose of 0.5% Bupivicaine for Spinal Arthroplasties in Period 1 and Period 2
Average Dose in Period Average Dose in
1
Quarter 1 Period 2
Average Dose in
Quarter 2 Period 2
Average Dose in
Quarter 3 Period 2
18.7 ± 2 mg
16.4 ± 2 mg
15.3 ± 3 mg
16.2 ± 2 mg
[Table 2 - THA Average Dose for SA]
PACU LOS in those receiving SA decreased from 272±97 min during Period 1 to 242±94 min during
Period 2 (p < 0.001). PACU LOS also decreased in those receiving GA from 222±97 min during
Period 1 to 204±113 min during Period 2 (Figure 2, p = 0.03).
[Figure 2 - Average THA Surgical and Recovery Times]
For all patients undergoing THA, recovery time decreased from 249±100 min during Period 1 to
221±107 min during Period 2 (p < 0.001). The overall reduction in PACU LOS during Period 2 was
10,052 minutes of PACU recovery time.
Discussion: Extended PACU LOS delays physical therapy and early mobilization following THA. In
January 2012, MGH anesthesia practitioners were encouraged to reduce 0.5% Bupivacaine doses
used for THA. Examination of our anesthetic outcomes led to a significant reduction in SA doses and
an associated reduction in PACU LOS. Further study is needed to establish optimal SA dosing
assuring sufficient anesthesia duration while minimizing recovery time.
References:
1. McCarty et al., “Impact of General versus Spinal Anesthesia on Post-Anesthesia Care Unit
Recovery Time Following Total Hip and Knee” ASA Conference Abstract October 2012.
2. Macfarlane et al., “Does Regional Anesthesia Improve Outcome After Total Hip Arthroplasty?”
Br.J.Anaesth (2009); 103:335-45.
Funding: MGH Center for Quality and Safety Clinical Innovation Award
Nothing to disclose.
A104
LOW INCIDENCE IN DELAYS FOR FIRST CASE STARTS WITH THE IMPLEMENTATION OF A
DEDICATED BLOCK TEAM
B.-S. Hoter, M. Semenza, J.-L. Horn
1
2
Surgical Services, Anesthesiology and Perioperative Medicine, Oregon Health and Science
University, Portland, OR, USA
Introduction: With the current push to have all patients in their operating room (OR) in a timely
fashion for first case starts, regional anesthesia (RA) adds a potential delay. To minimize first case
delays associated with RA techniques we implemented a separate block team out of the OR that
performs all perioperative RA. In January 2012 our institution funded a specialized block nurse
dedicated to coordinating care with the regional anesthesia team. In April of that year the block team
started tracking factors responsible for OR delays. The goal of this study is find the incidence and
reasons for first case delays in patients being taken care of by the block team.
Methods: Our specialized block team consists of an attending anesthesiologist and a resident on a
RA rotation both otherwise unassigned in the OR, an anesthesia technician, and a block nurse. The
team has a dedicated space with ultrasound machines, block carts and procedure bays with full
monitoring capability. The block team briefs to plan the next day's RA with a focus on communication
with all parties involved. Potential block candidates are identified and placed on an expedited list to be
ready for the block team by 06:30. When a patient is included in the pathway, the end of the
procedure and the readiness for OR transportation is recorded. For any patient not ready by 07:25 for
07:30 in-room start time, the reason for the delay is identified and then verified with the responsible
party and validated by the preoperative charge nurse keeping track of case timing. Data from April to
July 2012 were collected and reasons for delays were recorded.
Results: The distribution of delays is illustrated in Fig. 1. During the 4-month period the block team
took care of 190 patients for first case starts. Twenty-eight patients (14.7%) arrived late to the OR.
The top three reasons were:
1) lack of surgical consent (9 patients, 4.7%);
2) difficulties with block placement (7 patients, 3.7%); and
3) late patient arrival (5 patients, 2.6%).
Among the 7 patients delayed because of the block, 6 were due to peripheral nerve blocks and 1 due
to epidural.
[Fig. 1]
Conclusions: Implementation of a program with a dedicated block team, early planning and constant
communication with all parties involved results in low incidence first case delays. Data collection on
accurate timing and reasons for delay will most likely facilitate further improvement in OR efficiency.
Ref:
Wright JG. Can J Surg, 53(3);167-170, 2010
Mariano E. J Clin Anesth, 21(4);253-257, 2009
Funding: This study was funded internally by the Department of Anesthesiology and Perioperative
Medicine and the Perioperative Services at Oregon Health & Science University
A105
RISK FACTORS AND MEDICAL CONSUMPTIONS ASSOCIATED WITH POSTOPERATIVE
NAUSEA AND VOMITING
1
2
2
2
2
2
P.-J. Liao , M.-L. Tsai , C.-Y. Huang , D.-Y. Kerr , T.-S. Huang , C.M. Yang , K.-H. Hsu
1
2
2
Oriental Institute of Technology, New Taipei City, Chang Gung University, Taoyuan, Taiwan R.O.C.
Introduction: Post-operative nausea and vomiting (PONV) is one of the most common side effects
associated with surgical procedures. The incidence of PONV after general anesthesia is about 25% to
30%. PONV can result in negative impacts on medical quality and the subsequent recovery as well as
quality of life. This study aimed to analyze the factors associated with PONV and their medical
consumptions with data from general anesthesia patients.
Materials and methods: The study is a retrospective follow-up design, which collected data from
general anesthetic patients admitted in a medical center from January 1, 2008 to December 31, 2008.
A total of 27,715 study subjects were collected from Quality Assurance database. This study has
obtained patient and Institutional Review Board (IRB) approval. Univariate statistics and a multiple
logistic regression model were applied to explore the factors associated with PONV.
Results: The characteristics of high risk patients were female, aged between 12-18, departments of
gynecology/obstetrics, general surgery, or ophthalmology. Higher incidence was found among adults
using patient controlled anesthesia (PCA) and children using Opioids drugs. The risk of PONV was
reduced when combined prescriptions with antiemetic drugs, such as Dexamethasone, Zofran, and
Kytrill, in some patient groups. The effects of PONV on medical consumptions during hospitalization
were also examined. Elevations of total medical expenses, and total drug expenses were found
between PONV cases and their matched controls, particularly on Propofol users, TIVA users, patients
in department of general surgery, patients aged 61-70, overweight patients, and physicians practicing
less than 10 years.
Discussion: The predictive model constructed by the above mentioned risk factors was helpful in
identification of high risk patients on PONV so that prevention countermeasures could be early
applied. Moreover, this identification of high risk group on PONV offers clues for constructing clinical
guidelines for surgical patient management. The benefits of such management strategy can be found
in both medical quality improvements and cost containments. In addition, the patient safety can be
assured with the clinical decision rules.
References:
1. Darkow T, Gora-Harper ML, Goulson DT, Record KE. Impacts of antiemetic selection on
postoperative nausea and vomiting and patient satisfaction. Pharmacotherapy. 2001;21:540-8.
2. Forrester CM, Benfield DA, Matern DA, Kelly JA, Pellegrini JE. Meclizine in combination with
ondansetron for prevention of postoperative nausea and vomiting in a high-risk population. AANA J.
2007; 75:27-33.
3. Gan TJ, Meyer TA, Apfel CC, et al. Society for ambulatory anesthesia guidelines for the
management of postoperative nausea and vomiting. Anesth Analg. 2007;105:1615-28.
4. Karlsen KL, Persson E, Wennberg E, Stenqvist O. Anaesthesia, recovery and postoperative
nausea and vomiting after breast surgery. A comparison between desflurane, sevflurane and
isoflurane anaesthesia. Acta Anaesthesiol Sacnd. 2000;44:489-93.
5. Kovac AL. Prevention and treatment of postoperative nausea and vomiting. Drugs. 2000;59:21343.
6. Murphy MJ, Hooper VD, Sullivan D, Clifford T, Apfet CC. Identification of risk factors for
postoperative nausea and vomiting in the perianesthesia patient. J Perianesth Nurs. 2006;21:377-84.
Funding disclosure: Nothing to disclose.
Personal conflicts of interest disclosure: Nothing to disclose.
A106
ANTICEPHALGIC PHOTOPROTECTIVE PREMEDICATED MASK: A REPORT OF A
SUCCESSFUL STUDY OF A TREATMENT FOR MIGRAINE AND/OR TENSION HEADACHES
M. Hyson
Neurology, University of Nevada, Las Vegas, NV, USA
Objectives: This study was performed to determine the efficacy of an anticephalgic photoprotective
mask in conjunction with a topical medication containing bryonia and rhus toxicodendron in the
treatment of migraine and/or tension headache.
Background: Many clinicians are seeking headache treatment modalities with improved safety
profiles. A premedicated mask would serve not only as a delivery system for benign topical
medication, but simultaneously provide photorelief and exert external pressure which may alleviate
vascular headaches by collapsing painfully distended extracranial arteries and reducing peripheral
sensitization.
Methods: Thirty-three patients were given masks and tubes of topical medication containing the
bryonia and rhus toxicodendron. They were instructed to apply the medication to their frontalis and/or
temporalis regions in the event they should suffer a headache and apply a photoprotective mask.
Furthermore, they were instructed to take their usual oral or parenteral medications if required for the
relief of the headache. They subsequently filled out forms rating the degree of relief which they
attributed to the topical medication and the mask using a 0-10 scale. At the interview following the
completion of their participation in the study, the patients were also simply asked if this form of
treatment helped or not.
Results: Thirty out of 33 patients stated the medication and the mask were effective over and above
the normal degree of relief they were receiving from their oral and/or parenteral medications. This
study demonstrated a significant efficacy rate (91%) in the treatment of migraine and/or tension
headache with the anticephalgic mask in conjunction with a topical cream containing bryonia and rhus
toxicodendron.
Conclusions: This study demonstrated a significant efficacy rate in the treatment of migraine and/or
tension headache with the anticephalgic mask in conjunction with a topical cream containing bryonia
and rhus toxicodendron.
A107
ULTRASOUND-GUIDED ROOT/TRUNK (INTERSCALENE) BLOCK FOR HAND AND FOREARM
ANESTHESIA
1
1
2
1
1
1
1
1
S. Madison , J. Humsi , V. Loland , P. Suresh , N.P. Sandhu , M. Bishop , M. Donohue , D. Nie , E.
1
1
Furgeson , B. Ilfeld
1
2
Anesthesiology, UC San Diego, San Diego, CA, Anesthesiology, University of Washington, Seattle,
3
WA, UC San Diego, San Diego, CA, USA
Introduction: Historically, the anterolateral interscalene block—deposition of local anesthetic
adjacent to the brachial plexus roots/trunks—has been used for surgical procedures involving the
shoulder. The resulting block frequently failed to provide surgical anesthesia of the hand and forearm,
even though the brachial plexus at this level included all of the axons of the upper extremity terminal
nerves. However, it remains unknown whether deposition of local anesthetic adjacent to the 7th
cervical root or Inferior trunk—now possible using an ultrasound-guided technique—results in
anesthesia of the hand and forearm.
Materials and methods: Using ultrasound guidance and a needle-in-plane posterior approach, a
Tuohy needle was positioned with the tip located between the deepest and next-deepest visualized
brachial plexus root/trunk, followed by injection of mepivacaine 1.5% (Figure 1). Grip strength and the
tolerance to cutaneous electrical current in five terminal nerve distributions were measured at baseline
and then every 5 minutes following injection for a total of 30 minutes. The primary endpoint was the
proportion of cases in which the interscalene nerve block resulted in a decrease in grip strength of at
least 90%, and hand and forearm anesthesia (tolerance to >50 mA of current in all 5 terminal nerve
distributions) within 30 minutes. The primary hypothesis was that a single-injection interscalene
brachial plexus block produces a similar rate of anesthesia of the hand and forearm to the published
success rate of 95% for other brachial plexus block approaches.
[Figure 1]
Figure 1. Ultrasound image of interscalene groove with needle position (arrow) and local anesthetic
spread (asterisks) around the deepest-visualized neural element.
Results: Of 55 subjects with blocks placed per protocol, all had a successful block of the shoulder as
defined by inability to abduct at the shoulder joint. Thirty-three subjects had measurements at 30
minutes following local anesthetic deposition, and only 5 (15%) of these subjects had a surgical block
of the hand and forearm (p< 0.0001; 95%CI: 6-33%). We therefore reject the hypothesis that the
interscalene block as performed in this study provides equivalent anesthesia to the hand and forearm
compared to other brachial plexus block techniques. Block failures of the hand and forearm were due
to inadequate cutaneous anesthesia of the ulnar (n=27; 82%), median (n=26; 78%), or radial (n=22;
67%) distributions; the medial forearm (n=25; 76%), and/or the lateral forearm (n=14; 42%). Failure to
achieve at least a 90% reduction in grip strength occurred in 16 subjects (48%).
[Figure 2]
Figure 2. Sensory (measured by tolerance to cutaneous electrical current) and motor block
(measured by grip strength) 30 minutes following local anesthetic injection.
Discussion: This study did not find evidence to support the hypothesis that local anesthetic injected
adjacent to the deepest brachial plexus roots/trunks reliably results in surgical anesthesia of the hand
and forearm.
References:
1. RAPM. 2009;34:60-3
2. RAPM. 2009;34:3-7.
3. RAPM. 2009;34:498-502.
Funding: NIH GM077026, NIH UL1RR031980, UCSD CTRI and Department of Anesthesiology
Personal conflicts of interest: Nothing to disclose.
A108
A CATHETER-OVER-NEEDLE ASSEMBLY IMPARTS GREATER STABILITY AND REDUCED
RISK OF LEAKAGE ON INTERSCALENE CATHETERS COMPARED TO TRADITIONAL
CATHETER ASSEMBLIES
V.H.Y. Ip, B.C.H. Tsui
Department of Anesthesia and Pain Medicine, University of Alberta, Edmonton, AB, Canada
1
Introduction: Continuous peripheral nerve blocks are susceptible to a number of complications,
including leakage from the catheter insertion site. We recently reported a case where the leakage
2
from a traditional interscalene catheter threatened to contaminate the sterile surgical field. Removal
and replacement with a “catheter-over-needle” (CON) assembly successfully overcame this problem.
In this study, we hypothesized that interscalene CON assemblies are more stable and less prone to
leakage at the insertion site compared to conventional catheter-through-needle (CTN) design.
Material and methods: Following institutional ethics approval and informed consent, patients
scheduled for shoulder surgery or proximal humerus surgery were randomized into control and study
groups. Control group patients received an ultrasound-guided interscalene catheter using the
traditional catheter insertion technique. A 13-6 MHz high frequency linear probe was used to identify
the brachial plexus, and a 19G Tuohy needle was inserted in-plane in a lateral-to-medial direction
between the C5/6 or C6/7 roots. Following hydrodissection with dextrose 5% in water (D5W) and
25mL of local anesthetics, a 20G catheter was inserted through the needle. The catheter was secured
to the patient following needle withdrawal. Study group patients underwent a similar procedure except
that a 21G x 95 mm catheter-over-needle unit was directed in a lateral-to-medial approach between
the C5/C6 or C6/7 roots. Following hydrodissection with D5W and 25mL of local anethetics, the
needle was removed, and an inner catheter was inserted into and Luer-locked to the outer catheter
(Figure).
[CON assembly with the inner and outer catheter]
Both the inner and the outer catheter were in situ and secured to the patient as described above. The
incidence of leakage and dislodgement/remanipulation of the catheter was recorded.
Results: Fifteen patients were recruited for the study: 4 CTN; 11 CON. All CTN patients experienced
leakage around the perineural catheter. One CTN (25%) migrated out on postoperative day one, and
two CTNs (50%) required fortification with gauze to address leakage. One CTN (25%) was removed
pre-operatively due to excessive leakage. In contrast, none of the CON patients experienced leakage
around the catheter, and none required catheter remanipulation or fortification.
Discussion: Our results suggest that interscalene CON catheters are considerably more stable and
less prone to leakage compared to traditional CTN catheters. It should be noted that the number of
patients in the CTN group was disproportionately small since the study was terminated after our
surgical colleagues refused to operate on patients fitted with a CTN catheter due to the unacceptable
risk of leakage contaminating the surgical site.
References:
1. Ilfeld BM. Anesth Analg. 2011; 113: 904-25
2. Ip V et al. Can. J. Anesth. 2012; 59: 1125-9
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society.
Personal conflicts of interest: The Pajunk MultiSet 211156-40E is modified and re-designed by Ban
Tsui. Dr. Tsui also has a patent-licensing agreement with Pajunk.
A109
THE IONOTROPIC AMPA TYPE GLUTAMATE RECEPTOR GLUA4 IS EXPRESSED IN
EPIDERMAL KERATINOCYTES AND HAIR FOLLICLE BULGE CELLS
1
2
2
2
T. Irie , D.C. Ferri , M. Ruiz , D. Owens , J. Moron-Concepcion
1
2
2
3
Anesthesiology, Columbia University, NY, Anesthesiology, Dermatology, Columbia University, New
York, NY, USA
Introduction: Peripheral glutamatergic neurotransmission is important for pathogenesis of pain and
itch1. Ionotropic glutamate receptors (iGluRs) include N-methyl-D-aspartate receptors (NMDARs), αamino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), and kainate receptors
2
(KARs). Mechanosensitive nerve fibers of mammalian pelage hairs express NMDARs , but AMPAR
/KAR expression in the epidermis is poorly described. Here we examine the expression of AMPAR
and KAR in the epidermis of hairy skin and demonstrate unexpected expression of both in
proliferative keratinocytes.
Materials and methods: Dorsum skin of C57BL6 female mice was used in all the experiments.
Immunohistochemical staining for GluA4 was observed using an Eclipse Ti Nikon confocal
microscope. Based on the immunostaining pattern for GluA4, CD34+ keratinocytes were sorted using
Fluorescence activated cell sorting (FACS). RNA from sorted and unsorted cells was extracted by a
hybrid Trizol (Invitrogen)/RNeasy (Qiagen) method and used for OneStep RTPCR (Qiagen). GluA4
and 3 protein expression was assessed using western blotting.
Results: In an experiment designed to explore AMPAR/KAR immunostaining in peripheral nerve
fibers from hairy skin, we observed a prominent expression of GluA4 AMPAR subunit keratinocytes
from the bulge of the hair follicle, generally delineating their surface. In order to confirm GluA4
expression, hair bulge keratinocytes were isolated by FACS as a6-integrin+/CD34+/Sca1- cells,
analyzed by RTPCR for Gria4 transcript (encoding GluA4) and sequence verified. Furthermore,
RTPCR confirmed keratinocyte expression of Gria3, Grik3, and Grik5, but not of Gria1 or Gria2.
Western blots of mouse epidermis revealed immunoreactive bands for GluA4 (50kDa) and GluA3 (50
and 100 kDa), but not for GluA1 or 2. Grik3 or Grik5 were not assessed.
Discussion: The results obtained here provide important insight in keratinocyte physiology and can
have implications for regenerative medicine and hair growth research. stimulation of keratinocytes has
been shown to elicit mechanical hyperalgesia and itch-related responses in mice5. An effect of
AMPAR activation on keratinocyte calcium levels could be key to regulate the release of pruritogenic
and pro-/antinociceptive mediators upon AMPAR timulation. Further research will assess the role of
AMPAR/KAR in itch, hyperalgesia and epithelialization.
References:
1. Larsson, M. and Broman, J. The Neuroscientist. 2012
2. Woo, S-H, et al. Development. 2012
3. Morris, R. J. In Keratinocyte Methods. 1994
4. Trempus, CS, et al. J Invest Dermatol. 2003
5. Caterina, M et al. Neuroscience 2012.
Disclosures: None
Grant support: NIH
A110
BACTERIAL COLONIZATION OF CONTINUOUS PERIPHERAL NERVE BLOCK CATHETERS
1
2
H.K.P. Kalagara , V. Uppal , G. Haldane
3
1
2
Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA, Department of Anesthesia, London
3
Health Sciences Centre, London, ON, Canada, Department of Anesthesia, Hairmyres Hospital, East
Kilbride, UK
Introduction: Continuous peripheral nerve block (CPNB) catheters are being increasingly used for
post-operative pain relief. The incidence of CPNB catheter colonization has been quoted to be 44%, if
signs of local inflammation are present [1]. Colonization of CPNB catheters can lead to morbidity in
the form of local infection, abscess formation or systemic infections [2]. We aimed to find the common
types of bacteria that are responsible for colonization of CPNB catheters.
Methods: After obtaining approval from our institutional clinical governance department, we carried
out a retrospective analysis of our hospital acute pain services database. In our hospital, all the CPNB
catheters (after removal) are routinely sent for microbiological analysis, if signs of local inflammation
are present. The hospital database from June 2002 to December 2010 was investigated for all
positive culture results. The type of bacteria and the site of catheter insertion were noted.
Results: 976 CPNB catheter insertions were recorded in the database during the eight-year review
period. 61 of these showed signs of local inflammation and therefore were sent for microbiological
analysis. Twenty-two CPNB catheters had positive culture results. Five of these had two types of
bacteria cultured, making the total number of bacteria isolated, twenty-seven. Common types of
CPNB catheter inserted were fascia-illiaca, lumbar plexus, para-vertebral and transversus abdominis
plane (TAP) block catheters. Table 1 shows the types of bacteria cultured from various CPNB
catheters.
Bacteria
Staphylococcus epidermidis
Number of cases isolated (percent) N=27
13 (48%)
Methicillin-Resistant Staphylococcus aureus 5 (18%)
Pseudomonas aeruginosa
3 (11%)
Enterobacter cloacae
2 (7%)
Proteus mirabilis
1 (4%)
Klebsiella pneumoniae
1 (4%)
Enterococcus faecalis
1 (4%)
Bacillus
1 (4%)
[Table 1]
Discussion: Results of our study show that Staphylococcus epidermidis is commonest bacterium that
colonizes the CPNB catheters followed by Staphylococcus aureus. The knowledge of bacteria
commonly colonizing the CPNB catheters can be useful in guiding the antibiotic therapy should the
infectious complications occur.
References:
1. Capdevila X, Pirat P, Bringuier S, et al. Continuous peripheral nerve blocks in hospital wards after
orthopedic surgery: a multicenter prospective analysis of the quality of postoperative analgesia and
complications in 1,416 patients. Anesthesiology 2005 Nov; 103(5): 1035-45
2. Capdevila X, Bringuier S, Borgeat A. Infectious risk of continuous peripheral nerve blocks.
Anesthesiology 2009 Jan; 110(1): 182-8
Funding disclosure: Only departmental funds were used for this study. No external funds were
obtained
Personal conflicts of interest disclosure: Nothing to disclose
A111
RETROGRADE LARYNGEAL BLOCK: A NEW TECHNIQUE FOR AWAKE INTUBATION
COMPARED WITH CONVENTIONAL REGIONAL AIRWAY BLOCK
K. Karvandian, S. Sha`bani, J. Zebardast, E. Sadegzadeh
1
2
3
Anesthesiology and Critical Care Unit, Anesthesiology, Imam Khomeini Hospital, Tehran University
of Medical Sciences, Medical School, Tehran, Iran
Introduction: Airway block is a useful method for providing patients comfort and safety during awake
intubation. Retrograde laryngeal block is a new technique that blocks complete supraglottic and glottic
area by introducing catheter retrograde from trachea to these regions.
Methods and materials: This is a clinical trial conducted on two groups each containing 25 patients,
who were candidate for awake intubation. The first group (A) underwent conventional method of
airway block, by multiple injections of local anesthetic. The second group (B) underwent retrograde
laryngeal block as a new method of regional airway anesthesia. In this method the catheter is inserted
from cricothyriod membrane through a flexible guide wire, and then local anesthetic drug will be
administered by direct vision of tip of the catheter by employing glidescope. The catheter has three
separate orifices, each will stay on distinct area of either supraglottic and glottis area which can be
adjusted at any level through these area that is considered to be blocked.
Result: Both groups had hemodynamic stability during performing block. In group A we had two
incidences of laryngospasm due to pain of multiple needle insertion(8%); in group B we had no
incidence of laryngospasm (0%)(p=0.1). In group A we had 5 patients with partial airway block (20%)
which needed further intervention during awake intubation but in group B all the cases had complete
and perfect airway block(100%) (0.001). 22 patients comfort was better in group B (88%) with single
injection than group A(13 patients) with multiple injections(52%) (0.005 ).
Discussion: The advantage of this method is single injection and high quality of block performance in
comparison with the other technique. And the most important advantage is that it can be conducted
for the patients with neck pathologies that make conventional airway block impossible.
Conclusion: This method is safe and practical for airway block. The unique advantage of this
technique is that by remaining the catheter, we can provide continues airway block as long as we
need to keep the patients intubated.
This is of great benefit for the patients intubated in critical care unit . And the most important
advantage of this method over conventional airway block is that, it can be applied in patients with
neck pathologies that make conventional block impossible.
A112
RETROSPECTIVE REVIEW OF EXPAREL IN INFILTRATION-TRANSVERSUS ABDOMINIS
PLANE (I-TAP) BLOCKS IN HAND-ASSISTED NEPHRECTOMY AND COLORECTAL
PROCEDURES
R. Kesha, X. Jacobs, J. Hutchins
University of Minnesota, Minneapolis, MN, USA
Introduction: Infiltration into the transversus abdominis plane is a way to provide analgesia for either
upper or lower abdominal surgery. However, a single shot may only provide analgesic coverage for up
to 18 hours post-injection and patients may experience pain and discomfort beyond that 18 hour
window. Exparel, a multivesicular formulation of bupivacaine, has been shown to provide analgesia
1
for up to 72 hours post-injection .
Methods: This was a retrospective review of 20 patients, 12 hand-assisted nephrectomies and 8
hand-assisted colorectal procedures from October 2012 to December 2012. The infiltrationtransversus abdominis plane or i-TAP blocks were all placed bilaterally under ultrasound guidance in
a pre-operative block area. The i-TAPs were subcostal for the hand-assisted nephrectomies and
classic for the hand-assisted colorectal procedures. Each i-TAP injection consisted of 10 mL of 0.25%
bupivacaine with epinephrine 1:200,000 injected first, immediately followed by a 20 mL 50:50 mixture
of Exparel and normal saline for a total of 30 ml each side. Pain scores were obtained by on a daily
basis. Patient´s were questioned daily about whether they felt relief or numbness in the area of their
incision. Charts were also reviewed to obtain narcotic use, adverse events, and length of stay.
Results: There was no difference in baseline characteristics between the two groups. The mean age
was 49 years (SD 16.702). The mean pain score at rest was 2.3 (SD 1.78), 2.25 (SD 1.88), and 1.95
(SD 1.73) at 0-24 hours, 24-48 hours, and 48-72 hours post-injection. The mean pain score with
movement was 5.25 (SD 2.12), 4.2 (SD 2.26), and 3.0 (SD 1.86) at 0-24 hours, 24-48 hours, and 4872 hours post-injection. The mean narcotic usage in fentanyl equivalents was 362.25 mcg (SD 261),
220.5 mcg (SD 189), and 121.75 mcg (SD 146) at 0-24 hours, 24-48 hours, and 48-72 hours postinjection. The mean length of stay was 3.5 days (SD 1.16). There was no significant difference in pain
scores or opioid usage when the nephrectomy and colorectal procedures were compared. There were
4 patients with nausea and 2 patients developed a wound infection. All 20 reporting affirmatively for
the first 48 hours that they felt numbness at their incision and had varying responses of when they
started to notice a recession of numbness between 48-72 hours. There were no opioid or local
anesthetic related adverse events.
Discussion: These findings suggest that that the use of Exparel in i-TAP blocks is a useful adjunct to
postoperative pain control up to 72 hours post-injection in those patients undergoing hand-assisted
abdominal procedures. This study also suggests a favorable safety profile with no adverse events
related to the use of Exparel in an i-TAP.
Conflict of Interest: J. Hutchins is on speaker´s bureau for Pacira Pharmaceuticals.
References: 1. Gorfine SR, Onel E, Patou G, Krivokapic ZV. Bupivacaine extended-release liposome
injection for prolonged postsurgical analgesia in patients undergoing hemorrhoidectomy: a
multicenter, randomized, double-blind, placebo-controlled trial. Dis Colon Rectum. 2011;54:15521559.
A113
DEXMEDETOMIDINE REDUCES DOSE REQUIREMENT OF THIOPENTONE SODIUM AND
PENTAZOCINE, DECREASES POSTOPERATIVE PAIN AND REDUCES HAEMODYNAMIC
FLUCTUATION
S. Khanduja, A. Ohri, M. Panwar
Anaesthesia, IGMC, Shimla, India
Pain relief forms an important part of anaesthetic management today. Not withstanding the discovery
of effective anaesthetic agents such as propofol and desflurane,they do not appear to have an impact
on postoperative pain and nausea, two of the most common causes of delayed recovery and delayed
1
hospital discharge . Dexmedetomidine is a potent, highly selective α2- adrenoceptor agonist. We
evaluated dexmedetomidine in anaesthetic practice for its sympatholytic, haemodynamic stabilizing,
and analgesic and anaesthetic sparing properties. To study assess the role dexmedetomidine in
reducing dose of sodium thiopentone ,analgesic requirement and decrease in post operative side
effects. Sixty patients of age between 20-65 years, weight 47-70 kg, irrespective of sex for
laparoscopic cholecystectomy under general anaesthesia were included in this single blinded
randomized parallel-group study. The patients were randomly allocated to two groups, Group-A and
Group-B each having 30 patients. Patients who had anemia , used long-term medications or use of
any medication within 1 week before surgery , history of any chronic disease, history of drug abuse,
consumed 30 gm of alcohol daily and abnormal preoperative electrolyte concentrations were
excluded from study. Patients in Group-A received an infusion of normal saline, whereas Group-B
patients received dexmetetomidine by adding 200 microgram of the compound to 38 ml normal saline
making a total volume of 40 ml in microdrip set.. Infusion was started at the rate of 0.5microgram/kg/hr
at 30 min before induction and 0.6microgram/kg/hr thereafter till the end of surgery.. Induction doses
of Sodium thiopentone, analgesic/opioid requirement, post intubation haemodynamic response,
haemodynamic fluctuations and recovery of the patient were noted. Requirement of thiopentone
sodium in males, females and all patients decreased significantly from 3.69±0.23 mg/kg, 3.92±0.324
mg/kg and 3.88±0.318 mg/kg to 2.76±0.467 mg/kg, 2.55±0.184 mg/kg and 2.59±0.267 mg/kg
respectively. Requirement of pentazocine also decreased significantly from 30±5.37 mg, 29.3±4.08
mg and 29.4±4.27 mg to 23.5±6.12 mg, 16.5±1.77 mg and 17.9±4.13 mg respectively. In the control
group, 9 patients (3 males and 6 females) had complained of post- surgical pain. In the test
(Dexmedetomidine) group of 30 patients, 4 (13.3%) complained of post-surgical pain. The most
significant finding is that dexmedetomidine significantly decreased fluctuation in pulse rate/min (.P maxmin ) from 34.8 ± 8.98 to 18.7 ± 6.87, Similarly, values of variation in mean arterial pressure (MAP maxmin ) decreased significantly from 35.6 ± 11.3 to 19.97 ± 6.73(mmhg). Though, the post intubation
pulse (PIP) and post intubation mean arterial pressure ( PIMAP) increased with respect to Pulse30
(PIP-P30) and MAP30 (PIMAP-MAP30), but dexmedetomidine treatment of the patients undergoing
surgery significantly decreased this increase in pulse rate and mean arterial pressure.In short,
dexmedetomidine reduces dose of thiopentone, pentazocine requirement and decreases post
operative pain. Moreover, the fluctuation in pulse rate and mean arterial pressure narrowed down.
1- (Gold et al, 1989.).
A114
COMBINATION FEMORAL NERVE BLOCK AND MULTIMODAL ANALGESIA REDUCES
HOSPITAL LENGTH OF STAY IN PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY
M.R. King, J. Paterno, E.A. Jacob, A.A. Freiberg, R.G. Peloquin, L. Warren, P. Stefanovich, M.
Gargarian, K.H. Fleischmann
1
2
Department of Anesthesia, Critical Care and Pain Medicine, Department of Orthopaedic Surgery,
Massachusetts General Hospital, Boston, MA, USA
Introduction: Both femoral nerve block and multimodal periarticular injections have been shown to
improve pain control following total knee arthroplasty. However, there is less data available on the
effect on recovery and hospital length of stay. We investigate length of stay reduction following one
surgeon's introduction of preoperative multimodal oral analgesics and femoral nerve block, and
intraoperative multimodal injection.
Materials and methods: Seventy patients who underwent unilateral total knee arthroplasty by a
single surgeon (AAF) at Massachusetts General Hospital in 2010 and 2012 were randomly selected
and retrospectively enrolled in the study. Patients who underwent surgery in 2010 prior to this
surgeon's utilization of combined femoral nerve block and multimodal therapy were in the control
group (n=34) and patients who had been operated upon in 2012 and received femoral nerve block
and multimodal therapy were in the test group (n=36). Patients in the control group received either
spinal or general anesthesia for surgery followed by oral and intravenous pain medications
postoperatively. Patients in the test group received general or spinal anesthesia with standard
postoperative pain management. They also received the following: celecoxib 400 mg, oxycodone
continuous release 10-20 mg, and acetaminophen 975 mg po preoperatively, ultrasound-guided
femoral block with 20 mL of 0.2% ropivacaine with 1:400,000 epinephrine, and a periarticular injection
of a multimodal mix consisting of 30 mg ketorolac, 0.5 mg epinephrine, 0.08 mg clonidine, and 246.25
mg ropivacaine mixed in 100 mL normal saline intraoperatively. Statistical calculations were
performed with two-tailed, unpaired t-tests.
Results: Mean hospital length of stay was reduced in the entire test group compared to the entire
control group (2.7 versus 3.3 days, p=0.003). When analyzed by intraoperative anesthetic, the
difference between patients receiving spinal anesthesia with combination therapy (n=19) versus those
receiving spinal alone (n=17) was even greater (2.3 versus 3.2 days, p< 0.0001). Patients receiving
general anesthesia with combination therapy (n=19) saw a trend but no significant decrease in length
of stay when compared to those not receiving combination therapy (n=17; 3.1 versus 3.4 days,
p=0.25).
[Hospital Length of Stay (Days)]
Discussion: In this retrospective study, spinal anesthesia plus combination femoral nerve block and
multimodal analgesic therapy significantly reduced hospital length of stay. Prospective data and larger
sample sizes are needed to confirm these findings.
References:
1. Allen HW, et al. Peripheral nerve blocks improve analgesia after total knee replacement surgery.
Anesthesia and Analgesia, 1998;87(1):93-97.
2. Venditolli PA, et al. A multimodal analgesia protocol for total knee arthroplasty: a randomized,
controlled study. The Journal of Bone & Joint Surgery, 2006;88(2):282-289.
3. Wang H, et al. The Effect of Single-Injection Femoral Nerve Block On Rehabilitation And Length of
Hospital Stay After Total Knee Replacement. Regional Anesthesia & Pain Medicine, 2002;27(2):139144.
Funding and COI: none
A115
IS EPIDURAL-PCA ANALGESIA NECESSARY FOR A THIRD DAY POST CESAREAN SECTION
PAIN
C. Kloepping, S. Cohen, S. Shah, S. Mungekar, A. Mohiuddin, A. Solina, C.W. Hunter
Anesthesiology, Robert Wood Johnson University Hospital - UMDNJ, New Brunswick, NJ, USA
Introduction: Our practice has been to provide epidural-PCA ropivacaine 0.025% with fentanyl 3
mcg/ml & epinephrine 1 mcg/ml for most of our post cesarean section (C/S) patients for 48 hrs. Very
often, patients requested to continue this treatment for another extra day.
rd
Method: We determined if epidural-PCA analgesia is necessary for 3 day post C/S. Following IRB
approval 112 p'ts who received epidural-PCA for post C/S pain for 48 hrs were included. The patients
were given the option to continue this treatment for 72 hrs or to discontinue the treatment at 48 hrs
and receive P.O. oxycodone 5 mg + acetaminophen 325 mg tabs along with ibuprofen 400 tab every
4 hrs PRN. Two groups were identified: G I: 78 p'ts preferred to continue the epidural-PCA treatment;
G II: 34 p'ts preferred to discontinue the epidural-PCA treatment. Values are mean±SD.
Results: The groups did not differ with age, weight, height or parity. The p'ts in GI received epidural
infusion rate of 11.7 ± 7.0 PCA attempts of 24 ± 41 & PCA dose of 13 ± 13 ml. In G II 26 p'ts (76.5%)
regretted their decision to discontinue the epidural-PCA treatment at 48 hrs. Overall satisfactions of
the pain treatments were 9.3 ± 1.6 & 7.6 ± 2.3 (p< 0.00001) for G I& II respectively.
Pain (rest at Pain(ambulation Pain(cough
72 hrs)
at 72 hrs)
at 72 hrs)
Sedation
Nausea
Pruritus
Group I
1.3 ± 2.0
2.5 ± 2.3
3.8 ± 2.8
7 (9%)
5(6%)
23(29%)
Gropup II
2.7 ± 2.6*
4.2 ± 2.9*
5.2 ± 3.0**
13(38%)*
5(15%)
1(3%)^
G I>II:
*p<0.005,
**p<0.03;
^G II<I,
p<0.005.
[Table I]
Conclusions: During 48-72 hrs following C/S most p'ts still complained of pain & requested to
continue the epidural-PCA ropivacaine-fentanyl-epinephrine which provided excellent analgesia with
minimal side effects.
A116
TX360™: A NON-INVASIVE TECHNIQUE FOR SPHENOPALATINE GANGLION NERVE BLOCK
IN THE TREATMENT OF TRIGEMINAL NEURALGIA
K.D. Candido, R. Sauer, L. Chupatanakul, N.N. Knezevic
1
2
Anesthesiology and Pain Medicine, Advocate Illinois Masonic Medical Center, Anesthesiology,
University of Illinois at Chicago, Chicago, IL, USA
Introduction: The sphenopalatine ganglion, located in the posterior part of the middle nasal turbinate,
is involved in pain associated indirectly with trigeminal neuralgia (TGN). Local anesthetic therapeutic
treatment can be provided by using a cotton-tip-applicator approach, hard palate injection or invasive
surgical procedures which might potentially result in development of permanent nerve damage.
Objective: The purpose of this pilot study was to present a novel non-invasive treatment of facial pain
in patients diagnosed by independent neurologists as having TGN, with the nasal applicator™ for
sphenopalatine ganglion nerve block (SPGB).
[Figure 1]
Material and methods: After IRB approval, patients were evaluated for pain using a numeric rating
scale (NRS), modified brief pain inventory, Patient Global Impression of Change (PGIC), and patient
satisfaction. The Tx360™ Nasal Applicator with 1 mL of 0.5% bupivacaine with freshly added
1:200,000 epinephrine were used to perform bilateral SPGB. Pre-procedural evaluations were
repeated post-block at 15 minutes, 30 minutes, and every week up to 28 days post-procedure.
Results: Three female patients, ages 15, 18 and 43 presented with TGN. The average baseline NRS
score was 7 at rest and 9/10 with mastication. All patients had improvement during the first 15
minutes with an average NRS score 2, which persisted to the first day post-procedure. At the end of
the 28 days the average daily pain increased only up to 4 on the NRS. All three patients were
completely satisfied, and the PGIC status was significantly improved on average. One patient
developed minimal bleeding from the nose on the first day which stopped spontaneously in < 5
minutes.
Conclusion: SPGB with Tx360™ provided clinically significant pain relief with minimal complications
in three patients with documented TGN. Modest pain increase during the 28 day follow-up may
indicate the need for repeating the procedure, and evaluating the efficacy of this technique. An
additional seven patients are being screened to assess the technique and gauge its effectiveness
statistically.
A117
PATIENT SATISFACTION WITH GENERAL VERSUS REGIONAL ANESTHESIA FOR
ARTERIOVENOUS ACCESS SURGERY IN PATIENTS WITH END-STAGE RENAL DISEASE
M. Koronfel, P. Loubser, M. Elhakim, B. Marasigan, S. Feng Zhou, K. Charlton-Ouw, A. Azizzadeh
1
2
Anesthesiology, Cardiothoracic and Vascular Surgery, The University of Texas Medical School,
Houston, TX, USA
Introduction: Patients with end-stage renal disease (ESRD) undergoing arteriovenous access
procedures for hemodialysis present multiple challenges for anesthesiologists. (1) Regional
anesthesia (RA) has several theoretical advantages over general anesthesia (GA) and may impact
the actual surgical outcome. (1) However, delivery of effective RA for these procedures requires
planning, additional equipment and education. In addition, anesthetic outcome and patient satisfaction
also require observation, to ensure that quality of care is maintained. In 2010, a RA service for upper
extremity AV access procedures was initiated in this institution (interscalene or supraclavicular
technique). The purpose of this study was to review the initial experiences and patient satisfaction
with this new service; in addition, RA was compared with GA.
Materials and methods: This retrospective study was reviewed and approved by the Institutional
Committee for Protection of Human Subjects. A 9 item survey was conducted by PACU nursing staff
on all patients under- going GA and/or RA during routine follow-up on postop Day 1. The survey
addressed side-effects, satisfaction with anesthetic, duration of recovery and time taken to initiate
activities of daily living, and used scores, Likert scales and narrative descriptors. Where indicated, the
student t-test was used to compare groups using a p value < 0.01 for statistical significance.
Results: Sixty six patients were studied, consisting of 36 undergoing GA and 30 RA. Complete
assessments could not be completed in 13 and 3 patients in the GA and RA groups, respectively. All
stated that they would choose the anesthetic again. Regional block duration was 4.7 ± 0.4 hours.
There were no side effects in the RA group. The GA group rated their experience significantly lower
(2.2 ± 1.1); seventeen percent of patients stated that they would not choose the same anesthetic
again, and 30% experienced side effects ranging from drowsiness to nausea. However, time to
resume activities of daily living was not significantly different between groups.
[Patients' experiences with regional anesthesia]
Conclusions: The findings of this retrospective study demonstrated that patients undergoing RA
experienced significantly better postoperative pain control well beyond the PACU, compared to the
GA group. Patients undergoing RA reported a more satisfactory perioperative experience compared
to the GA group. Side effects following GA were also significantly higher than the RA group. This is
the first study to demonstrate advantages of regional over general anesthesia from a quality of care
standpoint. However, this study was retrospective in nature, and certain variables may have been
operative such as non-randomization of technique and lack of blinding. Therefore, a prospective study
is indicated to address these variables. In addition, this study did not examine surgical factors, such
as duration and outcome of surgery, and correlate these with type of anesthetic, which is a secondary
area for study.
References: Malinzak EB, Gan TJ: Regional anesthesia for vascular access surgery. Anesth Analg
2009;109(3):976-80.
A118
REAL-TIME ULTRASOUND GUIDED APPROACH FOR SPINAL ANESTHESIA
M. Koski, A. Maheshwari, L. Mounir-Soliman, A. Kurz, D.I. Sessler, H. Elsharkawy M.D.
General Anesthesiology, Quantitative Health Sciences and Outcomes Research, Cleveland Clinic,
Cleveland, OH, USA
Introduction: Spinal anesthesia can be challenging in patients with difficult anatomy. Pre procedural
ultrasound has been shown to have promising results (1); however, spinal anesthesia performed with
real time ultrasound guidance has not been studied in patients with presumed difficult anatomy.
Methods: Fourteen patients with presumed difficulty for spinal blockade undergoing elective total joint
arthroplasty of the lower extremity were selected for ultrasound-guided block between April, 2012 and
August 2012 after IRB approval and informed consent. Patients with any one of the following were
2
included; age ≥ 55, BMI > 40 kg/m , or a history of scoliosis. Each spinal block was performed by 1 of
5 staff anesthesiologists who had limited experience with ultrasound-guided neuraxial anesthesia, yet
were well experienced providing peripheral nerve blocks via US. The spinal blocks were performed in
the sitting position with standard ASA monitors in place, while 1-2 mg of IV midazolam was
administered. The blocks were done practicing standard sterile technique with a curved-array 2-5
MHz transducer. The lumbar spine was visualized in both midline and paramedian views. The
locations of the interlaminar spaces were identified by visualizing the ligamentum flavum-dura mater
complex and the posterior aspect of the vertebral body (Figure 1). Paramedian needle insertion was
guided in real time by ultrasound imaging. The scanning of each patient's anatomy was standardized,
including four views and the quality of visualization of the needle tip evaluated by the operator on a
scale of excellent to no visibility at all. Outcomes were reported with concurrent with patient care as
reported below.
Results: The average time to perform the block was 4:15 minutes +/- 0.09 seconds. This time did not
correlate with age, sex or BMI. Operator difficulty rating correlated linearly with time to perform the
block but did not correlate well with patient characteristics such as, BMI and age. All patients rated
their experience 5/5 (extremely satisfied), except for one (3/5). Vertebral level based on landmark and
palpation was wrong 35.7% of the time as compared to level determined by ultrasound visualization
scanning up from sacrum. Depth of the dura complex as determined by ultrasound had a large
variability and did not correspond well with actual depth as measured by needle length inserted to get
CSF. There were no cases of post dural puncture headache, back pain or infection.
Discussion: Real time ultrasound is a feasible technique for spinal anesthesia in patients with
presumed difficulty. The data from this study can be used to plan a randomized controlled study to
evaluate the comparative effectiveness of real time ultrasound guidance as compared to the standard
landmark based technique in patients with difficult spinal anatomy.
References: 1. Chin, K.J., et al., Ultrasound imaging facilitates spinal anesthesia in adults with
difficult surface anatomic landmarks. Anesthesiology. 115(1): p. 94-101.
Funding: Funded internally by the Department of General Anesthesia and Outcomes Research,
Cleveland Clinic.
[Figure 1: Ultrasound image of L3 - L4 spinal block]
A119
ENHANCED RECOVERY FOR KNEE AND HIP ARTHROPLASTY: HAS 2% HEAVY PRILOCAINE
A PLACE - OUR EXPERIENCE
M. La Malfa, B. Korba, B. Hargitai, P. Kocsis, B. Mavrodiev, J. Hamza, S. Dinev, O. Kovacs, K. Alexa,
L. Levy, C. Flower, M. Jacob
1
2
Anaesthetics, Physiotherapy, UK-SH, Emersons Green NHS Treatment Centre, Bristol, UK
Background and aims: Enhanced recovery protocols do improve the quality of care and the clinical
outcomes for the joint replacement patients.The aim of this audit was to evaluate the impact of the
use of spinal 2 % heavy prilocaine on our multidisciplinary recovery program in terms of pain
management, early mobilisation and discharge from the hospital.
Methods: 160 patient were included ( 77 THR and 83 TKR ), Asa 1,2 and stable 3, age was not an
exclusion criteria. The anaesthetic was standardised, so was the peri and post operative drug and
fluid management . 55 TKR and 34 THR patients recieved spinal H. prilocaine, 28 TKR and 23 THR
recieved H. marcaine.
The parameters considered were patient´ s time of first mobilisation,bromage score, average pain
score, ponv,diziness/fainting, knee and hip range of movement, wound oozing, hospital length of stay.
All patients received our enhanced recovery protocol.
Results: 67 patients were male, average age was 69.38.
Success of early mobilisation was 63% in the Prilocaine group, 56.3 % in the Marcaine group. At first
mobilisation, systolic BP was below 100mmhg in only 28% of the patients in the prilocaine group vs
40% within the marcaine group.
Nausea, diziness and ponv were similar within the two groups so as the average pain score (VAS).
Conclusions: 2% Heavy prilocaine permits early mobilisation and it is reccomended in patients with
several co-morbidities where stable peri-operative haemodinamic status is desirable. Patient
satisfaction is extremely high and hospital lenght of stay reduced
References:
1. Br J Anaesth. 2010 May;104(5):582-6. Urinary retention after spinal anaesthesia with hyperbaric
prilocaine 2% in an ambulatory setting.Kreutziger J, Frankenberger B, Luger TJ, Richard S, Zbinden
S.
2. Br J Anaesth. 2011;106(2):183-188. Spinal Anaesthesia for Ambulatory Arthroscopic Surgery of the
Knee: A Comparison of Low-dose Prilocaine and Fentanyl with Bupivacaine and FentanylA. S. Black,
G. N. Newcombe, J. L. Plummer, D. H. McLeod, D. K. Martin
4. Acta Orthop. 2011 Oct;82(5):577-81. Enhanced recovery program for hip and knee replacement
reduces death rate. Malviya A, Martin K, Harper I, Muller SD, Emmerson KP, Partington PF,
5. Arch Orthop Trauma Surg. 2012 Aug;132(8):1153-63. Pathway-controlled fast-track rehabilitation
after total knee arthroplasty: a randomized prospective clinical study evaluating the recovery pattern,
drug consumption, and length of stay. den Hertog A, Gliesche K, Timm J, Mühlbauer B.
A120
PREPUNCTURE SCANNING FOR THORACOLUMBAR PARAVERTEBRAL BLOCKS
1
1
2
1
1
1
1
N.C.K. Lam , J. Higgins , E. Mariano , T.R. Petersen , N. Gerstein , E.E. Szabo , F. Jaime , N.
1
Doran
1
Department of Anesthesiology and Critical Care Medicine, University of New Mexico, Albuquerque,
2
NM, Department of Anesthesiology, Stanford University, Stanford, CA, USA
Introduction: Inguinal hernia surgery can result in moderate to severe pain, which affects daily
1
activities. It has been suggested that inadequate pain control in the postoperative period is
2
associated in the development of chronic groin pain.
When comparing paravertebral block to combined peripheral nerve blocks and local infiltration for
postoperative analgesia, it has been shown that patients with paravertebral blocks experienced
superior dynamic pain control and had reduced postoperative nausea and vomiting in the recovery
3
area.
Ultrasound has been used for pre-puncture scanning for thoracolumbar paravertebral regional
4
anesthesia resulting in improved transverse process depth estimation. However, there are no studies
investigating if the use of ultrasound reduces post-operative analgesic requirements.
Methods: After IRB approval, all patients 18 years and older who underwent unilateral hernia surgery
repair with a T11-L2 paravertebral block within the period from March 1, 2011 through August 31,
2012 at a single outpatient surgical center were included in the study.
Patients who had a documented history of opioid abuse or were on chronic opioid therapy during the
preceding 3 months were excluded.
This criteria resulted in data collection of 143 surgeries from 143 patients.
Equianalgesic opioid conversions were performed to an equivalent dosage of intravenous morphine
5
using standard conversion guidelines. Patients who underwent prepuncture ultrasound scan for
lumbar paravertebral blocks were compared with patients where landmark based lumbar
paravertebral blocks were used.
The primary endpoints measured between the two groups were differences in total narcotic and
postoperative opioid requirements and differences in preoperative versus postoperative pain scores.
Results:
Postop
Preop pain
pain
Median
Median
(IQR)
(IQR)
Intraop
Preop Total
Total
Narcotic
Narcotic
Median
Median
(IQR)
(IQR)
Postop
Total
Narcotics
Median
(IQR)
Total
Narcotics
Median
(IQR)
Ultrasound
0(0,0)
prepuncture
2(0,5)
10(10,10)
0(0,10)
0(0,3.1)
16.3
(10,20.6)
Landmark
0(0,1)
2(0,5)
10(10.10)
5(0,10)
2.5(0,7.5)
20 (11,24)
P value
0.23
0.72
0.94
0.24
0.27
0.07
[Results of Prepuncture Scan vs Landmark technique]
Discussion: There is a tendency for patients with landmark based paravertebral blocks to need more
analgesics intraoperatively, postoperatively, and in total, but none are significant with this 143-patient
sample. Prepuncture ultrasound in paravertebral blocks for inguinal hernia does not reduce postoperative analgesia requirements
References:
1) Callesen T, Bech K, Nielsen R, Andersen J, Hesselfeldt P, Roikjaer O et al. Pain after groin hernia
repair. Br J Surg 1998; 85: 1412-1414
2) Aasvang EK, Gmaehle E, Hansen JB, Gmaehle B, Forman JL, Schwarz J et al. Predictive risk
factors for persistent postherniotomy pain. Anesthesiology 2010; 112: 957 - 969
3) Klein SM, Pietrobon R, Nielsen KC, Steele SM, Warner DS, Moylan JA et al. Paravertebral somatic
nerve block compared with peripheral nerve blocks for outpatient inguinal herniorrhaphy. Reg Anesth
Pain Med 2002; 27: 476 - 480.
4) Ilfeld, Brian M., Vanessa J. Loland, and Edward R. Mariano. "Prepuncture Ultrasound Imaging to
Predict Transverse Process and Lumbar Plexus Depth for Psoas Compartment Block and Perineural
Catheter Insertion." Anesthesia & Analgesia 110.6 (2010): 1725-728.
5) Gordon, Debra B., Karen K. Stevenson, Juliann Griffie, Sandy Muchka, Cathy Rapp, and Kate
Ford-Roberts. "Opioid Equianalgesic Calculations." Journal of Palliative Medicine 2.2 (1999): 209-18.
A121
2% HEAVY PRILOCAINE FOR PRIMARY LOWER LIMB JOINT ARTHROPLASTY IN AN
ENHANCED RECOVERY SETTINGS
B. Lassota-Korba, M. La Malfa, J. Hamza, J. Va Faye, C. Flower, B. Hargitai, B. Mavrodiev, L. Levy,
P. Kocsis, S. Dinev
Anaesthetics, United Kingdom Specialist Hospitals, Bristol, UK
Introduction: Lower limb total joint arthroplasty is one of the most commonly performed orthopaedic
surgical procedures worldwide and enhanced recovery protocols in a multidisciplinary settings have
been introduced to maximise benefits of early mobilisation (such as VTE), reducing anaesthetics side
effects/complications, minimising post operative pain and reducing length of stay in this cohort of
patients.
2% Heavy Prilocaine has recently been introduced in the United Kingdom. It has been claimed that it
confers a shorter duration of action when used in spinal anaesthesia. We have devised a study in
order to ascertain the safety and effectiveness in use of heavy prilocaine as part of our existing
enhanced recovery setting.
We collected the data in order to establish the best approach in management of this group of patients,
to analyse consequences and to set up the best possible patient management. Intra-operative
feedback from surgeons was also sought to find any difficulties posed with regards to muscle tension
during the surgery due to incomplete muscle relaxation.
Material and methods: We evaluated 100 consecutive patients undergoing total hip or total knee
replacement surgeries under spinal anaesthetic using combination of 2% heavy Prilocaine 50mg,
Fentanyl 30 mcg and Morphine 150 mcg. We have implemented the standardized protocol and
assessed the onset of and the resolution of the spinal block using the Bromage score, the time of first
mobilization from surgery, PONV, pain, hemodynamic stability and intra-operative surgeon feedback
score. We also collected data on post operative complications.
Results: We have preliminarily analyzed 100 cases. The average age of patient was 70.53, the
average ASA score was 1.71. The average time to reach the Bromage Score of 4 was 5.61 minutes.
Average VAS score on day 0 was 0.18 out of 10, on day 1 was 1.72, on day 2 was 1.40. 23% of
patients experienced transient mean BP drop of < 65mmHg during surgery when TCI Propofol
sedation was used and in 16% a nominal single dose vasoconstrictor was used. PONV experienced
was 7%, minor itching was noticed in 5% of patients. 63% of patients were mobilized on the day 0
within 6 hours from end of surgery and 94% on day 1. The average length of stay was 2.94 days (the
range 1 - 4 days). There were no major post operative anaesthetic or orthopaedic complications or
mortalities in a six month period.
Discussion: Our results demonstrate that 2% Heavy Prilocaine is safe and contributes significantly to
efficient and effective enhanced recovery of patients undergoing lower limb primary joint arthroplasty.
In our multidisciplinary setting, patients undergoing joint arthroplasty had excellent clinical outcomes,
shorter lengths of stay and minimal complications.
A122
PREOPERATIVE CATASTROPHIZATION SCORE AS A PREDICTOR OF DYNAMIC ACUTE PAIN
INTENSITY AFTER TOTAL KNEE ARTHROPLASTY (TKA)
P.M. Lavand'homme, I. Grosu, E. Thienpont
1
2
Anesthesiology, Orthopedic Surgery, Cliniques Universitaires Saint Luc, Brussels, Belgium
Background: Catastrophization is a negative mental set increasing pain intensity and emotional
distress during painful stimulation (1). TKA a major but common orthopedic surgery is associated to
severe postoperative pain (2). Because early mobilization is mandatory to successful rehabilitation
after TKA, it might be of interest to target patients who will suffer more severe pain, particularly at
movement.
Material and methods: After IRB approval and informed consent, patients undergoing primary TKA
filled in preoperatively the French version of original Sullivan's Pain Catastrophization Scale (PCS)
with subscales of magnification (M PCS), rumination (R PCS) and helplessness (H PCS). A single
surgeon performed all surgeries under standardized anesthesia protocole with postoperative
multimodal analgesia. Postoperative pain scores were recorded from day1 to day7 (VAS 0-10) at rest
(PAR) and for movement evoked pain (MEP). Statistical analysis used unpaired t-tests and Pearson's
correlation, p< 0.05 was significant.
Results: 94 patients were included, age 66±9 yrs, median PCS value 12 (IQR 5-20). For data
analysis, patients were separated in 2 groups: high PCS >12 (n=45; value 19.5, IQR 14-30) and low
PCS < 12 (n=49; value 5, IQR 3-9). High PCS patients had significantly higher postoperative pain at
mobilization from day3 to day7 (figure expressing the increase of pain during mobilization, as
MEP/PAR (2)). Preoperative PCS positively correlated with MEP at day7 (r=534;p=0.0004), as well as
M PCS, R PCS and H PCS dimensions. H PCS also correlated with MEP intensity at day3 and day4.
No correlation was found between PCS and PAR intensity.
[Postoperative dynamic pain after TKA]
Discussion: The results confirm that preoperative PCS value may be an interesting predictor of
severe postoperative pain, specifically for pain during mobilization. Similar observation has already
been reported for different procedures including major spinal orthopedic surgery (3).
References:
(1) Sullivan M et al, Clin J Pain 2001;
(2) Srikandarajah & Gilron, Pain 2011;
(3) Papaioannou M et al, Pain Med 2009.
A123
TAP BLOCK FOR PERITONEAL DIALYSIS CATHETER PLACEMENT, REMOVAL, OR REVISION
K. Lebak, K. Schroeder, M. Donnelly
Department of Anesthesiology, University of Wisconsin, Madison, Madison, WI, USA
Introduction: We evaluated the impact of a pre-operative transversus abdominis plane (TAP) block
on the perioperative course in adult patients undergoing peritoneal dialysis (PD) catheter placement,
removal, or revision at a university hospital-based ambulatory surgery center. We wanted to
determine if a TAP block allowed us to reliably avoid general anesthesia (GA) and was effective in
reducing postoperative pain scores, time to discharge from the recovery room (PACU), perioperative
opioid use, and postoperative and postdischarge nausea and vomiting. Additionally, because a TAP
block for PD catheter surgeries is not well described in the literature, we wanted to determine if there
was an increased incidence of adverse events or unplanned admissions associated with this
anesthetic technique.
Materials and methods: We retrospectively evaluated all ambulatory patients who presented for PD
catheter placement, removal, or revision and compared the perioperative course between patients
who received a preoperative TAP block (TB) and those who had no tap block (NTB). All PD catheter
patients from Jan 1, 2007-Sept 1, 2012 were identified through our billing service. A total of 110 adult
patient surgeries (93 patients) were identified with 104 surgeries (90 patients) analyzed. Three patient
charts, equaling 6 procedures, were unable to be located in a reasonable amount of time, thus were
excluded from the analysis.
Results: Forty-three surgeries were placement of catheters, 56 removal, and 5 revisions. Eight
surgeries had a preoperative TAP block with 6 combined with sedation anesthesia (none converted to
GA) and 2 received planned general anesthesia (due to laparoscopic technique in placing catheters).
There were no adverse events in the TB group, but there was one unplanned admission for
observation.
There were no differences in age, gender, BMI, ASA score, preoperative opioid use, anesthesia time,
total operating room time, surgery time, PACU time, Phase II time, or postoperative nausea and
vomiting between the TB and NTB groups. There was a trend towards a significant difference in
Phase II peak pain scores (p=0.08) and postoperative opioid use.
Discussion: TAP blocks have been used successfully for pain control for a variety of surgeries.
Varadarajan et al. described a TAP block combined with a rectus sheath block for peritoneal dialysis
1
catheter placement. To our knowledge this is the first report of TAP blocks used alone for PD
catheter surgeries.
Limitations of this study include an absence of randomization and a small number of TAP blocks.
There was a potential for difference if more patients were studied namely in the TAP group.
Importantly, there were no differences in anesthesia, total operating room, or surgery times between
the two groups which can often be a concern of surgeons and thus a barrier to surgeons requesting
regional anesthesia.
References: 1. Varadarajan, Y and Balasubramaniyam, R. Ultrasound guided rectus sheath and
transversus abdominis plane block (TAP) for continuous ambulatory peritoneal dialysis (CAPD)
catheterization-our experience. Nephrol. Dial. Transplant. (2012) 27 (suppl 2): ii457-ii482. This article
appears in: 49th ERA-EDTA Congress, May 24-27, 2012, Paris, France.
Disclosure: There is nothing to disclose from any of the authors.
A124
EFFECT OF SYRINGE SIZE ON OPENING INJECTION PRESSURES
1
2
2
1
3
4
E. Lin , C. Vandepitte , K. Buyse , J. Gadsden , I. Hasanbegovic , X. Sala-Blanch , P. Gautier
1
2
5
3
St. Luke's Hospital Center, New York, NY, USA, University Hospitals Leuven, K.U.L., Department
4
of Anesthesiology, Katholieke Universiteit Leuven, Leuven, Belgium, St. Luke's-Roosevelt Hospital
5
6
Center, Columbia University College of Physicians & Surgeons, New York, NY, USA, Institue of
7
Anatomy, University of Sarajevo, Sarajevo, Bosnia-Herzegovina, University Hospital Barcelona,
8
Barcelona, Spain, Clinique Ste Anne-St Remi, Brussel, Belgium
1
Introduction: High opening injection pressure (> 15 psi) can detect needle-nerve contact. However,
the reliability of injection pressure monitoring to detect needle-nerve contact or impingement may be
affected by syringe size. We hypothesized that monitoring of opening injection pressure (the pressure
at which injectate is detected by US) is affected by the size of the syringe used for injection.
Methods: After Ethics Committee approval (KU Leuven, BE), 22 gauge 50 mm needles (Stimuplex-A,
B Braun, Inc) were inserted under US to contact the C5, C6 and C7 nerve roots in fresh frozen human
cadavers. Hand-held injections were made using 3 different syringe sizes (5, 10, 20 mL) at a rate
commensurate with typical clinical practice. Injections were made bilaterally at each of the above
nerve roots. Opening injection pressure data were acquired with an in-line digital pressure recorder
using a 60 ml syringe (10 ml/min), and injection halted when spread was detected.
Results: A total of 48 injection measurements were made. The peak (opening) pressures at which
injection commenced are displayed in the table. Opening injection pressures were similar regardless
of syringe size (p>0.05), or method of injection (hand-held versus automated pump) (p>0.05).
Automated Pump
Injection
Hand-Held Injections
Syringe Size
5cc (n = 12)
10cc (n = 12)
20cc (n = 12)
60cc (n = 12)
Cadaver 1
30.50
29.2
26.03
23.42
Cadaver 2
34.07
34.95
29.42
34.03
[Mean Peak Opening Injection Pressures (psi)]
Discussion: The size of the syringe commonly used in clinical practice of PNBs did not significantly
affect the monitoring of the open injection pressure. All injections with the needle-nerve contact
resulted in injection pressures ≥20 psi, regardless of syringe size or method of injection. Our findings
are thus consistent with the fluid mechanics described by Pascal's Law, where pressure exerted
anywhere in a confined incompressible fluid system is transmitted equally throughout until the
opening pressure is reached and injection begins. Pascal's Law also states that pressure remains
constant throughout the syringe, needle and tubing until the flow of fluid begins, regardless of the
syringe size, speed of injection or diameter of fluid passages.
References:
1. Kapur, E., Vuckovic, I., Dilberovic, F., Zaciragic, A., Cosovic, E., Divanovic, K.-A., Mornjakovic, Z.,
Babic, M., Borgeat, A., Thys, D. M. & Hadzic, A. Neurologic and histologic outcome after intraneural
injections of lidocaine in canine sciatic nerves. Acta anaesthesiologica Scandinavica 51, 101-7
(2007).
A125
REGIONAL ANAESTHESIA - IS IT WHAT PATIENTS WANT? A PROSPECTIVE AUDIT OF
PATIENT PREFERENCE AFTER AXILLARY BLOCK FOR HAND TRAUMA
J. Mathers, D. Patel, A. Hayward
Department of Anaesthetics, Royal Free Hospital, London, UK
Introduction: As clinicians we often feel regional techniques are best for upper limb surgery as it
1
offers excellent analgesia, swifter theatre throughput and reduced costs for upper limb surgery .
However, it is not always known what patients would prefer when given the choice of regional over
general anaesthesia.
Material and methods: 48 patients undergoing regional anaesthesia for corrective hand trauma
surgery under axillary block with sedation were followed up the day after surgery by telephone to give
feedback on their experience and also whether they would choose to have general or regional
anaesthesia for the same surgery. All axillary blocks were performed by a single operator using a
standardized technique with midazolam (max 4mg) and alfentanil (max 600mcg) IV sedation titrated
to effect. Axillary blocks were performed awake with ultrasound and nerve stimulator guidance. At any
point patients could refuse regional anaesthesia and choose a general anaesthetic.
Results: None of the patients had previous experience of upper limb regional blocks. None of the
patients requested a general anaesthetic. There were no block failures and no coversions to general
anaesthesia or requirements for block top-ups. 29 patients had previously had general anaesthetics,
of those only one would have preferred a general anaesthetic to a block. All 19 patients who had not
had general anaesthetics preferred a regional technique. Overall 98% of patients prefer a regional
technique.
Discussion: Regional anaesthesia is known to increase theatre efficiency and provide optimal
analgesia but to provide patient-centered care where possible we should provide the anaesthetic that
patients prefer. Without prior experience patients can only make decisions based upon limited
information. We have identified that patients prefer regional anaesthesia to general anaesthesia for
hand surgery.
References: 1. Horn J et al. Comparison of efficiency, recovery profile and perioperative costs of
regional anaesthesia vs. general anaesthesia for outpatient upper extremity surgery. European
Journal of Anaesthesiology 2007; 24: 557-559
Funding disclosures: No funding was received for this audit
Personal conflicts of interest disclosure: Nothing to disclose
A126
THE PERIOPERATIVE MANAGEMENT OF BILATERAL TOTAL KNEE ARTHROPLASTY
PATIENTS: THE RESULTS OF THE CONSENSUS CONFERENCE ON BILATERAL TOTAL KNEE
ARTHROPLASTY GROUP
1
1,2
1
1
1
S.G. Memtsoudis , O. Stundner , M. Mazumdar , M. Urban , A. Gonzalez Della Valle , L.A.
1
1
Poultsides , T.P. Sculco
1
Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell
2
University, New York, NY, USA, Department of Anesthesiology, Perioperative Medicine and Intensive
3
Care Medicine, Paracelsus Medical University, Salzburg, Austria, Division of Biostatistics and
4
Epidemiology, Department of Public Health, Department of Orthopedic Surgery, Weill Medical
College of Cornell University, New York, NY, USA
Introduction: Considerable controversy exists surrounding various aspects of simultaneously
performed bilateral total knee arthroplasty (BTKA). Despite the notion that this procedure may be
associated with increased risk of complications compared to a unilateral total knee arthroplasty (TKA),
no consensus on appropriate patient selection and management among perioperativ clinicians exists.
As this topic is of immediate importance to anesthesiologists taking care of this patient population, the
purpose of this manuscript is to present the results of a recent meeting of the Consensus Conference
on Bilateral Total Knee Arthroplasty Group, comprised of national experts, that examined various
issues related to BTKA.
Material and methods: After selection of a multidisciplinary group of experts in the fields of
anesthesiology, orthopedic surgery, perioperative medicine and epidemiology, the major questions
surrounding same stage BTKA were addressed by utilizing an extensive literature review and the
modified Delphi process. The year-long process concluded with a meeting of participants and the
formulation of consensus statements.
Results: While more detailed consensus was reached on a number of topics, in brief, the consensus
group agreed that physicians and hospitals should consider using conservative patient selection
criteria in order to mitigate the increased risk for complications associated with same stage BTKA.
Consideration should be given to the fact that BTKA is a more invasive and complex procedure
compared to UTKA and perioperative assessment and management should reflect the higher level of
acuity.
If a patient is not deemed a candidate for same stage BTKA sufficient time should be allowed for the
reversal of the physiological insult of surgery and recovery of organ systems between procedures.
While in some cases orthopedic indications may favor BTKA, these indications should not override
medical concerns, except in extremes of circumstances. In all cases of BTKA a thorough discussion
with the patient about risks, benefits and alternatives should take place prior to proceeding with
surgery.
Discussion: Same stage BTKA poses specific challenges and a systematic approach to the
management of patients should be taken in order to minimize complications. Careful patient selection
and comprehensive perioperative care is important to minimizing perioperative risk.
A127
THE EFFECT OF INTERSCALENE BRACHIAL PLEXUS BLOCK ON THE PULMONARY
FUNCTION OF OBESE PATIENTS
H. Monroe, M.S. Melton
Anesthesiology, Duke University Medical Center, Durham, NC, USA
Introduction: Interscalene block (ISB) of the brachial plexus is a regional anesthetic technique for
shoulder surgery. A normal side effect is an ipsilateral hemidiaphragmatic paresis. Previous work in
healthy, non-obese subjects demonstrated that this resulted in a 25% reduction in pulmonary function.
Due to their baseline restrictive pathology, obese patients may be at greater risk for pulmonary
impairment following ISB. The primary objective of this prospective cohort study was to evaluate the
effects of ISB and associated transient hemidiaphragmatic paresis on the pulmonary function of
obese patients, compared with a non-obese population. This study tested the hypothesis that obese
patients have a larger decrease from baseline pulmonary function tests (FEV1 and FVC) compared
with non-obese patients.
Methods: Fifteen subjects presenting for ISB for elective shoulder surgery at the Duke Ambulatory
Surgical Center (ASC) have been enrolled to date. Prior to ISB placement baseline data was
obtained, including bedside FEV1 and FVC measurements in the sitting and supine position
(handheld spirometer (Micro Medical, Kent, England), diaphragm function (assessed by ultrasound),
and subjective symptoms of dyspnea (Borg dyspnea score). Ultrasound guided ISB was then placed.
All measurements were repeated at 15 and 30 minutes after ISB placement, and again in the
postanesthesia care unit (PACU). Normal BMI and obese groups were compared with exact chisquared tests for categorical values and 2-group t-tests for numeric measures. Comparisons between
pre-block and post-block data at each time period, for both FEV1 and FVC, for the entire study
population were made using paired t-tests. A repeated-measures analysis was used to compare raw
change and percent change in FEV1 (sitting) over all times between groups.
Results: The two cohorts had similar demographic data. There was 100% ipsilateral
hemidiaphragmatic paresis in both groups at all post-block time periods. When the cohorts were
compared there was no significant difference between the two in baseline pulmonary function
(smallest p=0.7745). However, compared with the normal BMI group, the BMI >30kg/m² group was
found to have a significantly greater percent decrease from baseline for measurements of sitting
FEV1 and FVC at 15 and 30 minutes post-block (figure 1).
[figure 1]
These results were confirmed in the repeated-measures analysis for FEV1. No significant difference
was seen between the groups for percent change in function for the supine position at any time point
(smallest p=0.0797), or for any measurements in the PACU (smallest p=0.1194).
Discussion: This prospective study provides evidence that the decrease in pulmonary function
following ISB may be worse in obese patients, particularly during the 30 minutes after the procedure.
However, significantly larger decreases from baseline were not seen for obese subjects in the PACU.
This may support the conclusion that ISB in the ambulatory setting is equally safe for obese and nonobese patients. Recruitment for the study is ongoing, and more information is still needed.
References: Urmey WF, McDonald M. Hemidiaphragmatic paresis during interscalene brachial
plexus block: effects on pulmonary function and chest wall mechanics. Anesth Analg 1992;74:352-7.
Disclosures: Nothing to disclose.
A128
ULTRASOUND IDENTIFICATION OF ANTERIOR SCIATIC NERVE: A COMPARISON IN
TRANSVERSE AND LONGITUDINAL AXIS
E. Monzó, G. Ruiz, E. Abad, M. Hajro, F. Galindo
Anaesthesiology, Fremap Hospital, Majadahonda-Madrid, Spain
Introduction: The anterior approach of the sciatic nerve is used especially in patients in which the
change to decubitus lateral or prone position, is not suitable or is not feasible. With ultrasounds and
the usual position of the probe (cross section), the nerve is displayed as an hiperecoic oval structure.
It is sometimes difficult to identify by the depth of the thigh muscles and it can be hidden by the lesser
trochanter. The image of the nerve in the longitudinal section, improved considerably, appears as a
long cable-like structure with a characteristic fascicular pattern, without the interposition of the lesser
[1]
trochanter
Objective: Compare ultrasound identification of anterior sciatic nerve, in transverse and longitudinal
axis.
Material and method:
Age mean
Weight mean (Kg) Height mean (cm) BMI mean
20 Male
41.71 ±10.81
86.66 ±9.99
175.2 ±0.05
28.21 ±3.04
10 Female
50.11 ±8.43
70.55 ±11.36
160 ±0.05
27.65 ±4.62
[Table]
In thirty patients (table) scheduled for lower limb orthopaedic interventions, we performed a combined
sciatic and femoral block, choosing the anterior approach of the sciatic nerve. The patients were laid
in supine with the lower limb in neutral position. Convex probe of low-frequency 2-5 MHz was placed
in the anteromedial side of the upper thigh, 8-10 cm below the groin. We started the identification of
the sciatic nerve in the transverse axis (Figure 1)
[Figure 1]
and subsequently in the longitudinal axis (Figure 2).
[Figure 2]
The punction was performed either "in plane" or "out plane", associating neurostimulation to 0.8mA.
We injected 20 ml of mepivacaine 1.5%.
Results: Of the 30 patients in which the probe was applied transversely to the thigh, in 22 (73,33%),
we identified the oval hiperecoic image of the sciatic nerve. In the other 8 cases (33,33%),it was not
possible to catalog any suggestive nerve image. With the probe applied sagittaly, it was achieved in
all cases (100%) P=0,2; identifying an hyperechoic cable-like image running through the screen side
by side, corresponding to the sciatic nerve. The block was successful in 29 cases (96,66%).
Conclusion: The ultrasound identificationanterior sciatic nerve in the longitudinal axisis easier than in
the transverse axis. The approximation and localization with the needle, as well as the spread of local
anesthetic, are more evident in the longitudinal axis.
[1]
Tsui BC, Ozelsel TJ. Ultrasound-guided previous sciatic nerve block using a longitudinal approach:
"expanding the view". Reg Anesth Pain Med. 2008 May-Jun; 33 (3): 275-6 doi:
10.1016/j.rapm.2007.11.008.
A129
FIVE YEAR COMPARATIVE ANALYSIS OF PATIENTS PERCEPTION OF PAIN IN HOSPITALS IN
UNITED STATES
A. Nairizi, A. Gupta
Anesthesiology, Drexel College of Medicine, Philadelphia, PA, USA
Limited data are available regarding the quality of pain care in the hospitalized patient. In January
2012, the results of the Hospital Consumer Assessment of Healthcare Providers and Systems
(HCAHPS) survey were released for review for health care providers and researchers. This survey
includes a battery of questions for patients upon discharge from the hospital including pain-related
questions and patient satisfaction that provide valuable data regarding pain care nationwide from
October 2006 to March 2011. This study reviewed the results from the pain questions from this
available data set and evaluate the performance of these hospitals in pain care in relationship to
patient satisfaction. The data indicates that from 2006 to 2011, in average 68.5 % of patients gave a
high global rating for their care, and that an additional 24.1% of patients felt that they usually received
a high quality of care. When correlated to pain, we found that the relationship with overall hospital
rating and always good pain control was moderately correlated (r > 0.55). In respect to the other
HCAHPS components, we found that the patient and healthcare staff relationship is also moderately
correlated with pain relief (r > 0.58). The current policies have not yet shown any significant
improvement in patient pain satisfaction from 5 years ago. This study provides the evidence needed
for hospitals to make pain care a priority in ultimately having patient satisfaction throughout the
duration of their hospitalization.
A130
EFFECT OF HUKO POINT ICE MASSAGE ON PAIN DEGREE DURING ARTERIOVENOUS
FISTULA PUNCTURE IN HEMODIALYSIS PATIENTS
F. Nasiri Ziba, F. Soltanpoor, N. Mohammadi
Medical Surgical Department, Tehran University of Medical Sciences, Medical School, Tehran, Iran
Background: Pain is described as the fifth vital sign and inadequate pain management is linked to
numerous immediate and long - term negative outcomes. Vein puncture is one of the most painful
medical procedures and one of the most frequently performed ones non-pharmacological
interventions can be implemented independently by nurses. The purpose of this study was to evaluate
the effect of ice huko point massage on pain during arterio-venous fistula puncture.
Intervention: In randomize control trial study, ninety (90) patients in hemodialysis wards were
randomly assigned to either the huko point ice stimulation(n=30) and two control group (n=30) who
were undergoing hemodialysis by using AVF. We were randomly assigned to experimental and
control groups using a randomization table. The experimental group received ice massage on hoku
point, the first control group received massaged on wrist and second control group received massage
on huko point.
Outcome: At first day without intervention ,arterio-venous fistula puncture pain was measured by
visual analogue scale. on second day after 10 minutes intervention in 3 groups pain degree was
measured. There were significant statistical difference in 3 groups after interventions( p=./001)
Conclusion: These findings showed that huko point ice massage was effective and safe for
decreasing on pain degree during arterio-venous fistula puncture in hemodialysis patients.
A131
PULMONARY HYPERTENSION IN A PARTURIENT MANAGED WITH AN INTERMITTENT
SPINAL INFUSION FOR CESAREAN SECTION
D. Nguyen, C. Martinello, J. Kwan, A. Singal, A. Van, E. Hurwitz
Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX, USA
Pulmonary hypertension during pregnancy is a relatively rare condition that can affect many patients
differently during the parturient course. In our institution, the Anesthesiology service was consulted in
advance on a term pregnant patient with severe pulmonary hypertension for cesarean section. Before
performing any anesthetic interventions, we performed a literature review to determine the
epidemiology and the most optimal treatment plan for pulmonary hypertension during pregnancy. Our
patient´s treatment plan for the cesarean section was with an epidural catheter for surgical
anesthesia, but an inadvertent dural puncture by another Anesthesiologist occurred during epidural
placement. Subsequently, the patient was managed with an intermittent intrathecal infusion of
hyperbaric 0.75% bupivacaine and preservative-free morphine without any complications. In our
literature review, the terms "pulmonary hypertension" alone and with the keywords “pregnancy”,
“pregnant”, and “parturient” were used as the search subject. The following medical search databases
were utilized: Pubmed, Cochrane Library, United States National Library of Medicine, MDConsult,
Medscape, Google and Google Scholar, Merck Manual, Web Directory of Medical Education, and
UpToDate. After examination of the 57 collected papers and reports, 44 publications were found that
the abstract´s authors felt were of clinical relevance towards our case patient. Pulmonary
hypertension (in parturients and non-parturients) has been classified by the Venice Clinical
Classification system updated by the Dana Point Classification system into five major clinical
categories of pulmonary hypertension as determined by its etiology. Based upon the literature review,
the parturient patient with pulmonary hypertension often becomes symptomatic during the end of the
second trimester or during the beginning of the third trimester. However, the most most critical time for
these patients is immediately postpartum and up to one month after delivery. Due to the relatively rare
number of cases of diagnosed pulmonary hypertension during pregnancy, much of the literature is
based upon case reports, anecdotal data, and retrospective reviews. Randomized clinical trials are
not available to formulate an absolute recommended treatment algorithm. Pharmacologic treatment
options include prostaglandins, inotropic agents including phosphodiesterase-3 inhibitors and
dobutamine, vasopressors such as norepinephrine or phenylephrine, sildenafil, and inhaled nitric
oxide. Specific anesthetic considerations include attention to arterial oxygen saturation, cardiac
rhythm, and blood pressure. A central venous catheter and arterial catheter for invasive blood
pressure monitoring are routinely recommended. Pulmonary artery catheters are generally considered
on a case-by-case scenario, and the risks of the catheter and placement must be weighed against the
diagnostic benefits. When vaginal delivery is chosen, low dose epidural anesthesia should be placed
early in labor as it often decreases the adverse hemodynamic effects of labor. Epidural anesthesia
with slow titration to the desired effect seems to be the safer technique in case a cesarean delivery is
indicated, although our patient was treated with an intrathecal infusion without any adverse effects.
Pulmonary hypertension during pregnancy is a rare condition, and treatment often needs to be
individualized for each patient. Further research on parturients with pulmonary hypertension will likely
be beneficial in determining optimal treatment plans for this patient population.
A132
CONVERSION OF CHRONIC PAIN PATIENTS FROM HIGH DOSE FULL-OPIATE AGONISTS TO
SUBLINGUAL BUPRENORPHINE
1
2
1
1
J. Daitch , D. Daitch , D. Novinson , C. Mitnick , J. Pergolizzi
1
3
2
Advanced Pain Management Specialists, Fort Myers, FL, Thomas Jefferson University,
3
Philadelphia, PA, Johns Hopkins University, Baltimore, MD, USA
Introduction: Buprenorphine SL is unique among the opiate class of analgesics; this compound has
a high affinity for the µ-receptor, yet only partially activates it. Thus, buprenorphine SL can provide
analgesia while minimizing opiate side effects. Sublingual buprenorphine (buprenorphine SL) is a
preparation that has been used to treat opiate dependence. Nevertheless, the Drug Enforcement
Administration (DEA) has acknowledged the legality of an off-label to use treat pain with the
sublingual buprenorphine preparation (1). Many patients on high doses of opiate medication develop
opiate-induced hyperalgesia (2), which may limit efficacy. The purpose of this study is to determine
the effectiveness of converting patients from high doses of full agonist opiate medication to sublingual
buprenorphine, as well as to identify patient groups that are most likely to benefit from this therapy.
Materials and methods: Retrospective data from clinical records was taken from 35 de-identified
chronic pain patients (22 male and 13 female, age 24-66) who had previously been treated with highdose opiate-agonist drugs and were converted to buprenorphine SL in tablet form during the study.
High dose opiates were defined as over 200 mg morphine equivalent per day. Patients ranged from
morphine equivalents of 200mg to 1370mg. Data collected from patient profiles included age, sex,
diagnosis, medication history, pre-induction opioid intake, and pre-induction Clinical Opiate
Withdrawal Score (COWS). Numerical pain levels and Quality of Life scores were recorded before
and after conversion to buprenorphine SL.
Results:
[Pre-, Post-Conversion Scores by Initial Pain]
After continuation of buprenorphine SL therapy for more than two months, the mean pain scores in all
groups decreased by 3.7 points (p< 0.001) which was more than a 50% decrease in numerical pain
score from 7.2 to 3.5.
[Pre-, Post-Conversion Scores by Morphine Equivs.]
The mean daily pre-induction morphine equivalent dose of opiate was 550 mg. Patients with morphine
equivalents of 200-400mg decreased the most in pain score with a 62% decrease in pain. Patients
taking over 400mg morphine equivalents decreased 43% in pain scores. This may be related to a
decrease in opioid-induced hyperalgesia. In addition, all patients who were on high dose opiate
medication, regardless of their initial pain score, responded with improved analgesia after conversion
to buprenorphine. The average dose of buprenorphine SL was 28.11mg +/- 5.94. Patient Quality of
Life (QOL) scale was not significantly affected by buprenorphine SL therapy (p=0.087).
Discussion: Patients converting from high dose full-opiate agonists from 200mg to 1370 mg of
morphine equivalents who continued buprenorphine SL therapy for more than 60 days reported a
significant decrease in pain of >50% from 7.2 to 3.5 (3.7 points). This cannot be completely explained
as elimination of opiate-induced hyperalgesia, since even patients at low levels of pain (1-7) on high
doses of opiates also experienced significant decreases in pain.
References:
1. Heit H, Covington E, Good P. Dear DEA. Pain Med 2004;5:303-308.
2. Angst M, Clark J. Opioid-induced hyperalgesia: A qualitative systematic review. Anesthesiology
2006; 104:570-587.
Funding: None
A133
ULTRASOUND-GUIDED PARAVERTEBRAL CATHETERS VERSUS INCISIONAL LOCAL
ANESETHETIC INFUSION AND PATIENT CONTROLLED ANALGESIA FOR POST-OPERATIVE
PAIN CONTROL IN SINGLE LUNG TRANSPLANT PATIENTS: A RETROSPECTIVE COHORT
1
1
2
K. Ohden , R. Kelly , J. D'Cunha , J. Hutchins
1
1
2
University of Minnesota, Minneapolis, MN, University of Pittsburgh Medical Center, Pittsburgh, PA,
USA
Introduction: Recent studies have shown that paravertebral catheters provide superior pain control
over incisional local anesthetic pumps with narcotic PCAs and possibly associated with less adverse
1,2
events.
Prior to November 2011 at the University of Minnesota, single lung transplantation patients'
post-operative incisional pain was treated with an incisional local anesthetic infusion with a narcotic
PCA. However, after November 2011, paravertebral catheters were the treatment of choice for lung
transplant patients´ postoperative pain. We sought to determine whether a paravertebral catheter and
opioid PCA provided improved pain control with decreased narcotic use in patients undergoing lung
transplantation when compared to those who had an incisional local anesthetic infusion with opioid
PCA.
Methods: This was a retrospective cohort chart review of 16 patients, 8 patients who had a
paravertebral catheter and 8 patients who had an incisional local anesthetic pump and opioid PCA for
a single lung transplant from January 2011 to September 2012. Narcotics were normalized to fentanyl
equivalents and pain scores were obtained by the bedside nurse, anesthesia resident, or acute pain
nurse clinician.
Results: There was no significant difference in baseline characteristics between the two groups.
Those with paravertebral catheter had significantly less pain at rest when compared to local
anesthetic incisional pumps on catheter day 1, 3, and 5 with a trend toward decreased pain scores on
2, 4, 6, and 7. Those with a paravertebral catheter had significantly less pain scores with movement
compared to local anesthetic infusion on catheter day 2, 4, and 6 with trend toward decreased pain
scores on days 1, 3, 5, and 7. There was a significantly decreased amount of narcotic used in those
patients with paravertebral catheter on catheter day 3 and 4 with trend towards decreased narcotics
on days 1, 2, 5, 6, and 7. The total narcotics used was 1339 mcg +/- 134 mcg of Fentanyl in those
with paravertebral vs 2525 mcg +/- 638 mcg in those with an incisional local anesthetic infusion p =
0.0904. There were no significant differences in complications or side effects between the two groups.
Discussion: This study suggests that paravertebral catheter infusion offers improved pain control and
decreased narcotic use when compared to incisional local anesthetic infusion.
References:
1. Kotze, A., A. Scally, and S. Howell. "Efficacy and Safety of Different Techniques of Paravertebral
Block for Analgesia after Thoracotomy: A Systematic Review and Metaregression." British Journal of
Anaesthesia 103.5 (2009): 626-36
2. Marret E, Vigneau A, Salengro A, Noirot A, Bonnet F. Effectiveness of analgesic techniques after
breast surgery: A meta-analysis. Ann Fr Anesth Reanim 2006; 25:947-54.
Disclosure: J. Hutchins is on the speaker´s bureau for I-Flow.
A134
ASSESSING THE NEED FOR POSTOPERATIVE SCIATIC NERVE BLOCK FOR PAIN RELIEF
AFTER NON-HAMSTRING ACL RECONSTRUCTION
K.M. Hibbard, S.L. Orebaugh, B.A. Williams, M.L. Kentor
Anesthesiology, University of Pittsburgh, Pittsburgh, PA, USA
Introduction: Postoperative analgesia for patients undergoing ACL reconstruction commonly involves
a femoral nerve block (1). However, sciatic block is also occasionally required as well when
dermatomes, myotomes, and/or osteotomes of this nerve may be affected by incision or drilling (2).
We evaluated adequacy of postoperative pain relief in patients undergoing ACL reconstruction with
preoperative femoral block and general anesthesia with "multimodal" analgesia. Specifically, we
determined the frequency sciatic nerve block was required as a supplemental block in PACU for pain
relief.
Methods: Forty-Six ASA 1 and 2 patients receiving allograft or patellar tendon autograft ACL were
enrolled. Each received multimodal analgesia with preoperative femoral nerve block, acetaminophen
1000 mg PO, ketamine 25-50 mg IV, and hydromorphone 1-2mg IV. Pain scores were recorded in
PACU on arrival and at ten minute intervals. Patients whose pain scores remained greater than or
equal to 5/10 received a postoperative sciatic block.
Results: Patient demographics are reported in Table 1.
No Post-Op Sciatic
Post-Op Sciatic
37
9
28.05, (9.81)
27, (9.31)
78.38
77.78
27.61, (5.34)
25.8, (3.88)
Cadaver Allograft, n (%)
8, (21.66)
2, (22.22)
Patella Tendon Autograft, n (%)
29, (78.34)
7, (77.78)
n
Age, yr, (SD)
Male, %
BMI, (SD)
[Table 1: Patient Demographics]
Nine out of 46 (19.56%, CI 10 - 33%) patients required postoperative sciatic block based on the listed
criteria. Patients who received a sciatic block had a mean pain score of 6.7/10 after 10 minutes in the
PACU, while those who did not had a mean pain score of 4.4/10 (p=.0038). Patients that required a
postoperative sciatic block also received a higher dose of intraoperative hydromorphone 0.8 vs. 0.38
mg (p=.017). After sciatic block, pain scores decreased from a mean of 6.6 to 2.6.
No Post-Op Sciatic
Post-Op Sciatic
0.97, (1.21)
1.67, (1.66)
36.48, (16.24)
38.89, (13.18)
Intra-Op Dihydromorphone, mg,
(SD)
0.38, (0.41)
0.27, (0.48)
Pain Score, PACU Arrival, (SD)
3.39, (3.74)
5.72, (3.60)
Pain Score, 10 mins in PACU,
(SD)
1.08, (3.25)
6.78, (2.17)
PACU; Dihydromorphone, mg,
(SD)
0.7, (0.62)
0.77, (0.36)
Pre-Op Pain Score, (SD)
Intra-Op Ketamine, mg, (SD)
[Table 2: Patient Data]
Conclusion: Femoral nerve block plus multimodal analgesia provided adequate pain relief in 37 out
of 46 of patients receiving cadaver allograft or patellar tendon autograft ACL reconstruction.
References:
1. Williams BA, Kentor ML, Vogt MT, Irrgang JJ, Bottegal MT, West RV, Harner CD, Fu FH, Williams
JP. Reduction of Verbal Pain Scores after Anterior Cruciate Ligament Reconstruction with 2-Day
Continuous Femoral Nerve Block. Anes 2006; 104:315-27.
2. Dauri M, Fabbi E, Mariani P, Faria S, Carpenedo R, Sidiropoulou T, Coniglione F, Silvi M, Sabato
A. Continuous femoral nerve block provides superior analgesia compared with continuous intraarticular and wound infusion after anterior cruciate ligament reconstruction. Reg Anesth Pain Med
2009; 34:95-99.
A135
ASSESSMENT OF A CHECKLIST-BASED EDUCATIONAL TOOL FOR ULTRASOUND-GUIDED
INTERSCALENE PERIPHERAL NERVE BLOCKADE
J. Resti, S. Orebaugh, Division of Acute Interventional Pain and Regional Anesthesia
Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
Introduction: Checklists have become an indispensable tool in ensuring patient safety in modern
medicine (1,2). In regional anesthesia, checklists have been demonstrated to improve management
decisions in simulated complications (3). We evaluated the adherence of residents to a previously
validated block checklist in clinical care during a regional anesthesia/ambulatory rotation, and
secondarily the contribution that this checklist made to attending evaluations of resident performance.
Materials and methods: A 34-point, task-specific checklist, adapted from other sources and
previously validated (4), was tailored for single-shot interscalene peripheral nerve block (Figure 1).
Over a 6 month period, senior and junior residents underwent a partial-task trainer simulation on the
first day of the regional anesthesia rotation with this checklist. During this exercise, residents
completed each task on the checklist, while providing an ultrasound-guided “block” to a gel model
adjacent to the neck of a mannequin. During the rotation, residents had access to the checklist, but
were not specifically directed to it. Later in the rotation, residents underwent evaluation for fidelity to
the checklist during an actual interscalene block.. Residents were also asked demographic questions
at this time (Figure 2). The mean number of correct checklist items were compared for senior and
junior residents utilizing a simple t-test.
[Figure 1. Task-specific Checklist]
[Figure 2. Questionnaire]
Results: Overall, 7 junior (PGY-2/3) and 5 senior (PGY-4) residents participated. The mean overall
number of items correct on the checklist was 32.5. This did not vary between the junior and senior
residents (Table 1). The most commonly missed items were tabulated (Table 2).
Junior Residents (n=7)
Senior Residents (n=5)
P value
Comfort Level of PNB
2.0
2.5
0.20
Number of USG PNBs
62.3
125.2
0.06
Number of USG ISBs
31.8
56.3
0.12
Number of Items
Completed Correctly
32.2
33.1
0.46
[Table 1]
Missed Item
Frequency
Turns on doppler function to scan for vessels at
injection site
5
Warns patient about discomfort on injection
5
Warns patient about nerve stimulation/motor
twitch
3
Prepares probe in sterile fashion
1
Checks that nerve stimulator is attached
1
Checks that block needle is appropriate and
primed
1
[Table 2]
Discussion: Residents exposed to a partial-task trainer to practice ultrasound-guided block while
enacting a checklist, displayed high fidelity to the checklist during actual block conduct later in the
rotation.
References:
1.
WHO
surgical
safety
checklist.
WorldAllianceforPatientSafety,
http://www.who.int/patientsafety/safesurgery/ss_checklist/en/index.html
2008.
2. Pronovost, P et al. An intervention to decrease catheter-related bloodstream infections in the ICU.
NEnglJMed. 2006;355:2725-32.
3. Neal JM, et al. ASRA checklist improved trainee performance during a simulated episode of local
anesthetic systemic toxicity. RegAnesthPainMed. 2012;37(1):8-18
4. Naik VN et al. An assessment tool for brachial-plexus regional anesthesia performance:
establishing construct validity and reliability. RegAnesthPainMed. 2007;32(1):41-5.
FUNDING: None.
A136
USE OF ULTRASOUND GUIDANCE FOR PERIPHERAL NERVE BLOCKADE AT A LARGE
ACADEMIC HEALTH CARE SYSTEM OVER A 6-YEAR PERIOD
S. Orebaugh, E. Conrad III, D. Taormina, D. Webb, J. Chelly
1
Department of Anesthesiology, Division of Acute Interventional Pain and Regional Anesthesia,
2
3
University of Pittsburgh, Department of Anesthesiology, Division of Acute Perioperative Pain and
4
Regional Anesthesia, University of Pittsburgh, Division of Acute Interventional Pain and Regional
Anesthesia, University of Pittsburgh, Pittsburgh, PA, USA
Introduction: Although the benefits associated with the use of ultrasound (US) to perform peripheral
nerve blocks remain the object of passionate debates, this approach has gained recognition. This
study was conducted to assess how the use of ultrasound evolved in the Division of Acute
Interventional Perioperative Pain and Regional Anesthesia (DAIPPRA) over a period of 6 years.
Method: DAIPPRA of the Department of Anesthesiology at the University of Pittsburgh performs
peripheral nerve blocks as part of acute postoperative pain management at 13 different UPMC
hospitals, including 4 ambulatory centers and 2 trauma hospitals, a pediatric hospital, University and
Community Hospitals. Using our IRB approved registry, the overall number of blocks performed at
each center was established over a six year period, including the % of blocks performed with US, to
demonstrate the evolving use of ultrasound guidance.
Results: Our data indicate that a 10 fold increase in the use of US occurred between 2007 and 2010.
This was the result of an increase in the use of ultrasound at each site, especially for lower extremity
and paravertebral blocks. In addition, US was utilized more frequently at ambulatory centers, where
mostly single and superficial blocks are performed, vs. inpatient facilities (90% vs. 48%). Table 1
presents the total number of blocks (blocks) and the relative frequency of the use of ultrasound (%),
for the Division (Overall) and per each reported site in 2007, 2010, and 2012.
Discussion: Ultrasound guided techniques have impacted the performance of peripheral nerve
blockade in many ways in the past decade (1). US allows visualization of the target nerves, and
facilitates the performance of certain blocks including supraclavicular, and transversus abdominis
plane blocks (2,3). Although it is clear that US guidance techniques are increasingly used in our
institution, the use of neurostimulation alone or in combination with US continues to be a valuable
alternative, especially for deep lower extremity blocks.
Funding: No specific funding was utlized for this study.
References:
1. Abrahams MS. Br J Anaesth 2009;102:408.
2. McCartney CJ. Reg Anesth Pain Med 2010;35:S10.
3. Abrahams MS. Reg Anesth Pain Med 2010;35:S36.
Table 1. Total number of blocks (blocks) and the relative frequency of the use of ultrasound, overall
and per hospital in 2007, 2010, and 2012.
[Table 1]
A137
PERCEPTION VERSUS REALITY: THE INCREASING AMERICAN HABITUS AND ITS IMPACT
ON PERI-OPERATIVE MANAGEMENT
A.M. Oviedo, S.M. Moeschler, C.M. Duncan, H.M. Smith, S.L. Kopp
Anesthesiology, Mayo Clinic, Rochester, MN, USA
Introduction: Obesity, defined as a body mass index (BMI) greater than 30 kg /m2, has increased
1, 2
significantly over the past twenty years in the United States
. As a result the rate of total joint
3
replacements has steadily increased over time . For example, total knee arthroplasties (TKAs) are
being performed in younger individuals and these patients have more comorbidities including diabetes
4
mellitus, obesity, hypercholesterolemia, hypertension, and pulmonary disease .
The primary aim of this study was to determine the demographic trends of patients undergoing
primary TKA during three different time periods: 1989, 1999 and 2009 at our institution and to
determine if it mirrors the changing demographics within the United States.
Methods: All adult patients that have undergone unilateral primary TKA during the calendar years of
1989, 1999 and 2009 were identified via the Mayo Clinic Total Joint Registry database. Two hundred
patients were randomly selected for each time period. A retrospective chart review of patient
demographics, comorbidities, perioperative practice and postoperative outcomes was performed. We
also studied the perception of experienced anesthesia providers regarding changes, or lack thereof, in
patient demographics and perioperative care via a web-based survey.
Results: During the three study periods a total of 590 patients were included for the analysis. Two
hundred patients from 1989; one hundred and ninety-three patients from 1999 and one hundred and
ninety-seven patients from 2009. A statistically significant increase in BMI was observed overtime in
patients undergoing primary TKA (average BMI: 29.01 in 1989; 31.32 in 1999 and 32.28 in 2009 (p <
0.001)). There was an increase in the number of patients with recognized preexisting comorbidities
such as hypertension, diabetes and obstructive sleep apnea. Despite the increase in patient
comorbidities, the number of postoperative complications decreased and postoperative disposition
(general medicine ward vs. ICU) did not change significantly.
The administration of exclusively general anesthesia declined. On the other hand, combined general
and regional anesthesia increased significantly.
Our survey received 76 % response rate. The majority of anesthesia providers perceive that BMI has
increased (average time in practice: 11 years) simultaneously with the number of comorbidities. This
trend in body habitus and rise in comorbidities leads the majority of the practitioners to modify their
perioperative anesthesia care.
Discussion: The number of obese patients with comorbidities presenting for TKA at our institution is
growing. Despite the fact that we are taking care of more complicated patients, a reduction in
postoperative complications was detected. This could be explained by anesthesiology practice
modifications including the increased implementation of regional anesthesia protocols, utilization of
non-narcotic analgesics and short acting medications.
References:
1. CDC. U.S. Obesity trends. November 24, 2009.
2. CDC. Available from: http://www.cdc.gov/nchs/nhanes/about_nhanes.htm
3. Kurtz, S., et al., Prevalence of primary and revision total hip and knee arthroplasty in the United
States from 1990 through 2002. J Bone Joint Surg Am, 2005. 87(7): p. 1487-97.
4. Memtsoudis, S.G., et al., Trends in demographics, comorbidity profiles, in-hospital complications
and mortality associated with primary knee arthroplasty. J Arthroplasty, 2009. 24(4): p. 518-27.
A138
A SURVEY OF KNOWLEDGE RELATING TO THE CAUSES, SIGNS AND TREATMENT OF
LOCAL ANAESTHETIC TOXICITY (LAST)
S. Patel, S. West, D. Kamming
1
2
University College Hospital, Anaesthetics, UCLH, London, UK
Introduction: Local anaesthetics are commonly used within the operating theatre suite to provide
intra and post operative analgesia. This may be via a number of routes including epidural, peripheral
nerve block and subcutaneous infiltration.
1
Local anaesthetic toxicity (LAST) is rare, with an incidence of 0.08 per 1000 quoted by Sites , but
potentially fatal. Avoidance of LAST requires knowledge of safe maximum doses of drugs, recognition
and of appropriate treatment. The use of lipid emulsion to treat LAST has been understood for many
3
years, and more recently been incorporated into several guidelines including those from the AAGBI
2
in the U.K. and ASRA in North America . Despite the increased availability of lipid emulsion in the U.K
over the last ten years, knowledge of its use is often variable.
We sought to assess the level of understanding of local anaesthetic doses and the effective
management of LAST within a busy University Hospital anaesthetic department.
Methods: A confidential questionnaire was distributed amongst both trainee anaesthetists and
consultant anaesthetists over a one-week period within the anaesthetic department.
Questions assessed knowledge of maximum local anaesthetic doses, signs and symptoms of local
anaesthetic toxicity, the awareness of guidelines used to treat LAST and the dosages and availability
of Intralipid (lipid emulsion therapy).
Results: 18 anaesthetic trainees and 20 anaesthetic consultants participated in the questionnaire.
82% correctly identified the correct maximum safe dose of both lignocaine and bupivacaine , although
when asked only 61% were able to translate this to an appropriate volume of 2% lignocaine.
100% of anaesthetists correctly identified both the neurological and cardiac signs of LA toxicity.
100% were aware of the availability of guidelines and the use of Intralipid to treat LAST.
Only 12%, however, were able to state the loading , maintenance and maximum dose of Intralipid and
only 40% correctly identified where it was kept.
Conclusion: Those using local anaesthetic should know the maximum safe dosages to avoid LAST
and how to manage LAST accordingly.
This group had a good understanding of maximum safe doses of local anaesthetics, however failings
were demonstrated when asked to translate this into a clinical volume for use.
The ability to recognise LAST was well demonstrated by the knowledge of signs and symptoms
relating to LAST.
The awareness of guidelines and the use of Intralipid to treat LAST was evident but there was still a
lack of knowledge on how to use Intralipid appropriately and where to find it.
Further to these results we propose an intervention of training in the use of Intralipid and a
subsequent re-audit of knowledge.
References:
1. Sites, Brian Daniel et al. Incidence of Local Anesthetic Systemic Toxicity and Postoperative
Neurologic Symptoms Associated With 12,668 Ultrasound-Guided Nerve Blocks: An Analysis From a
Prospective Clinical Registry. RAPM 2012; 37(5) 478-482
2. Management of Severe Local Anaesthetic Toxicity 2 ,
Association of Great Britain and Ireland, published December 2010.
3. Neal JM et al American Society of Regional Anesthesia and Pain Medicine checklist for managing
local anesthetic systemic toxicity: RAPM 2012 37(1)
A139
PREOPERATIVE THORACIC PARAVERTEBRAL BLOCKS ARE ASSOCIATED WITH LESS
INTRAOPERATIVE LONG ACTING IV OPIOID USE IN PATIENTS UNDERGOING BREAST
SURGERY
R. Pathak, S. Lien, S. Coopey, M. Specht, K. Fleischmann
1
2
Department of Anesthesia, Critical Care, and Pain Medicine, Department of Surgery, Massachusetts
General Hospital, Harvard Medical School, Boston, MA, USA
Introduction: Preoperative thoracic paravertebral blocks (TPVB) in patients undergoing breast
surgery have been shown to reduce postoperative pain, lower opioid requirements on the first
postoperative day, decrease postoperative nausea and vomiting, and decrease length of stay.
However, no prior studies have shown a significant decrease in the amount of long acting IV opioids
used intraoperatively. We report our institutional experience with the use of TPVB in patients
undergoing unilateral or bilateral mastectomy with immediate reconstruction (tissue expander or
implant placement).
Materials and methods: With Institutional Review Board approval, 160 patients were retrospectively
identified who underwent preoperative TPVB prior to mastectomy with immediate reconstruction at a
single institution in 2012. This group was compared to a similar group of 126 patients who underwent
mastectomy with immediate reconstruction without the use of TPVB in 2008. The doses of IV opioids
used intraoperatively were compared between the two groups.
Results: The total dose of long acting IV opioids (hydromorphone) given intraoperatively to the group
that received TPVB (0.97mg, 95% CI: 0.89-1.07) was significantly less than that given to the group
that did not receive TPVB (1.71mg, 95% CI: 1.56-1.85) (p< 0.0001). The amount of short acting IV
opioids (fentanyl) was not significantly different between the two groups (p=0.11).
Discussion: We conclude that preoperative TPVB significantly decreased the amount of long acting
IV opioid used intraoperatively. This decrease in opioid requirement may contribute to the lower rate
of PONV, faster transition time to oral opioids, and shorter length of stay seen in patients who
undergo preoperative TPVB, as previously shown by our regional group.
[Mean Amount of Hydromorphone (mg) Administered ]
TPVB Group (n=160)
Non- block Group
(n=126)
p-value
Hydromorphone(mg)
0.97 (95% CI: 0.891.07)
1.71 (95% CI: 1.561.85)
P < 0.0001
Fentanyl (mcg)
189.7 (95% CI: 173.25206.1)
169.02 (95% CI: 149.55P = 0.11
188.48)
[Comparison of TPVB Group to Non-Block Group]
References: Use of Preoperative Paravertebral Block Decreases Length of Stay in Patients
Undergoing Mastectomy Plus Immediate Reconstruction. Coopey SB, Specht MC, Warren L, Smith
BL, Winograd JM, Fleischmann K.Ann Surg Oncol. 2012 Oct 14.
General anaesthesia versus thoracic paravertebral block for breast surgery: a meta-analysis. Tahiri Y,
Tran de QH, Bouteaud J, Xu L, Lalonde D, Luc M, Nikolis A.
J Plast Reconstr Aesthet Surg. 2011 Oct;64(10):1261-9.
Prospective randomized trial of paravertebral block for patients undergoing breast cancer surgery.
Boughey JC, Goravanchi F, Parris RN, Kee SS, Kowalski AM, Frenzel JC, Bedrosian I, MericBernstam F, Hunt KK, Ames FC, Kuerer HM, Lucci A.
Am J Surg. 2009 Nov;198(5):720-5
Thoracic paravertebral block for breast surgery. Klein SM, Bergh A, Steele SM, Georgiade GS,
Greengrass RA. Anesth Analg. 2000 Jun;90(6):1402-5.
Single-injection paravertebral block compared to general anaesthesia in breast surgery. Pusch F,
Freitag H, Weinstabl C, Obwegeser R, Huber E, Wildling E. Acta Anaesthesiol Scand. 1999
Aug;43(7):770-4.
Funding/disclosures: none
A140
THE SPREAD OF LOCAL ANESTHETIC SOLUTION WITH BLOCKADE OF THE SCIATIC NERVE
WITH THE USE OF ULTRASOUND GUIDANCE
V. Piacherski, A. Marachkou, Z. Kokhan, A. Brukhnov
Health Care Institution «Mogilev Regional Hospital», Mogilev, Belarus
Aim of the work: To study the features of local anesthetic solution spreading during sciatic nerve
block, in dependence of the injected anesthetic solution volume.
Material and methods: We have analyzed the results of 79 cases of sciatic nerve block in
combination with femoral nerve block, in 79 patients in period 6 Jun 2009 - 1 Jul 2010, performed in
Mogilev Regional Hospital. The age of patients was 42.3±13.7 years. Sexes distribution was: 45 male
and 65 female patients. Sampling was carried out by a solid.
For providing the intraoperational anesthesia, all blocks were performed by lidocaine solution of
different concentrations, of the volume 25; 20; 15; 12.5; 10; 7.5; 6.5; 5; 4.5 ml, with addition of
adrenalin (1:200 000). For verifying the position of the needle and sciatic nerve, ultrasonic
visualization in combination with peripheral nerves electric stimulator were applied. In this procedure,
after obtaining the sonographic signs of sciatic nerve at ultrasonic apparatus screen, the injection
needle was approached to the nerve under ultrasonic control, till the appearance of muscle
contractions of the appropriate muscle group. The frequency of nerve stimulation was 1-2 Hz; the
electric stimulator generated impulses of direct current with the strength 0.1-1.0 mA, voltage 1-10 V
and impulse length 0.1 msec.
After the block performing, the second anesthesiologist, who did not know about the amount of
injected local anesthetic solution, independently measured cross-section area of sciatic nerve (S1)
and total cross-section area of sciatic nerve together with the ring of local anesthetic around the nerve
(S2). These measurements were done by means of ultrasonic apparatus software. The cross-section
area of the ring (S), corresponding to local anesthetic, was defined as the difference between S2 and
S1. Taking into account such character of spreading, to determine the length of anesthetic passing
along the nerve, we applied the formula QUOTE , where L - the length of local anesthetic spreading
2
(cm), V - the volume of injected local anesthetic (ml), S - cross-section area of local anesthetic (cm ).
Results: The anesthetic agent solution spreads along sciatic nerve in proximal and distal direction,
forming a kind of cylinder. The minimum volume of the local anesthetic, which covers sciatic nerve in
the whole, is 5 ml. Minimum volume of local anesthetic solution, which wraps totally around sciatic
nerve in adult patients, is 5 ml. The full spreading of the local anesthetic around sciatic nerve was not
observed, if 4.5 ml of the solution were used.
V, ml
L, sm
S, sm2
4,5 (n=5)
8,49(6,92;10,97)
0,53(0,41;0,65)
5(n=9)
11,36(10,41;13,51) 0,44(0,37;0,48)
6,5(n=5)
10,83(10,79;1085) 0,61(0,60;0,62)
7,5(n=5)
13,30(13,20;13,50) 0,69(0,68;0,70)
10(n=12)
13,52(12,73;15,03) 0,74(0,66;0,78)
12,5(n=6)
12,82(11,90;14,08) 0,78(0,71;0,84)
15(n=12)
18,43(14,85;20,98) 0,81(0,71;1,01)
20(n=9)
20,40(18,18;20,23) 0,98(0,96;1,10)
25(n=16)
21,20(20,16;23,29) 1,18(1,07;1,24)
[Table 1]
A141
DESCRIPTION OF THE SONOANATOMY OF THE SUPRASCAPULAR AND AXILLARY NERVES
D. Price, N. Kershaw, L. Zhou
North Shore Hospital, Auckland, New Zealand
Introduction: Combined suprascapular and axillary nerve blockade (CSANB) has been shown to
provide comparable analgesia to interscalene block following arthroscopic shoulder surgery, with
significantly less side effects (1). CSANB was originally described using anatomical landmarks and a
nerve stimulator (2). However, ultrasound (US) guidance has recently become the preferred technique
for peripheral nerve blockade. The aim of this descriptive study is to determine how effectively the
suprascapular nerve (SN )and the axillary nerve (AN), which are both small and deep to large
muscles, and adjacent anatomical structures can be imaged with US.
Method: US imaging was performed bilaterally on 50 seated volunteers. Images were generated at 3
separate points along the course of each nerve, in both short axis (SAX) and long axis (LAX),
resulting in a total of 1200 separate US images. Each structure was assigned an image rating score
of 0 (not visible), 1 (poor), 2 (reasonable) or 3 (excellent).
Results: The estmated nerve depth for AN was greatest in the quadriteral space, and for SN, the
greater scapular notch. AN was shallowest on the lateral surface of humerus, and SN, the
suprascapular notch. Bone was the most reliably imaged structure in all views, while both arteries was
seen more reliably than either nerve (Table 1). The best image of the SN and artery is the in the
supraspinous fossa, in LAX on the right and SAX on the left. The best image of the AN and circumflex
artery is the posterior surface of the humerus in LAX on both sides.
Conclusion: Images of anatomical structures relevant to the performance of US-guided CSANB were
able to be located, and their image quality rated, in this purely descriptive study.
References:
1. Price D, Abeysekera A, Chaddock M. A randomised comparison of combined suprascapular and
axillary (circumflex) nerve block with interscalene block for postoperative analgesia following
arthroscopic shoulder surgery. Anaesth Intensive Care 2012. 40,1 183-184
2. Price DJ. The shoulder block: a new alternative to interscalene brachial plexus blockade for the
control of postoperative shoulder pain. Anaesthesia Intensive Care 2007;35:575-581
Funding: There are no funding disclosures to make for this study.
Personal conflicts of interest disclosure: There are no conflict of interest disclosures to make for
this study.
A142
ARTHROPLASTY CARE REDESIGN: IMPACT OF SPINAL DOSING ON POST ANESTHESIA
RECOVERY UNIT LENGTH OF STAY AFTER TOTAL KNEE ARTHROPLASTY
S. Pritzlaff, E.A. Jacob, K. McCarty, M. Rozanski, R. Dorman, O.V. Evgenov, K. Fleischmann, A.
Freiberg, M. Gargarian, W. Levine, J. Lewis, V. Modest, P. Stefanovich, S. Vassallo, J. Wang, L.
Warren, L. Wollman-Kliman, J. Rathmell, R. Peloquin, MGH Arthroplasty Care Redesign Team
1
2
3
Anesthesia, Critical Care, and Pain Medicine, Physical Therapy Services, Orthopedic Surgery,
Massachusetts General Hospital, Boston, MA, USA
Introduction: The MGH Arthroplasty Care Redesign Team was charged with evaluating our
arthroplasty care with the aim of reducing cost while maintaining or improving quality. An initially
identified limitation to early ambulation and thus overall length of hospitalization was extended length
of stay in the PACU (PACU LOS), particularly among patients receiving spinal anesthesia (SA) for
1
Total Knee Arthroplasty (TKA). This led to a systematic examination of TKA SA dosing and
subsequent efforts to reduce those doses. Here, we retrospectively analyzed the influence of SA
bupivacaine doses on PACU LOS after TKA in comparison with use of general anesthesia (GA).
Methods: Using our perioperative electronic health record, we retrospectively reviewed all adult
patients who underwent TKA at MGH from January 2010 - September 2012. Beginning in January
2012, anesthesia practitioners were encouraged to reduce isobaric bupivacaine doses used for TKA.
TKA performed during January 2010 - September 2011 were assigned to Period 1; TKA performed
during January - September 2012 were assigned to Period 2. The primary endpoint was PACU LOS,
defined as surgical close to medically ready to leave the PACU. All data are shown as mean ±
standard deviation and were analyzed using two-tailed t-tests with significance set at p< 0.05.
Results: 955 TKA were performed during Period 1: 351 under GA and 604 under SA. 464 TKA were
performed during Period 2: 210 under GA and 254 under SA. The SA dose of 0.5% bupivacaine
decreased from 17.3±2 mg in Period 1 to 13.9±2mg in Period 2 (p< 0.001).
[Table 1]
PACU LOS in those receiving SA decreased from 265±109min during Period 1 to 217±91min during
Period 2 (p< 0.001). PACU LOS decreased in those receiving GA from 211±94min during Period 1 to
199±93min during Period 2, though not significantly (p = 0.08). For all TKA patients, PACU LOS
decreased from 245±107min during Period 1 to 209±92min during Period 2 (p< 0.001).
[Figure 1]
The overall reduction in PACU LOS during Period 2 was 16,704 minutes.
Discussion: Extended PACU LOS delays physical therapy and mobilization following TKA.
Examination of our anesthetic outcomes led to a significant reduction in SA doses and an associated
reduction in PACU LOS, suggesting enormous implications for PACU efficiency and cost containment.
Further study is needed to establish optimal SA dosing that assures sufficient anesthesia duration
while minimizing recovery time.
References: 1. McCarty et al., “Impact of General versus Spinal Anesthesia on Post-Anesthesia Care
Unit Recovery Time Following Total Hip and Knee” ASA Conference Abstract October 2012.
Funding: MGH CQS - Clinical Innovation Award
COIs: none
A143
PAIN, ANXIETY AND DEPRESSION FOLLOWING TRAUMATIC MUSCULOSKELETAL INJURY
B.N. Rosenbloom, L. Bosco, L. Haslam, H. Kreder, J. Katz, C.J. McCartney
1
2
3
Institute of Medical Science, University of Toronto, Lawrence S. Bloomberg Faculty of Nursing,
4
5
University of Toronto, Orthopedics, Sunnybrook Health Sciences Centre, Department of Psychology,
6
York University, Department of Anesthesia, Sunnybrook Health Sciences Centre, Toronto, ON,
Canada
Introduction: Traumatic injury is the fourth leading cause of death. The most common injuries from
trauma are orthopedic, which often require surgical interventions. Many patients go on to have
1
persistent pain and psychological distress after trauma ; however, we do not know the incidence of
these outcomes following traumatic musculoskeletal injury (TMSI). Thus the aims of this ongoing pilot
study are (1) to determine the incidence of acute pain while in hospital and persistent pain at 3months following TMSI, and (2) to examine the associations between pain, anxiety, and depressive
symptoms during hospitalization.
Methods: This study was approved by Sunnybrook HSC IRB. We used a prospective, longitudinal
design to follow participants up to 3 months after injury. Inclusion criteria were: >17 years, sustained a
TMSI; trauma admission and length of hospital stay (LOS) ≥2 days. Participants with Glasgow Coma
Scale motor ≤ 5, spinal cord damage, burns, or self-injury, or who had a mechanical fall were
excluded. Participants were followed during hospitalization (T1) and at 3-months (T2) post TMSI.
Participants provided demographic information, as well as reliable and valid measures of pain,
function, disability and psychological distress. Statistical analyses included descriptive analyses,
paired t-tests, and correlations.
Results: The initial sample comprised 53 participants (67.9% male) with a mean age of 46.6 years
(SD=19.22). The average Injury Severity Score was 17.6 (SD=8.02) and length of stay was 14.5 days
(SD=20.12). 35% (n=19) of participants reported pre-injury conditions (e.g., asthma, diabetes, chronic
pain) and an overall health rating of 3.04 (SD=0.99, range 1-5) on a scale of 0- poor health to 5excellent health. Attrition rate was 46% with n= 34 completing the 3-month follow-up. Significant
differences were not found on demographic measures between those who completed the 3-month
follow-up and those who did not.
92.5% (n=49) and 85.0% (n=29) of participants reported pain while in hospital and at 3 months,
respectively. Pain scores (0-10 numeric rating scale) decreased significantly from T1 (Mean=4.7,
SD=1.86, Median=5, Range 0-10) to T2 [(Mean= 3.01; SD = 2.34, Median=2, Range 0-10); t(31) =
4.00, p=.000] as did pain disability [T1 (M = 6.80, SD = 2.44); T2 [(M = 3.46, SD = 2.73); t(30) = 6.24].
T1 pain intensity was significantly correlated with T1 anxiety (r =.470, p=.000), depression (r =.362,
p=.008), anxiety sensitivity (r =.281, p=.043), fear and anxiety related responses to pain (r =.370,
p=.007), self-efficacy in managing pain (r =-.319, p=.021) and posttraumatic stress symptoms (r
=.345, p=.012).
Discussion: The preliminary results indicate the high incidence of pain following TMSI and point to an
association between anxiety, depression, and pain during the in-hospital stay. With additional
participant recruitment into this ongoing study, and appropriate statistical power, we will identify the
risk and protective factors associated with the development of persistent pain 3-months after TMSI.
Funding disclosure: Nothing to disclose.
Reference:
1. Rosenbloom BN, Khan S, McCartney C, Katz J. Pain and Psychological Outcomes Following
Traumatic Musculoskeletal Injury. Journal of Pain Research. 2013;6:39-51.
A144
A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL TO EVALUATE THE
®
EFFICACY AND SAFETY OF THE SUFENTANIL NANOTAB PCA SYSTEM/15MCG FOR POSTOPERATIVE PAIN IN PATIENTS AFTER ABDOMINAL SURGERY
1
2
3
4
5
F.G. Ringold , H. Minkowitz , T.-J. Gan , K. Aqua , P.P. Palmer , M.A. Royal
1
5
2
Surgery, Surgical Associates of Mobile, Mobile, AL, Anesthesiology, Memorial Hermann Memorial
3
City Hospital Medical Center, Houston, TX, Anesthesiology, Duke University Medical Center,
4
Durham, NC, Obstetrics-Gynecology, Atlantic Clinical Research Collaborative, Boynton Beach, FL,
5
Clinical, AcelRx Pharmaceuticals, Inc., Redwood City, CA, USA
Introduction: The Sufentanil NanoTab PCA System (SNPS) is a novel preprogrammed noninvasive
product candidate in Phase 3 development that dispenses small (3 mm diameter) sufentanil 15 mcg
microtablets sublingually with a 20-minute lockout period. Sufentanil is an opioid approved as an IV
formulation for the induction and maintenance of anesthesia and for labor epidural use. It possesses a
high therapeutic index with minimal respiratory depressive effects relative to its analgesic effect in
animal studies, a low incidence of cardiac instability and minimal pharmacokinetic differences based
on age, liver or kidney function. While these attributes could be ideal in a post-operative opioid
analgesic, its rapid redistribution from plasma following IV administration and short duration of action
make it less than ideal for intravenous patient-controlled analgesia (IV PCA). IV PCA, particularly with
morphine, is commonly used for the management of moderate-to-severe post-operative pain.
However, its use is associated with limitations, including the use of low therapeutic index opioids, the
risk of pump programming errors and reduced patient mobility due to IV tethering.
Materials/Methods: This randomized, double blind, placebo-controlled Phase 3 study was performed
as one of two pivotal studies required for FDA approval of SNPS. The study objectives were to
compare the safety and efficacy of SNPS to placebo delivered via the SNPS device for the
management of moderate-to-severe post-operative pain after open abdominal surgery. Up to 180
post-operative inpatients (18 years and older) who were expected to require parenteral opioid
analgesia for at least 48 hours after surgery were to be randomized (120 patients in SNPS 15 mcg
group and 60 patients in placebo group) to ensure at least 159 total patients (106 in the SNPS group
and 53 in the placebo group), who received study drug and provide primary efficacy data (90% power)
for analysis. The primary efficacy variable was the time-weighted summed pain intensity difference
over the 48-hour study period (SPID-48) using an 11-point numerical rating scale. Key secondary
efficacy variables included pain intensity and pain relief scores (5-point categorical scale) over the
study period, patient global assessments of method of pain control (4-point categorical scale), patient
and nurse ease of care scores (using a validated Ease-of-Use questionnaire), and rescue medication
consumption. Safety assessments included spontaneous adverse reaction reports, vital signs,
medical history, physical examinations, oxygen saturation measurements, and concomitant
medication usage.
Results: The first patient in for the study occurred on March 6, 2012 and last patient out occurred on
January 12, 2013. A total of 214 patients were screened and 178 were randomized. There were a
total of 36 screen failures. At the time of this abstract submission, data analysis was in process. Full
data will be available at the time of the meeting and presented in the poster.
Conclusion: The Sufentanil NanoTab PCA System provides an attractive alternative to traditional IV
PCA analgesia, is easy for healthcare professionals to set-up and for patients to use. Upon
completion of the required Phase 3 studies, a new drug application will be submitted to FDA for
review.
A145
®
SUFENTANIL NANOTAB PCA SYSTEM: RESULTS FROM THREE HUMAN FACTORS STUDIES
P.P. Palmer, B.N. Dasu, M.A. Royal
1
2
Clinical, Engineering, AcelRx Pharmaceuticals, Inc., Redwood City, CA, USA
Introduction: Intravenous patient-controlled analgesia (IV PCA) is standard of care in many hospitals
for managing post-operative pain. It is often associated with limitations, including use of low
therapeutic index opioids, programming errors, reduced patient mobility and infiltrated IVs. The
®
Sufentanil NanoTab PCA System (SNPS) is a novel, non-invasive, preprogrammed approach to
patient-controlled sublingual analgesia currently in development that avoids the issues of medication
and programming errors which occur with IV PCA. Patients can utilize the System to deliver 15 mcg
sufentanil tablets sublingually with a 20-minute lockout between doses. Two randomized, controlled
Phase 2 studies, an open-label Phase 2 device functionality study, and a randomized Phase 3 noninferiority trial vs. IV PCA morphine have demonstrated that sublingual delivery of sufentanil is
efficacious and well tolerated in treating moderate-to-severe post-operative pain after major surgery.
Two, randomized, placebo-controlled Phase 3 trials are ongoing.
Materials/methods: Human factors (HF) studies are an important aspect of device development to
allow end-user feedback on system design features, functionality, and usability. Three SNPS HF
studies are discussed. Farm Design co-developed the test protocol and moderated the sessions.
During the training portion and post-test interview, the moderator and nurse sat at a table equipped
with system components, a box containing all System components and a copy of the instructions for
use (IFU) guide for the nurse to use during the review and practice session.
Results: HF Study 1 involved 19 nurse and central sterile/biomedical engineer participants without
prior System training to assess the IFU guide for comprehension. HF Study 2 involved 15 nurse
participants who were experienced in setting up PCA pumps. HF Study 3 included 15 nurses and 15
healthy adults (mean age 61.5 years) who simulated patient interactions in a study evaluating 15
nurse-”patient” pairs. Sessions were conducted over 7 days. All of these participants were from
Northern California and all “patient” participants were at least high school graduates and six had had
prior surgery. Of the 30 total nurse participants who were trained in system use in HF studies, onethird used reading glasses. Testing mimicked a “worst case” scenario in that participants only had one
chance to set up the SNPS before being evaluated on 10 separate tasks related to the system's
primary operating functions. After a short period of training, all nurses completed the 10 tasks with
little help and all patients completed 3 tasks with little help. No task rated lower than a 4.1 on a 5-point
categorical ease-of-use scale. Nearly all participants said that they would have no trouble using the
SNPS once they were used to it. Participants said that the user interface was so easy to follow that
they did not need to refer to the IFU.
Conclusion: Based on the results from these studies, it appears that the Sufentanil NanoTab PCA
System is an easy to use and relatively intuitive device. Additional HF studies are planned using
pharmacists, physicians and adults with hearing and visual impairment.
A146
®
SUFENTANIL NANOTAB PCA SYSTEM: MECHANICAL AND SOFTWARE DESIGN FEATURES
1,2
1
P.P. Palmer , B.N. Dasu , M.A. Royal
1
1
2
Clinical, AcelRx Pharmaceuticals, Inc., Redwood City, Anesthesiology, University of California, San
3
Francisco, San Francisco, Engineering, AcelRx Pharmaceuticals, Inc., Redwood City, CA, USA
Introduction: Intravenous patient-controlled analgesia (IV PCA) is commonly used to manage
postoperative pain. However, it is associated with limitations, including programming errors and
reduced patient mobility. Sufentanil is an opioid approved for IV and epidural administration. While it
possesses a high therapeutic index with minimal respiratory depressive effects relative to its analgesic
effect, high cardiac stability and minimal pharmacokinetic differences based on age, liver or kidney
function, its rapid redistribution from plasma following IV administration and short duration of action
make it less than ideal for IV PCA. The Sufentanil NanoTab PCA System is a novel preprogrammed
noninvasive product in Phase 3 development designed to deliver sublingual sufentanil 15 mcg
microtablets with a 20-minute lockout period.
Methods: Issues with IV PCA delivery of opioids were assessed and categorized. Design of the
Sufentanil NanoTab PCA System was focused on features to avoid or minimize these identified
issues. Four human factors and ease-of-use studies were conducted to optimize design functionality
and obtain user feedback on features and usability of the Sufentanil NanoTab PCA System. System
functionality and usability were then tested in 3 Phase 3 studies in hospitalized patients with
moderate-to-severe pain after major surgery.
Results: The device is comfortable when held and easy for patients to handle and operate. The
preprogrammed device (fixed dose and lockout interval) eliminates programming errors. A screen
provides easy to follow set-up steps for the nurse and bedside patient training. Tones and indicator
lights confirm successful dose administration to the patient. An accelerometer assists with proper
orientation of the device for sublingual dosing. A radiofrequency identification (RFID) tag worn by the
patient pairs the device to a unique patient to reduce the potential for proxy dosing. A steel cable
tether locks the device to the bedside or wheelchair to prevent diversion. The device tracks dose
attempts and successful deliveries to help assess patient proper use and understanding. All data can
be downloaded for reconciliation audits and for patient medical records. The device's battery is
designed to last up to 72h and is easily recharged between uses.
Conclusion: PCA pumps are commonly used to manage postoperative pain, however their use is
associated with limitations:




1
Risk of programming errors
2
Risk of analgesic gaps due to IV problems or pump malfunctions
Reduced patient mobility due to tethering to IV line and pole-mounted pump
3,4
Risk of proxy dosing by someone other than the patient
The Sufentanil NanoTab PCA System is designed to address these limitations:




Preprogrammed device eliminates programming errors which can occur with IV PCA
System screen prompts designed to facilitate proper setup and use
RFID tag and locking tether reduces the potential for proxy dosing and diversion
Sublingual route of delivery avoids IV-related complications
A147
CONTINUOUS REGIONAL ANALGESIA AFTER ORTHOPEDIC FOOT SURGERY: COMPARISON
OF COSTS AND STANDARDS OF CARE IN OUTPATIENT VERSUS INPATIENT MANAGEMENT
1
2
2
3
1
4
A. Saporito , S. Calciolari , L. Gonzalez Ortiz , E. Sturini , G.J. Petri , A. Borgeat , J. Aguirre
1
4
2
Anesthesiology, Bellinzona Regional Hospital, Bellinzona, Faculty of Economics, University of Italian
3
4
Switzerland (USI), Lugano, Anesthesiology, St. Chiara Clinic, Locarno, Orthopedic, Bellinzona
5
Regional Hospital, Bellinzona, Anesthesiology, Uniklinik Balgrist, Zurich, Switzerland
Background: Exploding health related costs require a reorganisation of perioperative clinical
processes in a more cost-effective way. Outpatient postoperative continuous regional analgesia after
ambulatory orthopedic surgery has been described as a safe and effective practice. It could also lead
to a reduction in hospital fix costs, but the risks of both quality of care decrease and costs shifting to
patients should be avoided. Aim of this study is to compare costs and standard of care in orthopedic
foot surgery patients treated with a continuous popliteal block in hospital and at home.
Method: After ethical committee approval, a case-control prospective study was conducted on two
continuous cohorts of patient, undergoing orthopedic forefoot surgery with a continuous popliteal
block managed either with a 72 hours long hospital stay or on an ambulatory basis (patients were left
free to decide their allocation). Both groups were treated with an ultrasound guided popliteal block
with mepivacaine 1.5% 20 ml, followed by a perineural infusion of ropivacaine 0.15% 5 ml/h through
an elastomeric pump. Patients were monitored by trained anesthetic nurses with the same follow-up
protocol either in hospital or at home by phone, in order to assess pain levels (NRS) and eventual
complications. Exclusion criteria were: patients refusal, allergy to local anesthetic, infections in the
popliteal fossa. We analysed the variability of costs through three different multiple regression models
with logarithmically transformed costs per patient as dependent variable (acute costs, post-acute
costs, and social costs, separately), the three models controlling for demographic (gender, age) and
clinical (main pathology, comorbidities) factors.
Results: A total of 163 patients were included (133 inpatient vs 30 outpatient). The two groups were
not statistically different with regard to population characteristics (sex, age, ASA class). Only 3.3% of
subjects in the day-hospital group had post-operative complications, versus 8.3% in the inpatient
group (the more frequent being persistent motor block), but this difference was not statistically
significant.
The average total acute costs per patient equals 4,975±1,889 CHF. The intra-operative phase
accounts for 36.40% of the overall costs, while the post-intervention phase and the indirect costs
account for 27.36% and 31.34% respectively. Pharmaceuticals costs represent 68.17% of total costs,
followed by readmission costs (19.90%). The inpatient group showed significantly higher average
costs for all these categories. With regard to social costs, patients' interruption costs and unpaid
informal care had the highest incidence (respectively 71.65%, and 30.93%). Patients treated in dayhospital were not associated with significantly different post-acute costs compared to inpatient cases
(p=0.07).
Conclusion: Outpatient continuous regional analgesia after orthopaedic foot surgery remains costeffective even when costs related to complications and unexpected readmissions or adjunctive
ambulatory visits are taken into account. Its cost-effectiveness does not seem to be based on a costs
shifting toward patients.
A148
A RANDOMIZED COMPARISON OF INTERSCALENE BLOCK AND COMBINED
SUPRASCAPULAR NERVE BLOCK AND AXILLARY NERVE BLOCKS FOR POSTOPERATIVE
PAIN RELIEF IN ARTHROSCOPIC SHOULDER ROTATOR CUFF REPAIR
R. Sharma, S. Dhir, S. Ganapathy
Anesthesia, St. Joseph Health Care, London, ON, Canada
Objective: Primary objective of this study is to prospectively compare and evaluate efficacy as well as
note side effects of Interscalene block (ISB) and combined Suprascapular nerve block (SSB) and
Axillary nerve block (ANB) for Arthroscopic shoulder rotator cuff repair (ARCR).
We are testing the hypothesis that SSB combined with ANB provides similar postoperative analgesia
and patient satisfaction when compared to ISB after ARCR.
Material and methods: Patients having elective ARCR are randomized to one of the two groups.
Group 1: receives ISB.
Group 2: receives SSB and ANB.
Both block groups will be ultrasound guided and nerve stimulator aided followed by a general
anesthesia.
Performance time, quality and efficacy as well as any side-effects of the blocks will be evaluated in
terms of pain scores in recovery room, after 4- 6 hours and the next morning. Opioid usage and
patient satisfaction will also be noted.
Results: These are the results of a pilot study of 7 patients. The main study is ongoing with 30
patients in each group. The results are in the table below:
Group 1
Group 2
Time for block performance
(min±SD)
3.5±0.58
6.67±0.58
Sensory block onset (min±SD)
12.5±6.45
18.33±10.4
Motor block onset (min±SD)
16.25±8.54
26.67±5.78
VAS in PACU (min±SD)
2
7.67
VAS at 4-6 hrs
1.5
6.67
VAS at 24 hrs
5.7
5
VAS at 7 days
1.3
1
Satisfaction score (PACU)
9.5
5
Satisfaction score(4-6 hrs)
9.5
6.67
[Results]
Group 1
Group 2
Satisfaction score (24 hrs) 10
6.33
Satisfaction score (7 days) 10
6.33
[Results]
Conclusion: On analysis of the pilot data, both the block groups had similar time durations in block
performance and onset of sensory and motor block. The pain scores were significantly higher and the
satisfaction scores significantly lower for group 2. Further data on the ongoing study will reveal the
effectiveness of the 2 blocks in a larger group of subjects.
1. Lee SM, Park SE, Nam YS, Lee KJ, Kwon MJ. Analgesic effectiveness of nerve block in shoulder
arthroscopy: comparison between interscalene, suprascapular and axillary nerve blocks. Knee Surg
Sports Traumatol Arthrosc (2012)20:2573-2578.
2. Chan CW, Peng PWH. Suprascapular nerve block. Reg Anesth Pain Med 2011;36:358-373.
3. Fredrickson MJ, Krishnan S, Chen CY. Postoperative analgesia for shoulder surgery: a critical
appraisal and review of current techniques. Anesthesia, 2010, 65, pages 608-624.
4. Singelyn FJ, Lhotel L, Fabre B. Pain relief after Arthroscopic shoulder surgery: A comparison of
intraarticular analgesia, suprascapular nerve block, and interscalene brachial plexus block. Anesth
Analg 2004;99:589-92
A149
ULTRASOUND-GUIDED PARAVERTEBRAL REGIONAL ANESTHESIA IN BUFFALO
M.M. Shokry, E.A. Berbish
Veterinary Surgery, Anesthesiology & Radiology, Faculty of Veterinary Medicine, Cairo University,
Giza, Egypt
th
Adequate flank regional anaesthesia was achieved using ultrasound-guided nerve block of the 13
st
nd
thoracic, 1 and 2 lumbar spinal nerves after their exits from their intervertebral foraminae with only
5 ml of lidocaine 2%. Twelve successful trials were conducted on 4 buffaloes without any
complications.
Introduction: In the last recent decades, utilization of ultrasound (US) to guide needle placement
during spatial nerve block is now well established in human patients (Harmon and Hearty, 2007;)
.Paravertebral regional block (PRB) has been the anesthetic method of choice for surgical procedures
as laparotomy , rumenotomy and caesarean section involving the flank region in buffaloes (Said,
Shokry and Fouad, 1967). However, with reference to age and size , the difficulty to establish reliable
th
st
nd
landmarks of the target spinal nerves (13 thoracic, 1 and 2 lumbar nerves) supplying the flank
region, was the reason to conduct this study.
Materials and methods: The previous anatomical study of the flank region in buffaloes by (Said,
Shokry and Fouad, 1976) has been taken as a reference for ultrasound tracing of the paravertebral
th
st
nd
nerves supplying the flank region i.e. the 13 thoracic, 1 and 2 lumbar spinal nerves at their exits
from the intervertebral foraminae. This study was conducted on 4 buffaloes (2 adults and 2 calves).
On them, 12 ultrasound-guided paravertebral nerve block trials were performed. A 20-gg 12 ml spinal
needles were also used in the procedure. Ultrasound images were presented as a single sagittal
th
st
plane with slight posterior tilting. For the 13 thoracic nerve, in between the last thoracic and the 1
st
nd
lumbar transverse processes,just behind the last rib and for the 1 and 2 lumbar nerves, in between
the succeeded lumbar transverse processes was , lateral to the midline. 5 ml of lidocaine 2% were
injected in the vicinity of each nerve trunk.
Results: Satisfactory anaesthesia of the left flank region was achieved within 2 minutes after injection
and lasted for 120 minutes. Compared with landmark-based technique, using of ultrasound greatly
improved the success rate of regional flank analgesia with minimal amounts of local anaesthetic. No
complications were recorded with all trials.
Discussion: Successful analgesia of the flank region in water buffalo was accomplished in all trials
following US-guided paravertebral blocks. The doses and concentration of the local anaesthetic ( 5 ml
of 2% local anaesthetic) were very low in comparison with the doses and concentration used in
routine blind injection (20 ml of 5% local anaesthetic) (Said et al, 1976). In this respect, US-guided
nerve block is routinely used with great success in human patients ( Harmon and Hearty, 2007).
References:
Hamon, D. and Hearty, C. Ultrasound-guided suprascapular nerve block Technique Pain Physician.
2007, 10, 743-746.
Said, AH., Shokry,MM. and Fouad,K. Paravertebral Anaesthesia in Buffaloes Zbl.Vet.Med.A, 1976,
23, 85-88.
A150
THE CUTANEOUS BRANCH OF THE SAPHENOUS NERVE - AN ANATOMICAL VARIANT
S. Singeetham, D. Auyong
Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA
Saphenous nerve blocks can provide anesthesia to the knee and medial lower extremity.
Anatomically, this nerve branches from the femoral nerve and courses through the anterior thigh in
the adductor canal. It continues as a superficial nerve distal to the knee and terminates as sensory
fibers supplying the medial leg. The adductor canal block, which anesthetizes the saphenous nerve,
has increased in popularity because it is associated with a minimal decrease in quadriceps motor
1
strength while providing analgesia after knee surgery . Objective assessment of adductor canal block
2
success is primarily limited to sensory testing of the medial leg saphenous nerve distribution .
Examination of the adductor canal shows that the saphenous nerve exits the adductor canal posterior
to the vastoadductor membrane. The vastoadductor membrane connects the vastus medialis and the
adductor muscles to form the “roof“ of the adductor canal(Image 1). Cutaneous branches of the
3
saphenous nerve can perforate the vastoadductor membrane . Most commonly, the cutaneous
branch splits from the saphenous nerve distal to the adductor canal and innervates the medial knee
4
and lower leg as the cutaneous saphenous branch . Therefore, saphenous nerve blockade
assessment from an adductor canal block is performed by examining sensation of the medial lower
leg.
During a fresh tissue cadaver dissection, we identified a variant of the cutaneous branch of the
saphenous nerve exiting 6cm caudal to the femoral crease, proximal to the adductor canal. This
superficial branch coursed anterior to the femoral artery then medial to the sartorius muscle. It
continued in the superficial plane medial to the knee and then to the lower leg as the cutaneous
branch of the saphenous nerve(Image 2). The subsartorial region was dissected to expose the
adductor canal including the vastus medialis, adductor magnus, femoral artery, saphenous nerve and
vastoadductor membrane. No portion of the saphenous nerve from the adductor canal could be
identified coursing distal to the knee joint. Thus, the only superficial cutaneous branch of this subject's
saphenous nerve did not course through the adductor canal.
This variant has at least two important clinical correlates: 1) The cutaneous branch of the saphenous
nerve may not always course through the adductor canal. Therefore, the adductor canal block may
not effectively provide anesthesia to the distal medial lower leg in all subjects; and 2) Intact sensation
of the medial lower leg does not rule out an effective adductor canal block if analgesia to the knee is
the desired outcome. Low “success” rates of saphenous nerve blocks in the literature may be a
reflection of anatomic variation. Further studies are necessary to ascertain the rate of saphenous
nerve variants.
[IMAGE 1]
[IMAGE 2]
References:
1. Anesthesiology (2013) 118:409-415.
2. Anesthesiology (2005) 102:633-638.
3. RAPM (2011) 36:399-402.
4. Surgical and Radiologic Anatomy (2007) 29:569-573.
A151
ULTRASOUND IDENTIFICATION OF GREATER PALATINE FORAMEN AND US GUIDED
GREATER PALATINE NERVE BLOCKS: A CADAVERIC STUDY
N. Sahar Hafeez, R. Sondekoppam Vijayashankar, S. Ganapathy, M. Johnson, P. Merrifield, K.A.
Galil
1
2
Anatomy, University of Western Ontario, Anesthesiology and Perioperative Medicine, London Health
Sciences Centre, University of Western Ontario, London, ON, Canada
Introduction: The greater palatine nerve block is commonly performed for maxillary and palatal
anesthesia by utilising bony landmarks like second or third molars by blind injections. The bony
landmarks are inconsistent in location leading to multiple attempts, failure or partial blockade. We
hypothesise that utilisation of ultrasound can consistently identify greater palatine foramen into which
US guided injections can consistently deposit the drug around the greater palatine nerve.
Materials and methods: 20 undissected well-embalmed hemi-sectioned cadaveric heads were used
for the study after ensuring the intactness of hard palate mucosa and ruling out major anatomical
malformations. After applying ultrasound gel over the cleaned mucosal surface, a linear high
frequency hockey stick probe (7-13MHz, Sonosite M-Turbo, Sonosite, Bothell, WA) was positioned
through the mouth in long axis to the hard palate laterally to identify dental structures as intermittent
peaks. The probe was then moved medially until visualization of the hard palate as a continuous
hyper-echoic line. The discontinuity in this line closer to the 3rd molar was identified to be the greater
palatine foramen.
[US image of Greater palatine foramen]
The probe was positioned so that US guided injections of 0.1ml India ink were made in an oblique
plane while maintaining the GPF in the centre of the screen. Each specimen was dissected
immediately after the injection to look for the distribution of the dye in relation to greater palatine
nerve, greater palatine foramen and greater palatine canal. Success rate of identification of GPF was
the primary objective. The number of needle pass and success rate of injections at the GPF was also
calculated. The cases were termed failure if the foramen was not identified with 2 attempts at
scanning.
Results: Greater palatine foramen was successfully identified in all the 16 hemi-sectioned heads
(100%) although 4 (25%) cases required more than one attempt for identification. The identification of
GPF was successful in edentulous cadavers also. In one case (6.25%), the greater palatine foramen
was identified as a step like defect in the hard palate with the foramen pointing anteriorly. In 7 out of
16 hemi-sectioned cadaveric specimens (43.75%), needle pass was seen on the US and traces of
India ink were found within the Greater palatine canal and pterygopalatine fossa. In the rest of the 9
specimens, although the injections were made after successful identification of GPF, the needle of the
syringe could not be visualised entering the foramen and the dye was observed in the mucosal tissue
of the hard palate anterior to the GPF. In two specimens, traces of dye were found in the tissue of soft
palate (1.25%).
Conclusion: Ultrasound has the potential to successfully locate GPF and its variations in normal and
edentulous maxilla. The performance of US guided greater palatine nerve blocks in living patients
might be easier due to better echogenicity of tissues than in embalmed cadavers and by the ability to
identify accompanying artery by ultrasound. Ultrasound has the potential for application in dental
blocks like greater palatine nerve blocks.
A152
THE CHANGES AND FUNCTION OF MICRORNA 23B IN SPINAL CORD IN THE SPINAL NERVE
LIGATION MODEL OF NEUROPATHIC PAIN
P.-H. Tan, C.-C. Liu
1
2
Anesthesiology, E-DA Hospital/I-Shou University, Biological Sciences, National Sun Yat-Sen
University, Kaohsiung, Taiwan R.O.C.
Introduction: Neuropathic pain resulting from nerve lesions or dysfunction represents one of the
most challenging neurological diseases to treat. microRNAs (miRNAs) are small noncoding transcripts
that can control expression of protein-coding mRNAs at the posttranscriptional level and play an
important role in regulating synaptic plasticity. Significant up-regulation of miRNA-23b in spinal cord
was noted in our microarray miRNA profiling in neuropathic pain. Previous study found the
involvement of miR-23b in the regulation of mouse µ opioid receptor(1,2). We hypothesized the upregulation of mir-23b play a role in the induction of neuropathic pain. Thus, in this study, we examined
the antinociception produced by inhibition of mir-23b in spinal cord for neuropathic pain.
Material and methods: Spinal nerve ligation (SNL), a model of neuropathic pain, was performed to
induce neuropathic pain. In treatment groups, 2 nmole locked nucleic acid (LNA) LNA-mir-23b
inhibitor or scrambled LNA-mir-23b inhibitor were administered 3 days after SNL. Behavioral tests
were performed before or 5 days and 10 days after injection of LNA-mir-23b inhibitor or scrambled
LNA-mir-23b inhibitor. The spinal cord was dissected for analysis of mir-23b after behavioral test
performed at 5 and 10 days after injection of LNA-mir-23b inhibitor or scrambled LNA-mir-23b
inhibitor. Rats received SNL only were assigned to be another control group. The spinal cord was
dissected for analysis of mir-23b 3 days after SNL. The analysis of mir-23b was preformed by
quantitative real-time polymerase chain reaction and in-situ hybridization.
Results: Significant increase of mir-23b was noted in spinal cord of rats received SNL only.
Intrathecal injection of 2 nmole LNA-mir-23b inhibitor could effectively diminish SNL-induced allodynia
and thermal hyperalgesia on day 5 and day 10 after injection of LNA-mir-23b inhibitor. The expression
of miRNA-23b in spinal cord was significant decreased on day 5 and 10 after injection of LNA-mir-23b
inhibitor compared with rats received SNL alone.
Conclusions: This study provides evidence that SNL induces up-regulation of mir-23b in spinal cord
and inhibition of mir-23b produces antinociceptive effect for neuropathic pain.
References:
1. Wu Q, Law PY, Wei LN, Loh HH (2008) Post-transcriptional regulation of mouse mu opioid receptor
(MOR1) via its 3' untranslated region: a role for microRNA23b. FASEB J 22:4085-4095.
2. Wu Q, Zhang L, Law PY, Wei LN, Loh HH (2009) Long-term morphine treatment decreases the
association of mu-opioid receptor (MOR1) mRNA with polysomes through miRNA23b. Mol Pharmacol
75:744-750.
Funding: This work was supported by National Science Council Grant NSC 100-2314-B-214-002MY3 and NSC 101-2321-B-214 -001, Taiwan.
A153
CAN PARALLEL USE OF REGIONAL BLOCK ROOM SHORTEN THE ANESTHESIA
UTILIZATION TIME IN ORTHOPEDIC SURGERY?
S. Tangwiwat, A. Iamaroon, A. Lurngnateetape, K. Chareancholvanich, C. Nuntawinit
1
2
3
Anesthesiology, Orthopedic Surgery, Nursing Siriraj Hospital, Faculty of Medicine Siriraj Hospital,
Mahidol University, Bangkok, Thailand
Introduction: Application of regional anesthesia (RA) can be time consuming, thus interfering with
surgical schedule. We hypothesized that running a block room parallel to the operating rooms for
performing RA reduces the anesthesia utilization operating room(OR) time in orthopedic surgery, thus
increasing efficiency of daily schedule.
Material and methods: After Institutional Review Board (IRB) approval, a prospective study was
performed from January till June 2012 including orthopedic operations without spine surgery. Parallel
to the ORs a special 'block room' was run by an anesthetic team to apply selective or additional (to
GA) RA procedures. The following data were recorded: demographic characteristics, anesthesia
techniques, RA location, anesthesia utilization time before and after surgery, surgical preparation
time, operation- and turnover time. We also recorded the first case on-time start (9 AM) and the
number of cases running after 4 PM.
Results: Of 1,726 orthopedic procedures, 883 (51.2%) had RA, 288 (16.7%) combined GA + RA and
555 (32.2%) GA alone. RA was performed in either the block room (21.5%) or the OR (71.8%) or both
locations (6.7%). Compared to the usual schedule the availability of a block room significantly
reduced the anesthesia utilization time but not the turnover time as shown in the Table. On-time start
(9:00AM) of the first case was only 38%. Cases running after 4 PM were 3.7 (mean) per day and 50%
of overutilized OR time cases were finished at 4 to 5 PM.
Anesthesia techniques
Time ( min)/case
Median (IQ range)
GA
RA in OR
RA in block room
GA+ RA
Anesthesia preprocedure time
15 (10-25) *
5 (5-5)
25 (20-35) *
Anesthesia postprocedure time
5 (5-10)**
5 (3-5)
5 (3-5)
5 (5-10) **
Anesthesia Pre +
post time
25 (18-35) ***
25 (20-35)***
10 (8-14)
35 (25-45)***
Surgical
preparation time
15 (10-20)
20 (15-25)****
15 (10-25)
15 (10-25)
Surgical time
55 (25-100)+
100 (70-125)
90 (65-115)
104 (70-145)+
Turnover time
10 (5-15)
10 (5-15)
5 (5-10)
10 (5-15)
*, **, ***, ****, + = P < 0.05 when compared to RA in block room
[Table]
Discussion: Using a block room as additional workstation resulted in reduced perioperative
anesthesia-controlled time. RA procedure in OR is time-consuming. Time usage for RA in OR was
longer than GA. Turnover time was unaffected by anesthetic techniques. Future studies should
investigate if using a block room can improve the OR time efficiency.
References:
1. Mariano ER, Chu LF, Peinado CR, Mazzei WJ. Anesthesia-controlled time and turnover time for
ambulatory upper extremity surgery performed with regional versus general anesthesia. J Clin Anesth
2009 ;21(4):253-7.
2. Armstrong KP, Cherry RA. Brachial plexus anesthesia compared to general anesthesia when a
block room is available. Can J Anaesth 2004 ;51(1):41-4.
3. Eappen S, Flanagan H, Lithman R, Bhattacharyya N. The addition of a regional block team to the
orthopedic operating rooms does not improve anesthesia-controlled times and turnover time in the
setting of long turnover times. J Clin Anesth 2007 ;19(2):85-91.
Funding: Research grant of the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok
Thailand
Personal conflicts of interest disclosure: Nothing to disclose
A154
EFFICACY AND SAFETY OF THREE DIFFERENT APPROACHES FOR ULTRASOUND GUIDED
FEMORAL NERVE BLOCK FOR PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY
A. Tharian, S. Gonzales, N. Niemiec, S. Saatee, R. Omar, R. Sauer, L. Chupatanakul, K.D. Candido,
N.N. Knezevic
1
2
Anesthesiology and Pain Medicine, Advocate Illinois Masonic Medical Center, Anesthesiology,
University of Illinois at Chicago, Chicago, IL, USA
Introduction: Total knee arthroplasty (TKA) causes considerable postoperative pain. It can prolong
hospitalization, impair rehabilitation and early mobilization, and may worsen functional outcome.
Effective postoperative pain control following TKA lowers the risk of postoperative complications, such
as thromboembolic disease and nosocomial infection. Patient-controlled IV analgesia with opioids is
associated with side effects (nausea, vomiting, pruritis, ileus, urinary retention, sedation and
respiratory arrest), which could delay the initiation of physical therapy. Femoral nerve blocks (FNB)
have been shown to significantly improve postoperative analgesia and have less side effects as
compared with opioid therapy.
Objective: The purpose of this prospective, single blinded, randomized study was to determine
efficacy and safety of three different approaches for ultrasound guided FNB: single-shot femoral nerve
block (SFNB), continuous femoral nerve block (CFNB) with non-stimulating catheter, and CFNB with
stimulating catheters.
Material and Methods: We enrolled 53 patients (ages 18-90 years) undergoing TKA in this pilot
study. All patients were randomly assigned to one of three groups (SFNB, CFNB with non-stimulating
catheter, and CFNB with stimulating catheter). We excluded patients who had redo surgery on the
ipsilateral knee, radicular pain in the same leg, BMI ≥45, allergy to local anesthetics, opioid
habituation, neuropathy of any etiology in the surgical extremity or any contraindications to regional
block. All blocks were performed under ultrasound guidance combined with neural stimulation. All
patients were evaluated in the PACU at arrival (time 0), 30 minutes and 1 hour after arrival in the
PACU, and then at 12, 24 and 48 hours after the surgery. All patients were assessed for ability to
move the knee, numeric pain scores, amount of supplemental pain medications and overall
satisfaction of the patient with pain control.
Results: There was no statistically significant difference between these three groups with respect to
age, gender, height, weight, total block time, total surgery time or needle depth (p>0.05).
[Table1]
From our preliminary results, patients from CFNB with non-stimulating catheters had better pain relief
at rest (at 24 and 48 hours) and during the movement (30 minutes, 1 hour, 12 hours) as compared
with SFNB and CFNB with stimulating catheters. There was no statistically significant difference in
amount of PCA opioid consumption during the 48 hours after surgery.
[Figure]
Conclusion: Single-shot femoral nerve block (SFNB) and continuous femoral nerve block (CFNB)
comprise the two main peripheral blocks used in contemporary practice for TKA. Stimulating catheters
are sometimes used in CFNB with the presumption that they aid in placing the catheter closer to the
targeted nerve thereby providing superior analgesia. There have been studies showing the benefit of
SFNB and CFNB individually, comparing SFNB and CFNB, as well as comparing stimulating and nonstimulating catheters in CFNB. However, this is the first study comparing all three techniques in
relation to postoperative pain control and rehabilitation, showing slightly better results with nonstimulating CFNB. A longer follow up and the enrollment of more patients will clarify statistical and
clinical significance.
A155
PRELIMINARY REPORT: RETROSPECTIVE REVIEW OF DURATION OF SINGLE SHOT
POPLITEAL SCIATIC NERVE BLOCKS FOR FOOT AND ANKLE SURGERY
J. Thomas, J. Li, F. Dai, R. Wardhan
Anesthesiology, Yale University, New Haven, CT, USA
Introduction: Real time ultrasound guidance for popliteal sciatic block is considered to be a
successful technique for providing anesthesia/analgesia for foot and ankle surgery. Ultrasound
guidance results in higher success, faster onset, and progression of sensorimotor block, without an
increase in block procedure time, or complications when compared to nerve stimulation only.
Method: Ultrasound guided single shot popliteal sciatic blocks are routinely performed in our institute
on patients undergoing ankle and foot surgery. We used our perioperative database to identify all
patients who underwent ankle and foot surgery performed by one surgeon from July 2011 through
December 2012. This is a retrospective database study and these results constitute an interim
analysis. The information collected includes gender, age, volume of local anesthetic used, duration of
nerve block & postoperative pain scores.
Results: After IRB approval for chart review, 53(29 females,24 males) ASA I-III patients were
analyzed.All patients underwent an ultrasound guided popliteal sciatic block utilizing varying volumes
of 0.5% ropivacaine. Average duration of block was 22(7-3)hrs.No statistically significant (negative
correlation via Spearman rank correlation coefficient = -0.13, p-value = 0.38) was observed between
duration of block (hrs.) and volume of Ropivacaine 0.5% (ml) in these 53 patients.
Discussion: Many studies have been performed to determine the effect of volume vs. concentration
on the onset and duration of various nerves. Latzke et al even determined the minimum effective
volume of local anesthetic required to block sciatic nerve, however confusion still exists on whether
higher volume or concentration results in longer duration of sciatic nerve block .The goal of this study
is to retrospectively ascertain duration from commonly used volumes by regional anesthesiologists.
Latzke D, Marhofer P, Zeitlinger M, Machata A, Neumann F, Lackner E and Kettner S C 2010 Minimal
local anaesthetic volumes for sciatic nerve block: evaluation of ED 99 in volunteers Br J Anaesth 104
239-44
Perlas A, Brull R, Chan V W, McCartney C J, Nuica A and Abbas S 2008 Ultrasound guidance
improves the success of sciatic nerve block at the popliteal fossa Reg Anesth Pain Med 33 259-65
A156
USE OF IMPEDANCE AS A TOOL TO RECOGNIZE INTRANEURAL NEEDLE PLACEMENT: A
STUDY EXTRAPOLATING CADAVER FINDINGS TO MEASUREMENTS IN AMPUTATED LIMBS
1
1
1
1
1
2
A. Vydyanathan , M.V. Tu , S. Nair , S. Huch , Z. Khan , A. Kaufman , N. Shaparin
1
1
Anesthesiology and Pain Medicine, Albert Einstein College of Medicine/Montefiore Medical Center,
2
New York, NY, Anesthesiology and Pain Medicine, UMNDJ Robert Wood Johnson Hospital, Newark,
NJ, USA
Introduction: Injury to peripheral nerves is a very rare but devastating complication of peripheral
nerve blocks. While the incidence is 4-10/1000 nerve blocks, most of these injuries are transient but a
few are permanent and disabling (1). While the use of ultrasound has revolutionized the field of
regional anesthesia, it has not been shown to improve safety and prevent intraneural injections (2).
The use of electrical stimulation with the standard of amperage >0.2 mA as preventing intraneural
placement is also questionable (3). Pressure of injection has not been shown to consistently correlate
with intraneural injection. Recently impedance has shown promise as a marker of intraneural
placement in an animal study (4). This study was done to study impedance as a marker of intraneural
needle placement in human models.
Methodology: The first part of the study was done in cadaver dissections and the impedance
measurements were done using a 21G Stimuplex needle on the sciatic nerve in the popliteal fossa in
2 cadavers. The measurements were done to assess perineural and intraneural impedance with 2-3
passes on each nerve.
It was desired to obtain the impedance values for intraneural and perineural needle placement on
fresh nerves. As it is not ethically possible to place a needle intraneurally in living subjects, we
decided to take freshly amputated lower extremities and obtain these impedance measurements on
the sciatic/tibial nerve within 1 hour of amputation. The impedance values were obtained for
perineural placement followed by intraneural placement initially using ultrasound guidance and then
by open dissection to expose the nerve.
Results:
Cadaver study: The initial cadaver values were obtained from 3 sciatic nerves after open dissection.
The perineural impedance was 7.6±1.1 kΩ and intraneural impedance was 9.1±1.1 kΩ, an increase of
20%.
Amputated limb values: Impedance values have been obtained from 2 amputated limbs thus far. The
values obtained are as shown in graph 1. As seen in the graph, the impedance values using
ultrasound guidance and open dissection are comparable and there is a 73% increase in impedance
values as the needle progresses from the perineural to the intraneural space.
[Peri- and intra-neural Impedance values in kΩ ]
Conclusion: Our early data shows an increase in impedance as the needle passes from the
perineural to intraneural space, therefore adding impedance measurement as a tool while using
ultrasound guidance in performing regional anesthesia could help further reduce the incidence of
intraneural injections.
References:
1. Barrington MJ, Watts SA, Gledhill SR, Thomas RD, Said SA, Snyder GL, Tay VS, Jamrozik K. Reg
Anesth Pain Med. (2009); 34(6): 534-41.
2. Neal JM. Reg Anesth Pain Med. (2010); 35(2 Suppl): S59-67.
3. Sala-Blanch X, López AM, Pomés J, Valls-Sole J, García AI, Hadzic A. Anesthesiology (2011);
115(3): 589-95.
4. Tsui BC, Pillay JJ, Chu KT, Dillane D. Anesthesiology. (2008); 109(3): 479-83
A157
SPINAL CORD STIMULATION EFFICACY: REVIEW OF 7 YEARS' EXPERIENCE FROM AN
ACADEMIC CENTER DATABASE
L. Tunke, E. Veizi, S. Hayek
Case Western Reserve University Medical School-University Hospitals of Cleveland, Cleveland, OH,
USA
Introduction: Spinal cord stimulation (SCS) is an ever growing field that has been widely applied to
treat intractable pain entities since 1967. Accepted indications include postlaminectomy pain, CRPS,
peripheral neuropathy, and visceral pain. Several authors have reported case series and few
randomized trials (Kemler et al 2005; North et al 2008). Robust analysis in large SCS patient
registries is very useful.
Purpose: The purpose of this study is to report the 7 year experience of an academic pain medicine
practice on the use of SCS for chronic nonmalignant pain.
Study design: This is a retrospective single center database review of all SCS trials/implants. Over a
7 year period (2006-2013) in a single academic center 345 patients were subjected to a trial of SCS.
234 patients had a satisfactory outcome (>50% improvement in pain and activity) to justify a
permanent implant.
Results: Trial/implant ratio in the general population was 67.8% and disease specific was 67.8% for
FBSS, 68.2% for CRPS, 83.3% for SFN and 68.4% for PHN/PN and 71.4% for visceral pain post
differential nerve block. NRS cores decreased from 8.4 to 3.2 at 1 month and 5.5 at 12 months. The
number of back surgeries was not correlated with the satisfaction leading to SCS implant (14% of
patient on failed trail group and 15% on successful trial group).
Conclusions: SCS can provide significant long term relief in various conditions with chronic
intractable pain. Stringent patient selection and rigorous assessment of the pain quality affects the
efficacy of this treatment.
A158
COMPARISON OF USAGE OF NEUROSTIMULATOR ONLY AND NEUROSTIMULATOR
TOGETHER WITH ULTRASONOGRAPHY IN BRACHIAL PLEXUS BLOCK WITH REGARD TO
BLOCK SUCCESS, COMPLICATIONS AND PATIENT SATISFACTION
E. Keles, A. Turkmen, Z. Ervatan, E. Denizli
Anesthesiology and Reanimation, Ministry of Health Okmeydani Training & Education Hospital,
Istanbul, Turkey
The purpose of this study is to investigate the effects of block success, complications and patient
satisfaction of ultrasonography usage in axillary brachial plexus blockage.
50 patients with ASA I-III, over 20 years of age to whom forearm and hand surgery would be
performed were included in this study after approval of the ethical committee and informed consent of
the patients were obtained. Heart rate, noninvasive blood pressure and peripheral oxygen saturation
of the patients were monitored, for whom demographic data were recorded. 2 mg midazolam was
administered intravenously half an hour before the application. Brachial plexus blockage was applied
in group I (n=25) using neurostimulator only and in Group II (n=25) ultrasonography guided
neurostimulator. Procedure time, number of needle insertions, existence of vascular puncture was
recorded. Pain felt by the patient during the treatment was recorded by examination with pain scoring.
Sensory block developed was controlled with pin-prick test and motor block developed was evaluated
with Holmen scale. Operation was started after block formation times were recorded. Need for general
anesthesia was recorded. Patients were questioned in the recovery room after the operation if they
were pleased with the anesthesia method performed and the answer was recorded.
Demographic data, motor and sensorial block onset time, operation and procedure times and pain
scores were found to be similar in Group I and II. 2 patients required anesthesia in group I and 3
patients stated that they were unsatisfied, but no statistically significant difference was detected.
Number of needle insertions and vascular puncture were significantly lower in Group II.
As a conclusion, block success and patient satisfaction in axillary brachial plexus blockage performed
using neurostimulator together with ultrasonography were found to be similar and complication rate
was found to be significantly lower.
A159
THE ANGLE OF NEEDLE INSERTION DURING ULTRASOUND-GUIDED LATERAL SAGITTAL
INFRACLAVICULAR BRACHIAL PLEXUS BLOCK
1
2
3
3
V. Uppal , H.K.P. Kalagara , S. McKinlay , A.J.R. Macfarlane , K. Anderson
1
4
2
Department of Anesthesia, London Health Sciences Centre, London, ON, Canada, Anesthesiology
3
Institute, Cleveland Clinic, Cleveland, OH, USA, Department of Anesthesia, Glasgow Royal Infirmary,
4
Glasgow, UK, Department of Anesthesia, Foothills Medical Centre, Calgary, AB, Canada
Introduction: Infraclavicular brachial plexus block (IBPB) is particularly useful for elbow, forearm and
hand surgery. Whilst real time ultrasound (US) increases the success of this block [1] needle
visualization can be difficult [2], despite previously published US and MRI data suggesting a shallow
angle of approach [3]. The primary aim of our study was to establish the angle of needle insertion
from the anterior chest wall during US guided IBPB in our patients. Our secondary aim was to
examine for any correlation between BMI and insertion angle.
Methods: Local research ethics committee approval was sought and deemed not necessary for this
prospective observational study. A 38 mm linear probe was placed in the parasagittal plane in the
deltopectoral groove just medial to coracoid process. The needle was inserted in-plane to the
ultrasound beam aiming for the needle tip to be at 6 o'clock position to axillary artery. The angle of
needle insertion in relation to the anterior chest wall was measured using Screen Protractor 4.0
(Iconico, 75 East 4th Street, New York).
Results: 23 patients were studied, all Scottish-Caucasian. Thirteen patients also received a general
anaesthetic as planned. The results are shown in table 1. Values expressed as mean [range], mean
(SD) or absolute.
Gender (M: F)
13:10
Weight (kg)
82.3 (17.6)
Body mass index (kg m-2)
28.5 (5.4)
Angle (degree)
50 [33-60]
Depth from chest wall to 6 o'clock position (cm) 3.5 [2.1-4.5]
Length of needle insertion (cm)
4.8 [3.4-5.8]
Needle visibility (Static/Dynamic/Hydrolocation) 9/5/9
'Heeling-in' required? (Yes/No)
9/14
Quality of block (Good/Incomplete/Nil)
22/1/0
Visualization of needle (Easy/Moderate/Difficult) 5/11/7
[Table 1]
The Pearson correlation coefficient for BMI and angle of needle insertion was 0.357. The needle
insertion angle was significantly greater in BMI>29 compared to BMI< 29 (p=0.0479). ROC (receiver
operating curves) analysis suggested that a BMI>35 best predicted difficult needle visualization
(Likelihood Ratio 7.5 [95%CI 0.8-182.6]).
Discussion: The median angle of needle insertion in relation to chest for our study patients was 50
degree which is much steeper than reported by other researchers [3], possibly due to either
anthropological differences between Scottish and Scandinavian patients or a slight difference in the
plane of measurement between our work and the previously reported data. Needle visibility was
difficult, requiring hydrolocation or 'heeling-in' in 39% of cases. There was a moderate correlation
between BMI and angle of insertion. Despite difficulties with needle visualization, the IBPB provided
reliable analgesia.
References:
1. Dingermans et al. Anesthesthesia Analgesia 2007; 104: 1275-80
2. Macfarlane et al. Continuing Education in Anaeshesia, Critical Care & Pain 2009; 9: 139-143
3. Sauter et al. Anesthesia & Analgesia 2008; 106: 1910-5
Funding disclosure: Only departmental funds were used for this study. No external funds were
obtained
Personal conflicts of interest disclosure: Nothing to disclose
A160
A NOVEL MODIFIED RETROCRURAL APPROACH FOR CELIAC PLEXUS BLOCKADE: THE
SINGLE-NEEDLE RETROAORTIC TECHNIQUE
S. Volney, M. Kamdar, D. Edwards, A. Thabet, J.P. Rathmell
Massachusetts General Hospital, Boston, MA, USA
Introduction: Celiac plexus neurolysis is a well-established technique shown to improve upper
abdominal cancer-related visceral pain when compared to systemic analgesics alone [1]. While the
transcrural celiac plexus approach is the most commonly performed technique, literature suggests
that if there is tumor burden in the vicinity of the celiac axis such as in the body or tail of the pancreas,
the transcrural approach may be less efficacious [2]. In this instance administration of neurolytic to the
retrocrural space targeting the thoracic splanchnic nerves may be more effective. Traditionally the
retrocrural approach often requires bilateral needle entry to facilitate neurolytic spread to the
splanchnic nerves on both sides of the aorta. In some instances anatomic barriers such as visceral
structures and bony abnormalities preclude safe needle trajectory to bilateral retrocrural target sites.
We describe a novel, single-needle retroaortic, modified-retrocrural approach for the treatment of
intractable upper abdominal malignancy pain in five patients, in whom the traditional transcrural or
bilateral retrocrural approaches were not feasible.
Methods: Five patients with pancreatic adenocarcinoma and intractable upper abdominal pain
presented for celiac plexus neurolysis under CT guidance. The ages of the patients ranged from 57 to
81 years. Anatomic barriers such as deep pleura (Fig. 1) and an enlarged liver (Fig. 2) precluded safe
access using a conventional bilateral retrocrural approach. Neurolysis was delivered using a 22gauge Chiba needle initially advanced into the retrocrural space clear of anatomic obstructions and 812 mL of 100% ethanol was injected. Subsequently, the needle was advanced further; posterior to the
aorta, into the contralateral retrocrural space and another 8-12 mL 100% ethanol was instilled. Preand 4 week post-intervention pain scores were recorded.
Results: All patients had significant pain relief immediately after the procedure. Pre-intervention pain
scores ranged from 6-8/10 on an 11-point numerical rating scale (Mean 6.8). Four-week follow up
post-intervention pain scores ranged from 0-4/10 (Mean 1.2). There was a mean pain reduction of
5.6/10 (p< 0.005, 95% CI 2.88 to 8.32). Post-intervention contrast demonstrated bilateral retrocrural
spread in all cases. There were no significant complications.
Discussion: This novel technique represents an effective option when transcrural or traditional
bilateral retrocrural routes are not technically practical. The retroaortic approach may be most
applicable for patients with excessive tumor burden near the celiac axis and anatomic barriers
precluding traditional a bilateral retrocrural approach. Although we demonstrated safe and effective
use of this technique in 5 patients, controlled studies will be needed to further elucidate the safety and
efficacy of this approach as compared to traditional methods.
References:
1. Wong, G.Y., et al., Effect of neurolytic celiac plexus block on pain relief, quality of life, and survival
in patients with unresectable pancreatic cancer: a randomized controlled trial. JAMA, 2004. 291(9): p.
1092-9.
2. Rykowski, J.J. and M. Hilgier, Efficacy of neurolytic celiac plexus block in varying locations of
pancreatic cancer: influence on pain relief. Anesthesiology, 2000. 92(2): p. 347-54.
[Figures 1 & 2 Retroaortic retrocrural approach]
A161
AN ALGORITHMIC APPROACH TO PLANNING AND PERFORMING CT-GUIDED CELIAC
PLEXUS NEUROLYSIS FOR CANCER-RELATED PAIN
S. Volney, M. Kamdar, A. Thabet, J.P. Rathmell
Massachusetts General Hospital, Boston, MA, USA
Introduction: Image-guided celiac plexus neurolysis is an effective therapeutic option in the
management of visceral pain related to upper abdominal malignancies [1,2]. With the advancement of
multidetector computed tomography (CT), clinicians are turning to CT guided neurolysis as standard
of care for percutaneous celiac plexus neurolysis, owing to its clear resolution of anatomic structures
which allows optimal pre-procedure planning and intra-procedure visualization. In order to safely and
effectively perform CT-guided celiac plexus neurolysis, numerous variables must be considered. For
example selection of optimal approach based on tumor location and anatomic barriers, transcrural vs.
retrocrural approach, single vs. bilateral needle technique, patient positioning, CT gantry angulation,
and neurolytic injectate volume must all be meticulously considered through a clear, methodical
approach. Review of the literature demonstrates a lack of a practical, systematic, algorithmic method
to planning and performing safe and successful CT-guided celiac plexus neurolysis. Here we propose
and evaluate a simple stepwise algorithm to facilitate CT-guided celiac plexus neurolysis.
Methods: Eight patients with pancreatic cancer were identified to be candidates for celiac plexus
neurolytic blockade under CT guidance. Pancreatic tumor location included 5 patients with pancreatic
body/tail disease and 3 with tumor localized to the pancreatic head. Pre-procedure planning and CT
guided neurolysis was performed using a proposed systematic algorithm based on celiac plexus
targets, pancreatic tumor location, and anatomic barriers (Fig. 1). Pre- and 4-week post-intervention
pain scores were recorded.
Results: Celiac plexus neurolysis was safely and effectively performed on all patients. Preintervention scores ranged from 4-10/10 on an 11-point numerical rating scale (mean 7.38). Fourweek follow up pain scores ranged from 0-7/10 (mean 2.13). There was a mean pain reduction of
(5.25) (p< 0.002, 95% CI 2.91 to 7.66). Post-intervention contrast demonstrated adequate bilateral
neurolytic spread in all cases. There were no significant procedural complications.
Discussion: With consideration of the numerous variables involved in planning and performing a
successful CT-guided celiac plexus neurolysis, we have developed a practical and stepwise
procedural algorithm for clinicians. While further data needs to be gathered on a larger number of
patients, this algorithm appears to be both safe and effective. This algorithm may be most applicable
to clinicians who are relatively new to performing CT-guided celiac plexus neurolysis for pancreatic
cancer pain.
References:
1. Wong, G.Y., et al., Effect of neurolytic celiac plexus block on pain relief, quality of life, and survival
in patients with unresectable pancreatic cancer: a randomized controlled trial. JAMA, 2004. 291(9): p.
1092-9.
2. Eisenberg, E., D.B. Carr, and T.C. Chalmers, Neurolytic celiac plexus block for treatment of cancer
pain: a meta-analysis. Anesth Analg, 1995. 80(2): p. 290-5.
[Figure 1 Celiac plexus neurolysis algorithm]
A162
ASSOCIATIONS OF PSYCHOSOCIAL AND DEMOGRAPHIC FACTORS WITH ACUTE PAIN
FOLLOWING TOTAL KNEE ARTHROPLASTY
1
1
1
1
2
1
1
C.M. Greco , K.L. Vulakovich , D. Landsittel , I. Belfer , F. Dai , L. Crossett , J. Chelly
1
2
3
4
Psychiatry, Anesthesiology, University of Pittsburgh, Pittsburgh, PA, Yale University, New Haven,
CT, USA
Introduction: Psychosocial factors such as anxiety, depression, and catastrophizing about pain have
been implicated as contributors to the pain experience. The purpose of this study was to evaluate
associations between psychosocial and demographic variables and acute pain post-total knee
arthroplasty (TKA).
Materials and methods: After completing informed consent at a baseline visit, 153 Caucasian adults
scheduled for unilateral TKA surgery at the University of Pittsburgh Medical Center underwent clinical
evaluation and completed self-report psychosocial questionnaires: Anxiety, Depression, and Sleep
disturbance were assessed using the NIH roadmap initiatives' Patient Reported Outcomes
®
Measurement Information System (PROMIS ) static forms (www.nihpromis.org), the Perceived
Stress Scale, the Somatization scale from the Brief Symptom Inventory-18, the Pain Catastrophizing
Scale, and the Neuroticism scale from the Big 5 Personality Inventory. Pain was assessed via patientreported numeric rating scale (NRS) (0-10) of pain with movement and pain with pressure during
clinical examination at the pre-surgery baseline visit and on day 2 post-surgery. Data analyses
included robust linear regression analyses to evaluate simple and multivariable associations between
demographic and psychosocial variables and level of pain on day 2 post-surgery. Any single variable
found to be associated with pain at p< 0.10 level of significance was included in multivariable models,
which were considered significant at p< 0.05.
Results: The average age of participants was 64 years (SD=8.8) and ranged from 40 - 88. The
majority of participants were female (58%). Forty-six percent had a household income of < 60K per
year. At the baseline visit, the majority of participants rated their pain with movement and with
pressure as “none/mild.” On day 2 post-surgery, 74 (48.5%) reported moderate/severe pain (defined
as NRS >3) with movement and 20 (13%) reported pain with pressure as moderate/severe. In simple
robust linear models to predict day-2 pain with movement (adjusted for baseline pain), lower income
was marginally associated with pain with movement (p= 0.077). For the outcome variable pain with
pressure, gender (p< 0.001), Somatization (p=0.10), and the Hopelessness subscale of the Pain
Catastrophizing Scale (p=0.05) were significant in simple robust linear models adjusted for baseline
pain. These three variables were included in the multivariable model for pain with pressure along with
baseline pain. The overall model was significant at p< 0.001, and gender remained significantly
associated with pressure pain (t=-5.37, p< 0.001).
Coefficient
P value
[95% Conf. Interval]
Baseline pain with
pressure
0.19
0.141
-.0640215 .4465779
Female gender
-2.09
<0.001
-2.855827 -1.316902
Somatization
-0.66
0.138
-1.542587 .2161941
Hopelessness
-0.002
0.974
-.1036909 .1003167
[Pain with Pressure on post surgery day 2]
Discussion: We found that a large proportion of TKA patients experience moderate to severe pain
post-operatively. Female gender was significantly associated with having less pain with pressure postTKA when controlling for baseline pain, hopelessness, and somatization. In contrast to a recent study
of TKA patients, psychological factors such as depression were not associated with acute pain postsurgery.
Funding disclosure: NIH/NIDCR (0408-CT2048) PI Dr. Jacques Chelly.
No Conflicts of Interest to Disclose.
A163
CAN ULTRASOUND GUIDANCE REDUCE THE VOLUME AND CONCENTRATION OF LOCAL
ANESTHETICS FOR SUCCESSFUL INTERSCALENE BRACHIAL PLEXUS BLOCK? A
SYSTEMATIC REVIEW
J.J. Wang, C. Margarido, M. Tavakkolizadeh, C.J.L. McCartney
Department of Anesthesia, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
Introduction: Reducing the dose of local anesthetic (LA) required for interscalene brachial plexus
1
block (ISBPB) improves its safety by decreasing the risks of systemic toxicity and block side effects
2,3
4,5,6
such as phrenic nerve palsy. Since ultrasound-guidance increases block efficacy,
it has been
used to investigate the effects of reduced LA dose on block success, duration and incidence of
2-14
phrenic nerve palsy.
We aim to summarize the effect of low-dose ultrasound-guided ISBPB on
block efficacy.
Methods: Medline, Medline in-process, Embase, Cochrane Central Register of Controlled Trials and
Cochrane Database of Systematic Reviews were searched to retrieve randomized controlled trials
(RCTs) and prospective observational trials studying ultrasound-guided ISBPB for shoulder surgery
using less than established LA volumes (20ml for analgesia and 40ml for anesthesia). Outcome
measures included block success, duration and incidence of phrenic nerve palsy. Methodological
15
quality was determined using the Thomas Quality Assessment Tool for observational trials and the
16
Cochrane Collaboration's Tool for RCTs .
Results: The electronic databases identified 199 abstracts, of which 61 were duplicates, and 37 did
not meet inclusion criteria. 13 of the 24 full articles reviewed met criteria, representing 614 patients. A
moderate dose-response correlation(Figure1) between block success and log dose, volume and
concentration was established through weighted linear regression. The predicted effective dose(ED)
95(95%CI) for successful ultrasound-guided ISPBP with ropivacaine was 106mg(23-148) for dose,
18ml(4-24) for volume at 0.5%, 15ml(2-22) for volume at 0.75%, and 0.56%(0.24-0.72) for
concentration at 20ml. Block duration did not correlate with LA dose(Figure2) or volume. Phrenic
nerve palsy showed a moderate-high dose-response correlation with LA dose and volume. The
predicted ED95(95%CI) for normal diaphragmatic function was 20mg(16-51) for ropivacaine dose and
3.5ml(2.7-7.4) for ropivacaine volume at 0.75%.
Discussion: Ultrasound-guidance can reduce LA dose for ISBPB while maintaining block efficacy,
although block success can be compromised by very low LA doses(< 40mg). The conservation of
block duration at doses which reduce block success suggest that once LA is accurately deposited,
even very low volumes can maintain shoulder analgesia. The wide confidence intervals reflect small
sample sizes (15-40 patients per allocation), as well as heterogeneity between trials regarding block
technique (single or multiple injections; single-shot or catheter), operator experience (single or
multiple), and surgery subtypes (open or arthroscopic). Therefore, future RCTs studying the effect of
LA dose on ISBPB efficacy are still necessary.
[Figure 1: Block success vs. ropivacaine dose]
[Figure 2: Block duration and ropivacaine dose]
References:
1. Minerva Anesthesiol. 2010;76:1088-1090
2. Reg Anesth Pain Med. 2009;34:498-502
3. Can J Anaesth. 2011;58:1001-1006
4. Br J Anaesth. 2011;106:124-130
5. Anaesth Intensive Care. 2005;33:719-725
6. Br J Anaesth. 2012;108:1006-1010
7. Br J Anaesth. 2008;101:549-556
8. Reg Anesth Pain Med. 2010;35:529-534
9. Anesth Analg. 2011;113:951-1005
10. Shanghai Med J. 2009;32:34-36
11. Reg Anesth Pain Med. 2011;36:17-20
12. Reg Anesth Pain Med. 2012;37:495-501
13. Anaesthesiology. 2010; 112:374-1381
14. Br J Anaesth. 2012;Nov 29
15. Worldviews Evid Based Nurs. 2004;1(3):176-184
16. BMJ. 2011;18:343
Funding: Department of Anesthesia, Sunnybrook Health Sciences Centre
Personal conflicts of interest disclosure: Nothing to disclose
A164
THE EFFECT OF EPINEPHRINE USE ON ULTRASOUND GUIDED UPPER EXTREMITY BLOCKS:
A META-ANALYSIS
C.G. Samuelson, O. Willett, S. Arulkumar, V. Koyyalamudi
Anesthesiology, Louisiana State University, Shreveport Health System, Shreveport, LA, USA
Introduction: The use of ultrasound is quickly becoming the gold standard for regional anesthesia(1).
Studies show that upper-extremity blocks are associated with an increased incidence of nerve
injury(2). Currently, equipoise exists regarding the need/safety of epinephrine in upper-extremity
blocks(3). The goal of this study was:
1. To review the current literature on the use of epinephrine in ultrasound-guided blocks of the upper
extremity.
2. To use meta-analysis to compare the effectiveness and complication rate of studies using
epinephrine (EPI+), to those not (EPI-)
Material and methods: A literature search was conducted on the use of ultrasound-guided blocks of
the upper extremity using PubMed, Ovid and Cochrane databases. Inclusion criteria stipulated only
prospective/randomized studies of adult patients undergoing ultra-sound guided upper extremity block
for surgery be included; that the studies note whether epinephrine was used; and that the studies
report on the incidence of block failure, vascular puncture, new-onset paresthesia, and use of
supplemental anesthesia.
Random-effects meta-analysis was used to compute effect sizes and compare EPI+/- studies.
Analysis of bias was completed for all study outcomes.
Results: 12 EPI+(990 patients) and 7 EPI-(645 patients) studies were included for analysis. No
studies directly comparing EPI+/EPI- were found. Random-effects meta-analysis revealed an
incidence of block failure of 5%(3.4-7.3) and 3.6%(1.9-6.5) in the EPI+/- studies respectively. While
the incidence of vascular puncture was ~2% among all studies; “comparing” the studies yielded a
4.2%(3.9-4.5,p< 0.001) increase in paresthesia and an 8.5%(8.3-8.7,p< 0.001) increased need for
supplemental anesthesia among the EPI+ studies.
Overall, there appeared to be significant publication bias (p< 0.001), with underreporting of failure rate
(14 “file-drawer” publications), supplementation of anesthesia (8 “file-drawer” publications), vascular
puncture (9 “file-drawer” publications) and paresthesia (6 “file-drawer” publications).
Discussion: Currently, debate exists over the use of epinephrine in peripheral nerve blocks. While no
studies exist directly comparing EPI+/-, the use of epinephrine appears to be associated with a
significantly increased need for anesthetic supplementation. This is counterintuitive, as epinephrine
should extend the duration of neural blockade. The relationship between this and the increase in
paresthesia needs further exploration.
While only higher level-of-evidence studies were included, we detected significant publication bias.
Therefore, our meta-analysis is hindered both by a lack of studies directly comparing EPI+ to EPI-,
and accurate reporting on the efficacy and complications of ultrasound-guided upper extremity blocks.
As such, further study is warranted.
Funding: None
References:
1. Ultrasound in regional anaesthesia. Griffin, J and Nicholls, B. 65, s.l. : Anaesthesia, 2010.
2. Incidence of local anesthetic systemic toxicity and postoperative neurologic symptoms associated
with 12,668 ultrasound-guided nerve blocks: an analysis from a prospective clinical registry. Sites, B
D, et al. 5, s.l. : Reg Anesth Pain Med, 2012, Vol. 37.
3. Effects of epinephrine in local anesthetics onthe central and peripheral nervous systems:
Neurotoxicity and neural blood flow. Neal, Joseph M. s.l. : Regional Anesthesia and Pain Medicine,
2003, Vol. 28, pp. 124-34.
A165
THE MISSING (VIRTUAL) LINK IN REGIONAL ANESTHESIA EDUCATION
J.B. Winchester, G.V. Hickman, E. DeBusk, S.E. Thomas
1
2
3
Regional Anesthesia Fellowship, The Andrews Institute ASC, BLOCKJOCKS Research and
Education Foundation, The Andrews Institute ASC, Gulf Breeze, FL, USA
Introduction: Over the last decade we have seen an increased utilization of regional anesthesia
techniques. Despite the clear evidence supporting the benefits of regional anesthesia to patients and
facilities, physicians often hesitate to adopt these techniques, citing their lack of comfort with their skill
level and lack of guidance in learning new techniques. There are one to two day courses available
which attempt to teach these skills but doctors return home with little follow up support and difficulty
remembering what they practiced on a dummy for a couple hours on a Saturday afternoon. Our
technology advancement called the Docstream Doc-In-The-Box (DITB) bridges the gap for physicians
looking to expand their skills and learn regional anesthesia without having to leave home.
Materials and Methods: DITB is a portable video system designed by Brandon Winchester and
engineered by Clark-Powell. DITB allows a novice user to easily record and live broadcast ultrasoundguided regional anesthesia procedures (demonstration video: http://www.blockjocks.com/tLq32). The
system has several key features. There are two different video cameras: one for a big picture shot
and the second for a close up shot of the hands. A third video input is an ultrasound. The video signal
can be switched on the fly between the two cameras and ultrasound using an iPad app, and also
features a virtual laser pointer which allows structures to be pointed out during the procedure. High
definition video is recorded onto an SD card, and can be live broadcast or videoconferenced onto the
web using a variety of PC software options, including Skype & GoToMeeting. DITB also features a
case which allows it to ship from facility to facility.
Results: At the Andrews Institute ASC, we are using DITB to record and broadcast videos of regional
anesthesia procedures every week, making them available to physicians around the world on
BLOCKJOCKS.COM. We now have >4,000 monthly video views from over 100 countries.
Discussions: DITB offers physicians the opportunity to observe blocks without having to leave their
institution, and also gives universities & industry the opportunity to further assist physician and nurse
education by remote proctoring procedures with our deployable system. Regional anesthesia
programs are being started and expanded upon directly thanks in part to the education afforded by
DITB technology and www.blockjocks.com. Our vision is that DITB play a critical role, not only in the
expansion of regional anesthesia procedures, but medical procedures of all kinds. Furthermore,
studies should be performed in order to validate the DITB-driven improvements in physician skills and
nerve block utilization that we have observed anecdotally in communications with our “virtual
preceptors” from around the world.
This abstract is exempt from IRB approval.
References:
http://journals.lww.com/rapm/Abstract/2010/03001/The_American_Society_of_Regional_Anesthesia_
and.11.aspx
http://www.modernhealthcare.com/article/20120109/MAGAZINE/301099939
http://www.newtek.com/index.php?option=com_content&view=article&id=554
http://www.avnetwork.com/av-technology/0002/is-there-a-doctor-in-the-cloud/90242
www.blockjocks.com
Personal Conflict of Interest:
Winchester- BBraun Medical, Kimberly Clark, Pacira, Sonosite, DOCSTREAM INC, Blockjocks.com
LLC.
Hickman- BBraun Medical, Kimberly Clark, Pacira
Debusk- BBraun Medical
A166
ECONOMIC BURDEN OF UNEXPECTED DAYS OFF INCURRED BY PATIENTS AND THEIR
CAREGIVERS FOLLOWING OUTPATIENT SURGERY
S.M. Owens, A. Manohar, K. Cheung, T. Stierer, C. Wu
Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
Introduction: The economic burden of unexpected days off incurred by patients and their caregivers
following outpatient surgery has not been fully examined. As part of a prospective survey study to
assess the impact of outpatient surgery on recovery of patients and their caregivers in the
postoperative period it was noted that a percentage of respondents required additional, unanticipated
time off from work. Extrapolating that data to the total number of outpatient surgery visits we were
able to calculate the economic burden of those additional days.
Methods: Surveys assessing postoperative recovery were given to patients at six time points: on
postoperative days 0-3, 7 and 30. Surveys assessing the burden of informal caregiving were given to
each patient's primary caregiver at four time points, on postoperative days 1-3 and 7. As part of the
survey patients and caregivers were asked if they needed to take any additional days off from work
than originally scheduled. The data gained from those respondents was then used to assess the cost
of additional days off using both the federal minimum wage and a figure used in the GallupHealthways Well Being Index to calculate the economic cost of absenteeism.
Results: Forty-four adult patients undergoing outpatient surgical procedures and their primary
caregiver were enrolled. We found that 10% of patients needed to take more time off from work than
originally anticipated. Pain was the most frequently cited symptom to prevent the patient from
resuming normal activities. 0.05% of caregivers also needed to take more time off from work than
originally anticipated. Using the minimum wage to calculate the cost of a single 8 hour day of work or
a derived figure used by Gallop representing the cost of a typical employee absentee day and
multiplying that cost by the the number of outpatient procedures performed annually, the cost of these
additional days off was calculated to be between ~$300 million and ~$1.77 billion.
Conclusions: The economic burden of additional time off for patients and their caregivers may top
$1.5 billion. The primary reason cited for that additional time is pain. Currently the cost of medical care
is being very closely scrutinized, and anesthesiologists as acute pain specialists in the perioperative
period are uniquely positioned to reduce the very significant economic burden our findings unveil.
A167
POSTOPERATIVE PAIN AND ANALGESIA REQUIREMENTS FOLLOWING ARTHROSCOPIC HIP
SURGERY: A RETROSPECTIVE CHART REVIEW
E. Yap, M. Behrends, P. Aleshi
Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, USA
Introduction: Arthroscopic hip surgery is becoming increasingly popular to diagnose and treat interior
joint pathology. These surgeries are commonly done in the outpatient setting with many patients
being discharged the day of surgery. However, in spite of the minimally invasive nature of these
procedures, some patients appear to suffer a considerable amount of pain. Subsequently, timely
discharge of these patients can become challenging due to the need for more aggressive acute pain
therapy and for the management of analgesia related side effects such as sedation and nausea.
The purpose of this hypothesis generating retrospective chart review is to assess the acute outcome
of patients undergoing arthroscopic hip surgery, and to identify subgroups of patients at risk to
experience increased pain requiring more aggressive treatment. Patients at high risk for increased
postoperative pain may benefit from pre- or intraoperatively performed regional anesthesia techniques
to reduce postoperative pain, postoperative analgesia requirements, and decrease the length of stay
in the post-anesthesia care unit (PACU). Such preemptive anesthetic and analgesic management of
selected patients undergoing arthroscopic hip surgery could help improve patient satisfaction and
facilitate early discharge.
Material and methods: Review of the surgical and anesthetic records of 100 patients that underwent
arthroscopic hip surgery at a University outpatient orthopedic center from June 2010 through April
2012 was conducted. Demographics, duration of surgery and PACU stay, intraoperative opiate
administration, post-operative visual analog scale (VAS) pain scores, postoperative analgesia
requirements, and postoperative nausea and vomiting (PONV) were reviewed. Opioid doses were
converted into their morphine equivalents to allow comparison.
Results: Average surgery time was 59±22 minutes. Intra-operative opiate administration averaged
16±7 mg morphine equivalents. In the PACU the highest recorded VAS pain score was on average
5.9±2.5, resulting in mean post-operative opiate requirements of 14±10 mg morphine equivalents.
PONV was treated in 10 patients. Average duration of PACU stay was 124±48 minutes.
Linear regression analysis demonstrated that higher VAS pain scores in the PACU were associated
with longer surgery duration (p = 0.103) and an osteotomy performed during surgery (p = 0.033).
There was no correlation between age, sex, or intraoperative opioid administration and postoperative
VAS pain scores. Patients with higher VAS pain scores in the PACU had highly significant increased
PACU opiate requirements (p < 0.0001) and longer PACU stays (p = 0.0008).
Discussion: Patients undergoing arthroscopic hip surgery may expect these minimally invasive
procedures to elicit minimal pain. However, the present chart review demonstrates that these
surgeries may result in a significant amount of postoperative discomfort leading to increased
postoperative analgesia requirements and subsequently prolonged PACU stays. The use of regional
anesthesia in patients undergoing arthroscopic hip surgery is not well established; however, regional
anesthesia techniques could be advantageous for these patients, especially in cases of longer
duration and cases including an osteotomy.
Reference:
YaDeau JT, Tedore T, et al. Lumbar plexus blockade reduces pain after hip arthroscopy: a
prospective randomized controlled trial. Anesthesia and Analgesia 2012; 115(4):968-72
Funding disclosure: Nothing to disclose.
Personal conflicts of interest disclosure: Nothing to disclose.
A168
PHENTOLAMINE HASTENS RECOVERY OF SENSATION AFTER NERVE BLOCK IN RODENTS
M. Young, S. Wang, J. Mao
Department of Anesthesiology, Critical Care, and Pain Medicine, Massachusetts General Hospital,
Boston, MA, USA
Introduction: Prolonged regional block can be associated with complications such as delay of
transfer of care and patient dissatisfaction. Dental literature has demonstrated that phentolamine
reduces the duration of soft-tissue numbness. We hypothesized that phentolamine would
pharmacologically hasten reversal of peripheral regional anesthesia.
Materials and methods: We examined the effect of phentolamine on recovery of sensation after
sciatic nerve block in a rodent model. IRB approval for use of these animals was obtained. We utilized
hte radiant heat light beam of a plantar analgesia meter and observed time to foot withdrawal. Five
rats were placed in raised, transparent enclosures, and the heat light beam was focused on the
plantar hind paw in an area innervated by the sciatic nerve. We measured the time to hind paw
withdrawal up to a maximum of twenty seconds. This test was then performed on the opposite hind
paw and repeated again on both limbs. The reaction latencies obtained formed the baseline reaction
times.
The rats were then lightly anesthetized with 1% enflurane to facilitate landmark-based sciatic nerve
block. On the first experimental day, injections were delivered to the right limb. For each rat, the limb
was infiltrated in the area of the sciatic nerve with 0.1mL of 2% lidocaine with epinephrine.
Subsequent reaction latencies were collected. The rats were then re-anesthetized and given either
0.1mL of 0.9% saline (control group) or 100mcg/0.1mL phentolamine (experimental group) at the
previously injected area. Reaction latencies were again recorded at 60 and 120 minutes. This protocol
was repeated five days later with injections to the left limb providing five control and five experimental
datasets.
Results: At each timepoint , we found the mean reaction latency for each limb and then the difference
in the means between the injected and uninjected limb for both control and experimental groups.
The difference in mean reaction latencies were similar between groups at three of four timepoints:
small at baseline and 120-minute timepoints and increased at the 15 minute timepoint. At 60 minutes,
the difference between limbs was decreased in the phentolamine group yet remained increased in the
saline group (P < 0.05).
Discussion: The data indicate that phentolamine can speed the recovery of sensation to heat
stimulus after sciatic nerve block with lidocaine and epinephrine in rats. In the saline group,
withdrawal latency difference was sustained 45 minutes after nerve block (60 minute timepoint) but
already resolved in the phentolamine group.
We postulate that phentolamine´s alpha-receptor blockade property may promote clearance of local
anesthetic. The clinical effect might be more pronounced after local anesthesia complemented with
epinephrine.
We believe this is the first study to show that a pharmacologic agent can hasten recovery from
peripheral nerve blockade. Previous reports have shown that duration of neuraxial blockade can be
shortened with crystaolloid epidural washout and intrathecal lavage. In dental literature, phentolamine
reduces the duration of soft-tissue numbness.
In conclusion, phentolamine hastens the return of sensory function following sciatic nerve block with
lidocaine and epinephrine in rats.
A169
REDUCTION OF ISOLATED HIP DISLOCATIN WITH KETAMINE
1
2
3
4
5
5
F. Akyildiz , H. Turgut , S. Ozyurek , O. Ersen , S. Ekinci , S. Bilgic
1
2
Orthopaedics, Malatya Military Hospital, Malatya, Orthopaedics, Siirt Military Hospial, Siirt,
4
Orthopaedics, Aksaz Military Hospital, Mugla, Orthopaedics, Maresal Cakmak Military Hospital,
5
Erzurum, Orthopaedics, Gulhane Military Medical Academy, Ankara, Turkey
3
Introduction: Traumatic hip dislocatons are orthopaedic emergecies occured after high energy
traumas and can accompanied by fractures of pelvis, acetabulum, femoral head, patella or femoral,
obturatuar nerve lesions and posterior cruciate ligament ruptures. Traumatic hip dislocations should
be reducted as soon as posibble.
Case report: A 26 years old male admitted to our emergency department with the complaint of left hip
pain, limitation of range of motion and limping after tractor accident. His left hip was in adduction,
flexion and internal rotation and there were no other systemic findings. Neurovascularexamination
was normal. Initial radiological evaluation was made with AP pelvic graphy and dislocation without
fracture found and for early reduction no advance radiological test was done. 40 mg. Ketamine (0.6
mg./kg) IV administered and after 2 minutes reduction manuever longitudinal traction, internal rotation
and adduction force with flxed knee was applied and reduction was achieved in 30 seconds. After
reduction position of extremity in hip extansion and external rotation was secured and controlled by
AP pelvis x-ray and computed tomography. After reduction no fractures or neurovascular deficit was
seen. After first week sitting in bed and isometric exercises, in second week mobilization without
weightbearing allowed. On 8th week full weight-bearing allowed.
At follow up visit on the 12th month of injury full range of motion of hip was found and avascular
necrosis of femoral head did not observed on control MRI.
Discussion: After traumatic hip dislocations vital functions must evaluated first. Because it is %95
related with other systemic injuries. Isolated hip dislocation without fracture is rare (1).
Reduction must be done as soon as possible to avoid avascular nerosis of femoral head.for low
complication rate some authors suggests reduction in 12 hours (2), while some suggests reduction in
6 hours (3). Closed reduction of hip fracture-dslocations are contraindicated. In this case isolated hip
dislocation reducted using potent analgesic effectof ketamine.
References:
1.Gogus A, Akpinar S, Unal M, Sonmez B, Hamzaoglu A. Kalça kırıklı çıkığı (pipkin tip-IV) ile beraber
görülen travmatik aort kapak rüptürü Ulus Travma Acil Cerrahi Derg 2001 (7):1; 66-69
2. Herman C. Epslein: "Posterior Iracture-dislocalion of the hip" J. Bone and Joint Surg. Vo . 56-A, No
6, 1974.
3. Dreinhöfer KE, Schwarzkopf SR, Haas NP, Tscherne H. Isolated traumatic dislocation of the hip.
Long-term results in 50 patients. J Bone Joint Surg [Br] 1994;76:6-12.
A170
PERIPHERAL NERVE FIELD STIMULATION TO TREAT POST-HERNIORRHAPHY PAIN
SYNDROME
R. Alsaigh, G. Novak
Department of Anesthesiology & Pain Medicine, St. Elizabeth's Medical Center. Tufts University,
Boston, MA, USA
Introduction: Post-herniorrhaphy pain syndrome is not uncommon. Fifteen -30% of patients will
develop pain post hernia repair. We present a patient with persistent left inguinal pain following an
open left inguinal hernia repair for 7 months.
Case report: A 44 year old male patient status-post left inguinal hernia repair in April 2012,
complicated by persistent post-surgical pain. Patient described his pain as 8/10 on VAS, sharp, with
pins and needles over the incision and occasionally radiating down the left scrotal area. His pain was
severe enough to interrupt his sleep during night. Patient was referred to us after he failed
conservative management. He had wound infiltration with local anesthetic, provided him with one day
relief. Followed by left sided TAP block which gave him one and a half weeks of pain relief. A
discussion was made with the patient about peripheral nerve field stimulation, and he agreed to it.
After obtaining clearance from the psychology service we proceeded with the trial. In our pain clinic,
we brought the patient to the procedure room, placed him in supine position; his left inguinal area was
prepped and draped with standard sterile technique. Using a 14 G Tuohey epidural needle the
electrical lead was placed in the subcutaneous tissue just below the scar. It was connected to the
pulse generator and tested.The patient felt tingling over his usual pain site. Our patient had a five day
trial. He reported (tremendous) improvement in his pain 75 -80 %. His pain score decreased to 3/10.
In November 2012, our patient underwent permanent placement of peripheral nerve field stimulation
implant.
Discussion: Post- herniorrhaphy pain syndrome is a common problem, Fifteen -30% following
elective inguinal hernia repair. In most of the cases the cause is unknown. Management usually starts
with conservative medical treatment (NSAID, anticonvulsant, antidepressant), Surgery (scar revision,
release of nerve entrapment), interventional nerve blocks (TAP block), and Physical therapy (TENS
unit). For patients who fail these measures, either spinal cord stimulation or peripheral nerve field
stimulation can be effective and offering these patients a trial should be considered.
[Intraoperative PNS implant]
[PNFS Leads and pulse genetrator ]
References:
1) post-operative Inguinodynia from hernia surgery
By Jeffrey B. Mazin, MD, FACS. Practical pain management, April 2010
2) Genitofemoral and Ilioinguinal neuralgia after laparascopic versus open inguinal herniorrhaphy
Narouze, S.N.1; Zakhary, E.2; Basali, A.1 2002 Fall A28
3) Classifying post-herniorrhaphy pain syndromes following elective inguinal hernia repair.
Loos MJ, Roumen RM, Scheltinga MR.
Department of Surgery, Máxima Medical Centre, Veldhoven, The Netherlands. [email protected]
4) Neuromodulation. 2012 Jun 1. doi: 10.1111/j.1525-1403.2012.00463.x.
Combined Spinal Cord and Peripheral Nerve Field Stimulation for Persistent Post-Herniorrhaphy Pain.
Lepski G, Vahedi P, Tatagiba MS, Morgalla M.
Department of Neurosurgery, Eberhard Karls University, Tübingen, Germany.
5) Neuromodulation. 2000 Aug;3(3):155-7. doi: 10.1046/j.1525-1403.2000.00155.x.
Spinal cord stimulation for post-herniorrhaphy pain.
Elias M.
The Pain Clinic, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Patient is aware, and agrees for the case report publication.
A171
REGIONAL BLOCKADE FOR TOTAL SHOULDER REPLACEMENT IN A PATIENT WITH SEVERE
LUNG PATHOLOGY, OBSTRUCTIVE SLEEP APNEA, AND CARCINOID SYNDROME
E. Baker, N.C.K. Lam, M. Charles, C. Arndt, T.R. Petersen
Department of Anesthesiology and Critical Care Medicine, University of New Mexico, Albuquerque,
NM, USA
A 73 y/o woman was scheduled for total shoulder arthroplasty. Her past medical history was
significant for obesity, severe mixed obstructive and restrictive lung disease requiring home oxygen,
biochemically active metastatic rectal carcinoid syndrome, peripheral neuropathy of the lower
extremities, and severe degenerative osteoarthritis of the left shoulder with severely restricted motion.
The patient had also been on multiple medications for chronic arthritic and neuropathic pain. There
was concern that managing the patient's pain with a regional block placed at the interscalene level
could compromise the patient's lung function and result in respiratory distress even with volumes as
1
low as 5 ml. There was also concern that avoiding regional anesthesia altogether and controlling her
pain using systemic medications only could also pose a problem given her chronic opioid use and her
obstructive sleep apnea. The anesthesia team decided that the best approach would be a regional
anesthesia technique that could be used for intraoperative and postoperative pain control but could
reliably avoid involvement of the phrenic nerve.
Using a 80 mm 22 G echogenic stimulating needle with ultrasound guidance, the posterior cord of the
brachial plexus was identified by visualization and confirmed by stimulation resulting in deltoid muscle
2
movement using a transverse infraclavicular approach. 8 ml of 0.5% ropivacaine with
dexamethasone was injected into the area around the posterior cord and good spread around the
posterior cord was noted. After this injection was completed the patient was placed in a seated
position, and a suprascapular nerve block was placed under ultrasound guidance at the level of the
3
spine of the scapula using 12 ml of 0.5% ropivacaine with dexamethasone.
[SUPRASCAPULAR NERVE BLOCK]
The patient was again placed supine, and immediately said that she had no pain in her shoulder for
the first time in many years. Pulmonary ultrasound did not demonstrate paralysis of hemidiaphragm.
She proceeded to the operating room and was placed under general anesthesia for her comfort. An
arterial line was placed given the patient's history of carcinoid. The patient tolerated the procedure
well with no reaction to incision and no exacerbation of her carcinoid symptoms. The patient was
extubated uneventfully at the end of the operation and had good pain control. The local anesthetic
provided pain relief for approximately 18 hours and she was able to be transitioned onto oral agents
without difficulty. The patient was discharged from the hospital on POD #2 with no complications.
Follow up has been uneventful.
1. Riazi S, et al. Effect of local anesthetic volume (20 mL vs 5 mL) on the efficacy and respiratory
consequences of ultrasound-guided interscalene brachial plexus block. Br J Anaesth. 2008;101:549556
2. Nicholas Lam, et al. Transverse infraclavicular approach to the brachial plexus - MEAC. ASRA
2012; Abstract 109
3. Harmon D, et al. Ultrasound-guided suprascapular nerve block technique. Pain Physician.
2007;10(6):743-746.
A172
ANESTHETIC MANAGEMENT USING REGIONAL ANESTHESIA IN A PATIENT WITH TYPE 1
VON WILLEBRAND DISEASE UNDERGOING OPEN SHOULDER SURGERY
G. Geng-Ramos, E. Shepard, V. Bansal
Anesthesiology, University of Maryland, Baltimore, MD, USA
A 21 year old male with congenital Type I von Willebrand Disease was scheduled to undergo a repeat
left shoulder Latarjet Procedure. The patient was diagnosed with von Willebrand Disease as a young
child, with baseline laboratory studies of von Willebrand antigen of 11% (NR: 60-150%), coagulation
factor VIII 17% (NR: 50-150%), ristocetin cofactor activity of 10% (NR: 70-132%), and normal vWF
mulitmers, with poor response to DDAVP. The patient's surgical history involved a previous Laterjet
procedure performed under general anesthesia. His post-operative course was notable for inadequate
pain control, poor physical therapy compliance and the need for further surgeries.
Anesthetic plan for this procedure was general anesthesia combined with a continuous Interscalene
catheter for post-operative pain management. One hour prior to the procedure, the patient received
Humate-P 50units/kg (3,650 units of ristocetin cofactor activity). An interscalene catheter was placed
under ultrasound guidance preoperatively without complication. General anesthesia was induced, and
surgery begun. Intraoperatively the patient was noted to have an increased amount of generalized
bleeding. The patient received an additional dose of 3,650 units of Humate-P, with significant
improvement of intraporative bleeding . The remainder of the surgical intervention was uneventful,
and transfusion of blood products was not required. Total surgical time was 182 minutes, EBL 600 ml.
Postoperatively, the patient received repeat does of Humate-P at 12 hours and 24 hours postoperatively, as advised by his hematologist. He described good pain control with an continuous
interscalene catheter infusion of ropivicaine and a back-up PCA. He began rehabilitation therapy on
post-op day 1 with adequate pain control (Pre-therapy pain score 0/10, post-therapy pain score 4/10).
The patient was discharged home with his interscalene catheter and an ambulatory pain pump
containing 0.2% ropivacaine. The catheter was removed at home without complications.
Although bleeding diathesis is a relative contraindication to regional anesthesia, with appropriate perioperative management of our patient's coagulopathy, we believed the benefits of interscalene
catheter for our patient outweighed the risks. Despite having to redose Humate-P, proper placement
using ultrasound guidance and meticulous securing of the catheter ensured a successful
postoperative coarse in our patient.
A173
MULTIMODAL APPROACH FOR MANAGING ACUTE POST-TRAUMATIC PAIN IN A HEROIN
ADDICT
G.F. Barbosa-Hernandez, V. Masri, J. Eismon, B. Astley, M. Bassett
Anesthesia, MetroHealth Medical Center, Cleveland, OH, USA
Introduction: Patients with pain refractory to opioid use that require surgery present a challenge.
Refractory cases prompt the use of NMDA receptor antagonists and off-label use of medications with
analgesic side effects.
Case: A 25yoM was brought to the ED after a motor vehicle accident. Injuries included bilateral open
ankle fractures, left tibia fracture, and a right shoulder fracture/dislocation. He was neurovascularly
intact. Laboratory workup was normal, except for the toxicology screen which was positive for recent
opioid and alcohol use. The pt admitted to drinking 6-8 beers daily and abusing heroin (1 gram daily)
for the past 5 years.
His right shoulder was reduced, and he then went to the OR for emergent bilateral ankle ORIF and
external fixator placement to his left tibial plateau fracture. Following a rapid sequence induction, his
anesthesia was maintained with isoflurane, remifentanil infusion, and multiple boluses of fentanyl and
hydromorphone. He had an uneventful PACU recovery and was admitted to a regular floor.
Later that day, the acute pain service was consulted due to uncontrolled pain (10/10) and agitation.
We intiated IV lorazepam via CIWA protocol, started a ketamine infusion (5mg/hr), increased his IV
PCA hydromorphone to 1mg every 6 minutes (demand only), began pregabalin (50mg orally TID),
and began memantine (5mg orally BID). The following day the patient's pain was 7/10. We increased
pregabalin (100mg orally TID), began methadone (10mg orally QID) and dronabinol (2.5mg orally
BID), and later in the evening discontinued ketamine. On POD 2, the patient's pain had improved
significantly (2/10). On POD 3, we stopped dronabinol and PCA hydromorphone and started oral
hydromorphone (4mg q3h PRN). Following discontinuation of the IV hydromorphone, the patient's
pain worsened. Over several days, we increased his methadone dose (15mg orally TID and 30mg at
nighttime). On POD 6, he was discharged with his pain controlled to an acute rehabilitation facility. A
week later, he underwent definitive fixation of his left tibia plateau fracture. He was compliant with his
regimen at the rehab facility and there were no issues in managing his pain following surgery.
Conclusions: Opioid tolerant patients have hyperalgesia and require aggressive treatment
perioperatively. Methadone's activity at adrenergic receptors provides analgesic effects not influenced
by opioid tolerance. NMDA receptor antagonism by methadone blocks morphine tolerance and opioid
induced hyperalgesia. Ketamine's NMDA receptor antagonism can block the development of opioid
tolerance and opioid-induced hyperalgesia and reverse both phenomena. Complementary use of
other NMDA receptor antagonists, like memantine, has been suggested to decrease opioid tolerance
in patients with opioid resistant pain[1]. Dronabinol has been advocated in the setting of chronic opioid
therapy for chronic non-cancer pain, as an adjuvant, with some encouraging results related to
satisfaction with therapy; however, no opioid sparing properties have been found[2].
References:
1. Grande, L.A., Ultra-low dose ketamine and memantine treatment for pain in an opioid-tolerant
oncology patient. Anesth Analg, 2008. 107(4): p. 1380-3.
2. Narang, S., Efficacy of dronabinol as an adjuvant treatment for chronic pain patients on opioid
therapy. J Pain, 2008. 9(3): p. 254-64.
A174
SUCCESSFUL MANAGEMENT OF INTRACTABLE BRACHIAL PLEXOPATHY PAIN WITH
CONTINUOUS LOCAL ANESTHETIC INFUSION VIA AN IMPLANTED INTERSCALENE
CATHETER TUNNELED TO A PERCUTANEOUS ACCESS PORT
D.B. Boyce, K.V. Vlassakov, P.L. Pelletier, S. Narang
Anesthesiology, Perioperative and Pain Medicine, The Brigham and Women's Hospital/Harvard
Medical School, Boston, MA, USA
1
Introduction: Pain from neoplastic plexopathy can be challenging to treat . We report successful
management of intractable brachial plexopathy pain with continuous local anesthetic infusion via an
implanted interscalene catheter connected to a percutaneous access port, placed under ultrasound
guidance.
Case: A 35 year-old woman presented with severe upper extremity neuropathic pain caused by a
metastatic synovial sarcoma invading her right brachial plexus. Extensive treatment since diagnosis 9
years prior included multiple surgical resections, radiotherapy, and chemotherapy. The apical tumor
had been resected through a median sternotomy, removing the right first rib and medial clavicle.
Subsequent paravertebral and epidural spread, required cervical laminectomies and hardware
fusions, precluding epidural analgesic techniques.
At presentation, the pain was severe and uncontrolled with high-dose analgesic therapy, including IV
hydromorphone over 215 mg/day, IV ketamine 0.2 mg/kg/hour, gabapentin 900 mg PO TID, lidocaine
5% patch/day, rendering the patient into a semi-conscious state.
Examination revealed right lower neck and upper chest deformity by tumor and scarring. A temporary
interscalene brachial plexus catheter was placed under ultrasound guidance after a 22 mL
ropivacaine 0.5% bolus, followed by bupivacaine 0.125% infusion (Fig.1).
[Figure 1]
Within 10 minutes, profound analgesia ensued and a technically challenging ultrasound-guided
periarterial injection (80 mg methylprednisolone, 8 mL 0.5% ropivacaine) was performed empirically at
the brachial plexus cords for possible extended analgesia. As the pain decreased and the analgesics
weaned, she became more alert and ambulatory. Six days later, a permanent interscalene catheter
was placed under ultrasound guidance via anterior approach, tunneled subcutaneously and attached
to an implanted Port-a-Cath™ for long-term infusion (Fig.2).
[Figure 2]
Pain and analgesic requirement continued to decrease. Functional status, quality of life, and
therapeutic options improved - she went home with a portable infusion carrying case, managed by
visiting nurses, and was able to resume chemotherapy. She remained on a stable dose for six weeks
without tachyphylaxis. During a neutropenic episode, a dehiscence and leak at the Port-a-Cath™
incision site required removal of the system. An intrathecal pump was then implanted.
Conclusions: Neuropathic pain originating from complex compressive and infiltrative neoplastic
plexopathy may be treated effectively by continuous local anesthetic plexus infusion via an implanted
catheter with an access port. This technique is reversible and preferable to destructive procedures
such as cordotomy. It may also increase therapeutic options not otherwise tolerable, such as plexus
steroid injections or chemotherapy.
Discussion: There have been surprisingly few reports of successful treatment of malignant
neuropathic pain with continuous peripheral nerve blocks since 1994 when the first case of
2
continuous interscalene analgesia for a patient with Pancoast tumor was published . Curiously, both
then, and in our case, peripheral nerve blockade was considered only after neuraxial modalities were
excluded - an interesting, yet persistent preference, possibly based on medical culture, pain
stereotypes and predominant practice.
References:
1. Kori et al. Brachial plexus lesions in patients with cancer. Neurology 1981;31:45-50
2. Sato et al. Continuous Interscalene Block for Cancer Pain. Regional Anesthesia 1994;19(1):73-74
A175
DISCOVERY OF DVT DURING PLACEMENT OF FEMORAL NERVE CATHETER FOR TOTAL
KNEE ARTHROPLASTY
E.R. Briggs
Vanderbilt University Medical Center, Nashville, TN, USA
Introduction: Practitioners of regional anesthesia may often find themselves in pressured situations
to get procedures done quickly. It is very easy to develop tunnel vision and not observe surrounding
anatomy as critically as we should. I would like to present an instance where being observant of
surrounding anatomy positively affected a patient´s care.
The patient was a 39 year old female with rheumatoid arthritis and history of deep venous thrombosis
(DVT) secondary to Antiphospholipid Antibody Syndrome with a rare, acquired prothrombin antibody.
She was scheduled for revision of a right total knee arthroplasty (TKA), following infection of her
previous replacement. The anesthetic plan included preoperative femoral nerve catheter and sciatic
nerve block. A general anesthetic was planned per the patient's request.
Ultrasound was utilized for femoral nerve block/catheter placement. During the procedure, it was
noted that the common femoral vein was somewhat resistant to compression. Further evaluation of
the vein using color doppler revealed flow in only a small portion of the vessel, consistent with
possible thrombus. This patient's hypercoagulable state, immobility of the affected limb, and
conversion of Coumadin to low molecular weight heparin (LMWH) preceding surgery, placed her at
very high risk for development of DVT. The procedure was aborted and, following discussion with the
surgeon, surgery was postponed pending a formal venous ultrasound study. The study revealed subocclusive thrombus in the common femoral vein but extensive occlusive thrombus in the femoral,
popliteal, and calf veins. Surgery was cancelled and the patient was scheduled for immediate follow
up with her hematologist.
The patient's LMWH dose was increased to 100mg BID. Six weeks later, a follow up venous doppler
examination revealed recanalization of the occlusive thrombus. The patient then underwent an
uneventful general anesthetic for TKA revision that included a femoral nerve catheter and sciatic
nerve block.
Discussion: This incidental finding from using ultrasound to perform regional anesthesia, had a
positive and significant effect on the management of this patient. Without evidence of the DVT seen
while placing the femoral nerve catheter, this patient would have gone to the OR for TKA and could
have very likely suffered a significant embolic event leading to significant morbidity or mortality.
Examination of the literature reveals multiple descriptions of non-neural pathology noted during
ultrasound guided nerve blocks. At least two reports exist describing a DVT found while performing
1,2
ultrasound guided femoral nerve blocks. There are likely other similar instances that have gone
either unreported or unnoticed. If the anesthesiologist performing or observing the procedure is
rushed or focuses solely on the neural anatomy, these clinically significant findings are simply missed.
Sites, et al ask, as practitioners of ultrasound regional anesthesia, should we be expected or required
2
to investigate surrounding and relevant structures. I propose we remain observant and avoid tunnel
vision.
References:
1. Sutin KM, et al. Deep venous thrombosis revealed during ultrasound-guided femoral nerve block.
Br J Anaesth 2005;94:247-8.
2. Sites BD, et al. On the edge of the ultrasound screen: regional anesthesiologists diagnosing
nonneural pathology. Reg Anesth Pain Med 2006;31:555-62
A176
UNEXPECTED DIFFICULT PAIN CONTROL FOLLOWING BILATERAL HAND DE-GLOVING
SPLIT-THICKNESS SKIN GRAFT SURGERY
M. Charles, M. Billstrand
Anesthesiology and Critical Care Medicine, University of New Mexico, Albuquerque, NM, USA
Introduction: A 32-year old male presented to our Outpatient Surgery Center for split-thickness skingrafting (STSG) and revision for bilateral hand de-gloving injuries he had sustained during a workrelated incident several months before. His wounds included right first and second digit amputations,
incomplete amputations of the remaining fingers of the right hand and left hand de-gloving injury
requiring a groin flap. The patient was otherwise healthy with his only prior surgery being his previous
finger amputations and groin flap. On the day of his revision/STSG surgery, the patient was evaluated
and an anesthetic plan including a pre-operative supraclavicular nerve block for the left hand and
general anesthesia was formulated. The right side did not need a nerve block as it was insensate.
Surgery was uncomplicated and the patient arrived in the PACU extubated and responsive. Shortly
after arrival, the patient started to experience “10/10” pain in his left groin, the site of the skin graft
harvest, not relieved by repeated doses of IV morphine and fentanyl administered by the PACU
nurse. Upon evaluation by the staff anesthesiologist, it was determined that an ultrasound guided
ilioinguinal/iliohypogastric nerve block would be performed. The nerves were identified and 15ml of
0.5% ropivicaine was injected in the plane between the transversus abdominis muscle and the
internal oblique muscle. Within 5 minutes, the patient's pain was significantly decreased and he was
discharged home later that afternoon.
Discussion: As this case illustrates, the actual injury site being grafted does not necessarily
constitute the most painful area after split-thickness skin grafting has been performed. In fact, the
“donor site” (area from which the graft is taken) will many times be much more prone to post-operative
pain. This can pose a challenge to the anesthesiologist in planning for pain control, especially if a
regional technique is being utilized. One method that we have found to be effective is pre-operative
peripheral nerve block for the area to be harvested with subsequent delineation of the area that has
been anesthetized. This requires close communication with the surgeon to establish the planned
harvest site, coordination in order to perform to the nerve block ahead of time in the pre-operative
area, and time enough for the nerve block to establish itself so borders can be demarcated.
Alternatively, as occurred in this case, a post-operative “rescue” nerve block can be performed in the
PACU if IV or oral analgesics are not covering the pain. This method, while initially faster (i.e. does
not require additional pre-operative time to perform and confirm adequacy of the nerve block) has the
drawback of subjecting the patient to undue discomfort. Rescue blocks have the additional
disadvantage of oftentimes being performed under non-ideal circumstances, that is, on patients who
have difficulty maintaining a position due to pain or target sites that are partially or completely covered
by post-operative dressings or appliances.
A177
CASE OF A “STUCK” EPIDURAL CATHETER IN THE LATERAL RECESS
S. Cheng, T. Halazynski, M. Jacoby
Yale Anesthesiology, Yale University School of Medicine, New Haven, CT, USA
Epidural analgesia performed for labor management has a good safety profile. However,
complications may include inability to remove catheter following delivery, usually due to knot formation
or coiling.
20yo female G2P0010, 36+5wks, 5'3”, 72.6kg, without lumbar spine pathology, in active labor,
requested epidural for analgesia. Catheter placement occurred uneventfully: patient sitting, standard
ASA monitors, skin sterilely prepped and draped. Loss of resistance occurred at 6cm, catheter
threaded, and secured at 9cm to skin. Test dose negative and patient reported pain relief within
10min of dosing.
60min later patient reported increased pain with no relief despite local boluses. Decision made to
repeat epidural, but catheter removal was met with resistance. Removal with patient sitting, arched
back, flexed waist, arc of shoulders right then left while traction was applied proved ineffective. Saline
injection also failed. Catheter marking at the skin was now 6cm (Figure1). Patient continued to labor
and second epidural was placed in vertebral space above initial catheter without complication. Both
catheters were secured and taped to patient's skin.
Following delivery, second epidural catheter was easily removed. Trapped catheter was still unable to
remove despite repeated attempts using methods described above. Neurosurgery consulted and CT
scan showed catheter tip terminating in right L1-L2 lateral recess with acute turn of 75 degrees after
traversing the L1-L2 spinous processes (Figure2). With patient in right lateral decubitus position,
flexion/extending of the waist, arching of pelvis left and right, and saline injection permitted catheter
removal with tip intact.
1
Various maneuvers/positioning have been described to assist in removal of trapped catheters.
Suggestions include: 1) avoid multiple attempts of extraction in same position; 2) cease traction with
evidence of excessive catheter stretch; 3) discontinue if catheter begins to stretch; reattempt several
hours later; 4) flexion/extension can be combined with lateral decubitus patient positioning; 5) removal
2-5
in extreme flexion/extension; 6) CT scan to identify etiology; and 7) injection of sterile saline. Case
is notable for aberrant location of where catheter was trapped and atypical patient position of
noninvasive technique for successful catheter removal.
Figure 1: Top catheter removed from patient. Bottom catheter for comparison (~7cm stretch).
Figure 2: CTscan of epidural catheter migrating into the right facet joint.
[Figure 1]
[Figure 2]
References:
1. Kendall M, Nader A, Maniker R, McCarthy R. Removal of a knotted stimulating femoral nerve
catheter using a saline bolus injection. Local Reg Anesth. 2010;3:31-4.
2. Mitra R, Fleischmann K. Management of the sheared epidural catheter: is surgical extraction really
necessary? J Clin Anesth. 2007; 19:310-4.
3. Lala P, Langer V, Rai A, Singh R. A rare complication of epidural anesthesia a case report with
brief review of literature. Indian J Anaesth. 2011;55:629-30.
4. Renehan E, Peterson R, Penning J, Rosaeg O, Chow D. Visualization of a looped and knotted
epidural catheter with a guidewire. Can J Anaesth. 2000;47:329-33.
5. Chang P, Hu J, Lin Y, Tsou M. Butterfly-like knotting of a lumber epidural catheter. Acta
Anaesthesiol Taiwan. 2010;48:45-8.
A178
THE ROLE OF LONG TERM OUTPATIENT CONTINUOUS PERIPHERAL NERVE CATHETERS IN
THE TREATMENT OF NON-HEALING WOUNDS
T. Pontinen, C. Chiang, W. Ennis, A. Rakic
1
2
Anesthesiology, Vascular Surgery, University of Illinois, Chicago, IL, USA
Introduction:
Non-healing wounds and the pain associated with them can be difficult to manage. Traditionally,
medications have been the mainstay of treatment, but continuous peripheral nerve catheters (CPNCs)
are proving to be an effective alternative. For the last two years, we have treated multiple patients
suffering from a variety of non-healing wounds successfully using CPNCs and here we present three
cases exemplifying this success.
Material and Methods/Results:
The first case is a 52 year old female with diabetes mellitus and peripheral vascular disease and a
seven year history of non-healing foot ulcers. For 6.5 years, her pain was treated unsuccessfully with
high dose opioids, limiting her visit compliance, and ability to function independently. In 5/2011, we
placed an infra-gluteal sciatic CPNC with continuous infusion (2 mL/hr 0.2% ropivicaine) and patient
controlled boluses (10 mL every 90 min), maintaining it from 5/2011 - 1/2012. During her weekly
debridement visits, her catheter was bolused with 2% Lidocaine, providing surgical analgesia in a
clinical setting. Over these eight months, her compliance with wound care visits, independence, and
quality of life vastly improved, and her ulcers healed completely.
The second case involves a healthy 43 year old man who developed a large wound on his left medial
knee after falling from his bike. A distal femoral CPNC was placed initially for post operative pain
control following an incision and debridement/wound VAC placement, but was kept in over the
following 4.5 months of rehab, dressing changes, and skin grafts. His catheter was maintained in the
same manner as the first case. Throughout this time, he never required any narcotics and his wound
completely healed.
The final case involves an 81 year old man with metastatic prostate cancer and chronic venous
insufficiency who suffered from poorly treated lower extremity chronic wounds for over a year. An
infra-gluteal sciatic CPNC was placed and over the following two months, his narcotic requirements
decreased and ulcers shrank. Although he elected to remove his catheter after a superficial wound
infection before his ulcers completely healed, his current quality of life and narcotic requirements are
much better than prior to the placement.
Discussion:
CPNCs provide highly effective analgesia and facilitate patient compliance while avoiding the
problems associated with opioid use. In addition to pain control, CPNCs have the theoretical benefits
of increased tissue perfusion and oxygenation through sympathectomy induced vasodilation (1), antiinflammatory effects (2), and may attenuate resulting pain sequelae, including phantom limb
syndrome (if an amputation is required) (3). Given the favorable risk / benefit of regional anesthetic
techniques, its theoretical advantages, its ease of use in the outpatient setting, and our ever-growing
population of patients with non-healing wounds, we not only advocate further research in this
promising field, but also the increased use of these catheters in clinical practice.
References:
1. Bhattarai BK, Rahman TR, et al. J Nepal Med Assoc. 2006 Jul-Sep;45(163):295-9.
2. Swanton BJ, Shorten GD. Int Anesthesiol Clin. 2003 Winter;41(1):1-19.
3. Battista B, D´Addabbo M, et al. Anesthesia and Analgesia. 2010 November 111 (5)
A179
REGIONAL ANESTHESIA FOR A PATIENT WITH SEVERE PULMONARY DISEASE
D. Chirumamilla, O. Viktorsdottir, K. Fikry, K. Fleischmann
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital,
Harvard Medical School, Boston, MA, USA
Introduction: We describe the anesthetic management of a 60-year-old female with complex medical
history and significant pulmonary comorbidity requiring urgent surgical debridement of an infected
elbow S/P total elbow arthroplasty.
History: The patient is a 60-year-old female who presented to our institution with an infected right
elbow prothesis requiring urgent surgical debridement. She had a history of severe COPD (FEV1
22%)requiring 2-3L home O2 and multiple episodes of hypercarbic respiratory failure requiring
prolonged intubation and a previous tracheostomy, which was later reversed. In 2009 she required
intubation for iatrogenic pneumothorax after nerve block.
The patient had a history of ischemic cardiomyopathy, multifocal atrial tachycardia, recent atrial
fibrillation with a rapid ventricular response, anxiety, hepatitis B and C infection, chronic alcohol
dependence and substance abuse.
After an extensive evaluation, we decided that avoiding general anesthesia and any significant
sedation would be optimal, given her history of prolonged intubations and mechanical ventilation after
general anesthetics and her history of substance abuse.
Plan and procedure: The decision was made to proceed with regional anesthesia using an axillary
block as the primary anesthetic for the procedure. We felt that this would be the best and safest
option for our patient in order to avoid risks associated with more proximal brachial plexus blocks, that
is risks of pneumothorax and hemidiaphragmatic paralysis that would have been detrimental for this
patient.
After applying standard ASA monitors the patient was positioned for axillary block placement. Under
sterile conditions, we used an ultrasound probe to visualize the axillary artery and the cords of the
brachial plexus in cross section. Using ultrasonic guidance a 22 gauge 50mm insulated panjunk
needle was advanced until the cords of the brachial plexus were approximated and a total of 18ml of
1.5% mepivicaine and 8 ml of 0.5% bupivicaine with 1:400000 epinephrine was injected in 5 ml
aliquots incrementally with no resistance after negative aspiration. The patient experienced no
paresthesias and tolerated the procedure well without complications. Surgical anesthesia was
achieved in 5 minutes with the patient requiring no supplemental anesthesia or sedation
intraoperatively.
Discussion: By performing an axillary block under ultrasound guidance we were successful in
providing a safe and satisfying anesthetic for this patient with high peri-operative risk of pulmonary
morbidity and mortality. By avoiding general anesthesia and keeping our patient spontaneously
breathing intraoperatively we minimized the risk of hypercarbic respiratory failure and prolonged
postoperative hospital stay. By administrating long acting local anesthetic we achieved good
postoperative analgesia and reduced postoperative opioid requirement in this medically challenging
patient.
References:
· Sanchez M, Malhotra N, Lin L., Semin Cardiothorac Vasc Anesth. 2012 Mar;16(1):59-64., End-stage
pulmonary disease and brachial plexus regional anesthesia: their implications on perioperative
pulmonary function.
· Urmey WF, Gloeggler PJ., Reg Anesth. 1993 Jul-Aug;18(4):244-9., Pulmonary function changes
during interscalene brachial plexus block: effects of decreasing local anesthetic injection volume.
A180
DISCREPANCY OF SUBSEQUENT BLOCK SUCCESS RATE IN A PATIENT WITH ADHESIVE
CAPSULITIS
L. Curia, J. Kent
Anesthesiology/ Pain Management, University of Rochester Medical Center, Rochester, NY, USA
Adhesive Capsulitis of the glenohumeral joint can be either primary or secondary to an underlying
condition like diabetes, Thyroid illness and Trauma.Mean age of onset is 55 in males and 52 in
females. The incidence is higher in depression, anxiety, migraine headaches, hypertension, diabetes
and chronic back pain. In secondary capsulitis the adhesions are in the joint with no involvement of
the capsule resulting in a non-functional frozen joint. In the primary form, there is fibroblastic
proliferation of the capsule so the shoulder freezes is in a functional position. There is gradual and
painful restriction of the motion so treatment modalities are directed to improving this.We present a
case of adhesive capsulitis in a patient with injury to the ipsilateral elbow who came for a series of
interscalene blocks for temporary analgesia before aggressive PT.
49 year-old male with a work-related injury to his left elbow with ruptured biceps tendon. He
underwent repair of this and required further manipulation under anesthesia. He had resultant
compressive ulnar neuropathy at the elbow as well as carpal tunnel syndrome and a claw-type
deformity. He required further elbow lysis of adhesions for which he had an infraclavicular block that
failed and was repeated in the supraclavicular approach with good results.He then developed left
frozen shoulder and scapular winging. He participated in physical therapy with poor outcomes given
his underlying pain. We were contacted by the surgical team to possibly use nerve blocks to facilitate
PT and improve his ROM.We performed an unsuccessful ultrasound-guided interscalene block with a
22G 2-inch long needle via an in-plane view. 20cc of 0.125% Bupivacaine were injected We
proceeded to do another left interscalene nerve block without pain relief or motor/sensory changes
either.He had further visits and a second practitioner performed the blocks. The second time was
successful with duration over 24 hours using 30ml of 0.25% bupivacaine. The third block was
successful but there was ulnar sparing. The fourth time there was a new block failure and it had to be
repeated with success. Regardless of the type of capsulitis, there is a gradual restriction of the ROM
of the joint with resultant pain. The treatment goal is pain reduction with preservation of shoulder
mobility. PT is one of the main pillars of these therapies and needs concomitant adequate analgesia
to be achievedMultiple cases have been described about the usefulness of regional anesthesia in
assisting with exercise tolerability. The idea is to provide sensory block with the least motor inhibition.
The use of ultrasound in regional anesthesia has grown significantly over the past few decades and it
allows us to target our injection sites as well as to observe for local anesthetic spread.
It was our experience in this case that the spread patterns would change from one block to another
and so would the effectiveness and duration of the block. We believe the brachial plexus, just like the
glenohumeral joint, might have microscopic collagen deposits that could explain the difficult and
erratic access to the sheath.
A181
THREATING CHRONIC SHOULDER PAIN WITH ULTRASOUND-GUIDED PULSED
RADIOFREQUENCY LESIONING OF THE SUPRASCAPULAR NERVE: CASE REPORTS
1
2
1
S. Deniz , S. Bilgic , T. Purtuloglu , A. Atim
1
1
2
Anesthesiology, GMMA Haydarpasa Training Hospital, Ankara, Orthopedics, GMMA Haydarpasa
3
4
Training Hospital, Istanbul, Gulhane Military Medical Academy, Anesthesiology, GMMA, Ankara,
Turkey
İntroduction: Threating chronic shoulder pain with pulsed mode radiofrequency (PRF) lesioning
attractive as a non- destructive method is favored. We present a method for PRF using ultrasound
guidance in patients with chronic shoulder pain in this reports.
Case reports: Two males and a female patients with 86,63 and 70-year-old had chronic shoulder
pain. Diagnostic suprascapular block was performed with the method described by Wertheim and
Rovenstine. We got approval from patient with pain relief in 1-3 days for PRF threapy. 5 cm SMK
needle with 4 mm active tip was inserted postero- anterior direction using an out-of-plane or in-plane.
The suprascapular artery was first identified with color Doppler imaging. Suprascapular nerve was
seen near the suprascapular artery. Location of suprascapular nerve was corrected by sensory and
motor stimulation. PRF lesioning was carried out once for 300 seconds. After the procedure patient's
pain score was reduced from 8,7,8 out of 10, to 3,1,2 out of 10 in a visual analog scale (VAS). All
patients were satisfied with treatment and their shoulder movements improved.
Conclusion-results: PRF treatment using ultrasound guidance can reduce the risks of harming not
only suprascapular nerve but also surrounding vascular structure. Also ultrasound helps the operator
manipulate and advance the needle to a more precise position.
A182
LIPOSOMAL BUPIVICAINE FOR ANALGESIA FOLLOWING MULTIPLE RIB FRACTURES: A
CASE REPORT
E. Draper, B.A. Pearce-Smith, J.E. Chelly
Division of Acute Interventional Perioperative Pain, UPMC - Presbyterian Shadyside Hospital,
Pittsburgh, PA, USA
Introduction: Regional anesthesia has been demonstrated to provide optimum pain management in
the patient with multiple rib fractures, because it preserves respiratory function, avoids tracheal
intubation, and decreases the occurrence of pneumonia. This case report examines the role that
liposomal bupivacaine may play.
Materials and methods: The Acute Interventional Perioperative Pain Service (AIPPS) was consulted
regarding an 86 year old male, status post motor vehicle accident with multiple injuries including acute
fractures of 8 right ribs and 6 left ribs. At the time of consultation the patient was post admission day
11, on a therapeutic heparin infusion for the treatment of a recent pulmonary embolism, and ventilator
dependent with a tracheostomy. He had failed spontaneous breathing trials (SBT) on the ventilator
due to rib fracture induced chest pain. Following patient assessment, and discussion with the trauma
team, single shot injections at multiple paravertebral levels with liposomal bupivicaine was proposed
to minimize the risk of bleeding associated by the combination of thrombolytic therapy and peripheral
nerve block. The blocks were performed after the heparin infusion was stopped for 4 hours. The 20
mL vial of 1.3% liposomal bupivicaine suspension (266 mg) was diluted with preservative-free normal
sterile saline to 30 mL and used for the bilateral multiple single shot paravertebral nerve blocks,
performed under ultrasound guidance in the left lateral decubitus position.
Results: The next morning the patient had improved dramatically, denying chest pain via written
communication for the first time. He ultimately succumbed to deconditioning after 7 hours of SBT, and
was returned to controlled ventilation. The following day the same scenario occurred. Since there was
a concern for CHF, it was decided not to repeat the blocks. Eventually the patient was successfully
weaned to a trach mask, and discharged to an outside care facility.
Discussion: This case illustrates the relative complexity of patients with multiple rib fractures and
therefore the relative value of prolonged single shot blocks to preserve respiratory function. Our
standard protocol for the management of pain following multiple rib fractures utilizes continuous
paravertebral blocks. Following the performance of these continuous blocks patients receive
thromboprophylaxis. In this case, where this patient received ongoing therapeutic anticoagulation,
single shot blocks with a long lasting local anesthetic preparation were performed. Further research
with liposomal bupivicaine is required to determine the relative clinical indication of this preparation in
trauma patients.
References:
Ho AM, Karmakar MK, Critchley LA. Acute pain management of patients with multiple rib fractured
ribs: a focus on regional techniques. Current Opinion in Critical Care 2011, 17:323-327.
Mohta M, Verma P, Saxena A, et al. Prospective, Randomized Comparison of Continuous Thoracic
Epidural and Thoracic Paravertebral Infusion in Patients With Unilateral Multiple Fractured Ribs - A
Pilot Study. J Trauma 2009;66:1096-1101.
A183
A CASE OF ACUTE TAKOTSUBOS CARDIOMYOPATHY ASSOCIATED WITH SPINAL BLOCK
T. Egan
Department of Anaesthesiology, Saint Michaels Hospital, Toronto, ON, Canada
Tackotsubos Cardiomyopathy is defined as a disease exhibiting acute left ventricular apical
ballooning of unknown cause. The left ventricle takes on the shape of a “takosubo” (Japanese
octopus trap). In the majority of patients there is resolution of the apical akinesis within a month. A
dynamic obstruction of the left ventricular outflow tract is also observed(1)
I would like to report the case of a 90 year old female scheduled for a right total hip replacement for
osteoarthritis. She had a past history of hypertension, dyslipidaemia, rectal cancer, DVT, and
rheumatic fever.
Preoperative echocardiogram had demonstrated no significant valvular involvement and normal LV
and RV. ECG demonstrated sinus rhythm with LVH by voltage criteria. Her medications included
Metoprolol, Enalapril and Warfarin. She was to be bridged with LMWH
ECG , NIBP, pulse oximetry, 20 guage IV cannula and spinal anaesthetic were established (2.5ml of
0.5% isobaric bupivacaine, 25 guage Whitacre needle). Blood pressure fell from 130/70 to 80/40 with
ECG demonstrating no untoward changes. 50 micrograms of phenylephrine was administered with
BP coming up to 110/60. The patient was transferred from the block room to the OR. . The patient
was conversant and happy during this time. ECG monitoring was re-established prior to transfer onto
the OR table and ST elevation was noted in lead II and III. NIPB was 120/40 and block to ice was T6
bilaterally. The patient was completely comfortable and demonstrated no symptoms of heart failure. A
12 lead ECG demonstrated 2mm ST elevation in V3, V4 and V5 consistent with an anterolateral
myocardial infarction.
Cardiology attended the OR, Heparin 4000IU intravenously, aspirin 160mg PO plus clopidogrel
300mg PO were given. Coronary angiogram demonstrated no culprit lesion. Left ventricular
angiography was performed which demonstrated akinesia of the anterolateral,apical and inferoapical
segments (grade 3 left ventricle). The basal segment was contracting normally. Echocardiogram
demonstrated an ejection fraction of 43% with systolic anterior wall motion. Five days later, prior to
discharge, there was restoration of function with ejection fraction up to 73%.Incidentally there were no
signs of spinal haematoma.
The underlying etiology of takotsubos is thought to be based on an exaggerated sympathetic
stimulation (2). This patient denied any feeling of anxiety and her outward appearance was consistent
with this. This presentation is unusual in that this patient had no symptoms of chest pain or dyspnea,
or evidence of emotional or physical stress. Left ventricular ejection fraction is reported to resolve
within a mean time of 7-37 days (2) and in this patient it had resolved by day five. One must conclude
the haemodynamic stress of the spinal block must have had some role in the dynamic presentation of
this stress cardiomyopathy.
References:
1.Kawai, Sachio, Akira Kitabatake, and Hitonobu Tomoike. "Guidelines for diagnosis of takotsubo
(ampulla) cardiomyopathy." Circulation journal: official journal of the Japanese Circulation Society
71.6 (2007): 990.
2.Pilgrim, Thomas M., and Thomas R. Wyss. "Takotsubo cardiomyopathy or transient left ventricular
apical ballooning syndrome: a systematic review." International journal of cardiology 124.3 (2008):
283-292.
A184
SEIZURE POST BRACHIAL PLEXUS BLOCK IN PATIENT WITH REMOTE HISTORY OF
SEIZURES WITH NON TOXIC DOSE OF LOCAL ANAESTHETIC
T. Egan
Department of Anesthesiology, Saint Michaels Hospital, Toronto, ON, Canada
I would like to report a case of local anaesthetic toxicity in a patient with a pre-existing convulsive
disorder with a non toxic dose of local anaesthetic. There has been a previous case report of a patient
receiving brachial plexus block with dosing within recommended limits who developed neurological
symptoms of local anaesthetic toxicity with a childhood history of febrile convulsions (1). There have
also been 4 case reports of LA toxicity encountered with patients with pre-exisitng neurological
conditions, particularly cerebral palsy (2).
A 38 year old female weighing 62 KG presented for a right thumb metacarpal fusion. She had a past
medical history of rheumatoid arthirits, temperomandibular sugery and a remote history of simple
partial seizures. She requested a regional technique. Supraclavicular block was undertaken using
ultrasound and nerve stimulation. The patient was premedicated with 2 MG of midazolam. Triceps
stimulation was observed at 0.5mA and an adequate spread of LA was observed on ultrasound in
what appeared to be normal anatomy. A total dose of Ropivicaine 100mg plus Lidocaine 200mg was
injected in a fractioned injection with regular aspiration and no suggestion of a intravascular injection.
This dose did not exceed recommended maximal local anaesthetic dose for her weight (3)
Approximately one minute post injection the patient had a tonic clonic seizure. Resuscitation as per
ASRA guidelines was initiated with 100ml intralipid 20% administered followed by 0.25mg/kg per hour
infusion, Simultaneously the patient was intubated and sedated with midazolam. No heamodynamic
instability was observed, the patient awoke around 30 minutes later, seizures had terminated and
patient was orientated and uneventfully extubated. She was reviewed by a staff neurologist and
discharged the same day.
This case poses the question that in the absence of a precipitating cause such as intravascular
injection or toxic doses of Local anaesthetic did this patient history of seizures predispose to
neurotoxicity of local anaesthetic. The ASRA guidelines on Local Anaesthetic toxicity emphasise the
primacy of preventing LAST as the most effective intervention and advise dose reduction in those with
IHD, cardiac conduction abnormalities and those at the extremes of ages, but not those with a history
of seizures, although heightened awareness of LAST is recommended in those with neurological
disorders (4)
1. Satsumae, T., et al. "Convulsions after ropivacaine 300 mg for brachial plexus block." British journal
of anaesthesia 101.6 (2008): 860-862.
2. Di Gregorio, Guido, et al. "Clinical presentation of local anesthetic systemic toxicity: a review of
published cases, 1979 to 2009." Regional anesthesia and pain medicine 35.2 (2010): 181
3. Miller, Ronald D., Lars I. Eriksson, and Lee A. Fleisher. "Miller's anesthesia".
4. Neal, Joseph M., et al. "ASRA practice advisory on local anesthetic systemic toxicity." Regional
anesthesia and pain medicine 35.2 (2010): 152.
A185
SURAL NERVE PAIN: SIMILAR RESPONSE BETWEEN PULSED RF AND METHYLENE BLUE
CHEMONEUROLYSIS
S. EL Ahdab, B. Mitchell, M. Eckmann
Anesthesiology/Pain, UTHSCSA, San Antonio, TX, USA
Background: Radiofrequency Neurolysis ( RF and pulsed RF) and chemoneurolysis ( methylene blue
and dextrose) have been used successfully in treating a multitude of several chronic pathologies
especially for nociceptive and neuropathic pain. Pulsed RF has been recommended more for
peripheral nerve pain as it has less risk of deafferentation potential.
Objectives: To report on similarity in pain relief from Pulsed RF vs methylene blue chemoneurolysis.
Methods: The case described here is that of a 46 year old female who fractured her right fifth toe and
since then had been having pain along the right sural nerve distribution. She had multiple successful
sural nerves blocks with a 1:1 solution of 2% lidocaine and 0.5 % Marcaine. The patient then
underwent a methylene blue chemoneurolysis. This was followed 5 months later with pulsed
Radiofrequency ablation.
Results: The patient reported complete relief for 2 weeks from both methylene blue as well as Pulsed
RF. She was back to her baseline pain score 6 weeks after both procedures.
Limitations: This report describes a single case report.
1
Conclusions: A previous case report has showed successful pain relief from sural nerve pulsed RF.
Our case follows showing no clear difference in efficiency between sural nerve pulsed radiofrequency
vs sural nerve methylene blue chemoneurolysis.
1-Pulsed radiofrequency of the sural nerve for the treatment of chronic ankle pain. Pain Physician.
2011 May-Jun;14(3):301-4. Todorov L.
A186
LUMBAR SYMPATHETIC BLOCK SUCCESSFULLY TREATS CHEMOTHERAPY INDUCED
BILATERAL LOWER EXTREMITY NEUROPATHIC PAIN IN A PATIENT WITH MULTIPLE
MYELOMA
M.F. Esposito, M. Anitescu
Anesthesia and Critical Care, University of Chicago, Chicago, IL, USA
Chemotherapy-induced peripheral neuropathy is a major side effect of many chemotherapeutic
1
agents. CIPN can be extremely painful and disabling, causing significant functional debility and
2
decreasing quality of life. It is not entirely clear how chemotherapeutic agents cause neuropathic pain
yet with increasing numbers of patients experiencing excellent outcomes and prolonged survival due
3
to chemotherapy, long-term pain management is becoming a challenging aspect of treatment. We
present a 57-year-old female with multiple myeloma who developed BLE pain after chemotherapy
whose pain was improved with lumbar sympathetic blocks.
A 57-year-old female with MM developed severe BLE CIPN (burning, tingling numbness, 10/10 pain)
after effective lenalidomide and Bortezomib treatment. Increasing doses of opioids (methadone
120mg daily, hydromorphone, hydrocodone), gabapentin, and amitriptyline were ineffective: she
continued to have severe pain, poor sleep architecture, poor appetite, an inability to work, and
drastically decreased physical activity secondary to pain. Physical exam demonstrated diminished
sensation over the dorsal and plantar aspects of the feet. The patient underwent caudal epidural
steroid injection with minimal pain relief. The patient returned for fluoroscopy-guided bilateral LSB at
the level of L3. Each block consisted of 40mg triamcinolone, 5mL 0.5% bupivacaine, and 5mL 2%
lidocaine. The patient experienced profound pain relief (pain score2/10). The patient returned two
weeks later for repeat LSB with similar success. The relief lasted for two months until chemotherapy
was restarted at which point her pain worsened. She again underwent bilateral LSB with excellent
analgesia. Furthermore, the patient's opioid requirements were drastically reduced to methadone
30mg daily and occasional acetaminophen with codeine.
Although it is not completely understood how chemotherapeutic agents result in chronic pain, it has
been demonstrated that these agents cause structural damage to peripheral nerves that result in
1,2
aberrant somatosensory processing of the peripheral and central nervous systems.
Both
3
lenalidomide and Bortezomib have been implicated. The exact mechanism underlying the peripheral
3
neuropathy is unknown. Cells of the peripheral nervous system are vulnerable as primary sensory
and autonomic neurons are contained in ganglia that lie outside the blood-brain barrier and are
supplied by fenestrated wall capillaries allowing free passage of molecules between the circulation
and the ECF in the ganglia. Neuropathic pain is often multifactorial and the SNS may play a role in the
4
maintenance of certain neuropathic pain states. The underlying mechanism for sympathetically
mediated pain is unclear; however, it has been suggested that the presence of an abnormal coupling
5
between the sympathetic and the somatosensory nervous system may be responsible for SMP. This
coupling may be in the peripheral nerve or the DRG due to neurogenic inflammation following nerve
5
lesion. Sympathetic blocks targeting SMP to treat neuropathic pain syndromes (e.g., CRPS, PHN)
6
have been described. However, our unique case utilized LSB as part of a regimen to treat CIPN. It is
possible that LSB for CIPN are able to reduce the SMP component at the DRG and interrupt the cycle
of uncontrolled pain, allowing the appropriate healing process to commence.
1. WolfS.EuroJCancer2008;44:1507-1515.
2. WindebankAJ.CurrentOpinioninNeurology1999;12(5):565-71.
3. WindebankAJ.JPeriphNervSys2008;13:27-46.
4. TranKM.AnesthAnalg2000;90:1396-1401.
5. Krumova.RegAnesthPainMed2011;36(6): 560-7.
6. DayM.PainPract2008;8: 98-109.
A187
ELBOW SURGERY PERFORMED UNDER SUPRACLAVICULAR BLOCK ON A PATIENT WITH
HEREDITARY NEUROPATHY WITH LIABILITY TO PRESSURE PALSIES (HNPP)
J. Galey, E. Shepard
1
2
Anesthesiology, University of Maryland School of Medicine, Anesthesiology, Kernan Orthopaedics
and Rehabilitation, Baltimore, MD, USA
Presentation: Our patient was a 25yo M with a history of Hereditary Neuropathy with Liability to
Pressure Palsies (HNPP), a rare genetic neuromuscular disorder that renders a patient easily
susceptible to nerve injury from pressure, stretch, or repetitive use. The patient fell from a roof at work
and sustained a Terrible Triad Injury to the right upper extremity. He had undergone several operative
procedures to stabilize the elbow since the injury, but his elbow function remained limited. All of the
previous surgeries had been performed under general anesthesia (GA) with an IV PCA for post
operative pain control. Due to the potential risk of nerve injury with regional anesthesia (RA),
peripheral nerve blockade has traditionally been considered a relative contraindication in HNPP
patients. Unfortunately, this patient had significant issues with pain control following his prior
surgeries, and the pain limited his ability to participate in therapy, resulting in a suboptimal surgical
outcome.
Outcome: After much discussion regarding risks and benefits of RA, we agreed to perform a
supraclavicular block for the primary surgical anesthetic. The goal was for the patient to be able to
participate in early physical therapy. A supraclavicular catheter was successfully placed under
ultrasound guidance and bolused with 30ml of 0.5% ropivacaine. The patient was sedated with
propofol during the case. Upon arrival to the PACU, the patient was started on a low dose perineural
infusion of 0.2% ropivacaine at 10ml/hour. The patient frequently reported pain scores of 2/10 and
had full return of motor function the evening of surgery. The patient fully participated in physical
therapy on post-operative day one, and was discharged home with an ambulatory pain pump infusing
0.2% ropivacaine. The patient was very satisfied with his postoperative analgesic therapy and no
residual motor or sensory deficits were noted. He reported excellent elbow function upon follow-up.
HNPP - Background info: Hereditary Neuropathy with liability to Pressure Palsies (HNPP) is an
autosomal dominant progressive neurologic disorder causing the individual to be highly susceptible to
nerve injury resulting from pressure, stretch or repetitive use. Following injury, the nerve demyelinates
leading to sensory, motor, or combined neurologic deficit. The palsy can range from mild and nonlimiting to severe and long lasting. The peroneal nerve, ulnar nerve, radial nerve, and median nerve
are most commonly affected. This disorder can be seen in 16 of 100,000 people in the general
population.
Discussion: Little information exists in the literature with regard to regional anesthesia in patients
with HNPP. Many experts advise avoiding nerve blocks in patients with risk factors for neurological
injury. This case is unusual and interesting in that the patient had a rare genetic neurologic disorder
with direct anesthetic implications. Although relatively contraindicated, it was felt that the risk-benefit
ratio favored regional anesthesia, as the patient´s prior surgeries had limited success due to poor
post-operative pain control. Careful placement of this block, with slow injections under ultrasound
guidance resulted in an excellent outcome without complication.
A188
SUBDURAL SPREAD OF LOCAL ANESTHETIC DURING LUMBAR PLEXUS BLOCK: A CASE
FOR THE TEST DOSE
J. Ghassemi, N. Stites-Hallett, P. Aleshi, M. Braehler
Anesthesiology and Perioperative Care, University of California, San Francisco, San Francisco, CA,
USA
Introduction: Numerous case reports describe unintentional subdural injection of local anesthetic
during subarachnoid or epidural anesthesia. Inadvertent placement of local anesthetic in the subdural
potential space may also occur during performance of lumbar plexus blockade. Clinical presentation
may go unrecognized or be attributed to other causes. A high clinical suspicion in addition to testdose utilization could allow for early detection and prevent further consequences.
Case: Lumbar plexus blockade with catheter placement is a commonly performed technique for intraand post-operative analgesia during hip arthroplasty at our institution. We present a case of a 56
year-old female with osteoarthritis of her left hip and two prior hemiarthroplasties who was scheduled
for a revision surgery of her left hip. She consented to preoperative placement of a left lumbar plexus
injection and catheter for intra- and post-operative analgesia.
After right lateral decubitus positioning, sterile preparation and draping, the patient received Fentanyl
100 mcg and Midazolam 2 mg IV with calming effect. The patient received skin infiltration with
lidocaine 2% (3 mL). We used a 10-cm 18-gauge nerve-stimulating needle to elicit an isolated
quadriceps muscle twitch down to 0.5 mA at a needle depth of 8.5 cm. After negative aspiration, we
injected a test dose of 3 mL of 1.5% lidocaine with 1:200,000 epinephrine. Within 2.5 minutes the
patient had loss of sensation to touch, cold, and pin prick and within 5 minutes, she was unable to
move her left lower extremity and became hypotensive with a systolic blood pressure of 90 mmHg.
During this time, the needle was removed and catheter placement was aborted. The patient was
adequately resuscitated with fluids and vasopressors. Within 15 minutes her block peaked to C7
bilaterally yet she retained 5/5 motor strength in her right lower extremity; within one hour she had
return of motor and sensory function in her left lower extremity.
Discussion: While the possibility for inadvertent epidural or intrathecal injection exists when
performing lumbar plexus blockade, we believe that the likelihood of a subdural injection in our case is
strong given the disproportionate extent of sensory block with relation to the total amount of local
anesthetic administered as a test dose.
Consequences of inadvertent subdural injection may vary in their clinical severity. By administering a
test dose prior to injection and catheter placement, we were able to avoid potentially catastrophic
complications from this lumbar plexus block. Our case of presumed subdural spread of local
anesthetic while performing a lumbar plexus block serves to raise awareness of the critical
complications of this technique and suggest early recognition of subdural injection by using a test
dose.
References:
1. Agarwal D, Mohta M, Tyagi A, Sethi AK. Subdural Block and the Anaesthetist.
Anaesthesia and Intensive Care, 2010;38:1.
2. Boezaart A. Is There Something Else We Should Know to Prevent Complications: Microanatomy of
the Peripheral Nervous System Revisited, And Its Implications for Paravertebral Blocks. Lecture:
OAPRS, October 2008.
A189
ULTRASOUND-GUIDED PARAVERTEBRAL BLOCK IN A MORBIDLY OBESE PATIENT WITH
ANTERIOR MEDIASTINAL MASS, OBSTRUCTIVE SLEEP APNEA, AND CHRONIC PAIN
REQUIRING SURGERY: ACHIEVING SAFETY AND COMFORT
J. Ghassemi, L. Lin
Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, USA
Introduction: The anesthetic management of patients with an anterior mediastinal mass remains a
challenging and perilous endeavor to anesthesiologists. These tumors can cause severe airway and
vascular compromise, effects that may be exacerbated in the comorbid patient. Administering general
anesthesia to such patients increases the risk of cardiovascular and respiratory collapse. Anesthetic
approaches—including regional anesthesia—that avoid general anesthesia for patients with an
anterior mediastinal mass requiring surgery may reduce this risk and improve outcomes. We present
a case of a medically challenging patient with a symptomatic, large anterior mediastinal mass who
received a single-shot thoracic paravertebral block and light sedation for scheduled surgery.
Case: A 47-year old female with progressive dyspnea and chest radiograph findings of a large leftsided pleural effusion, rightward cardiac shift, and a large right upper lobe consolidation consistent
with an anterior mediastinal mass—suspicious for lymphoma—was scheduled for an incisional left
axillary lymph node biopsy. Preoperative chest CT confirmed the large pleural effusion causing
complete left lower lobe and partial left upper lobe collapse; it also demonstrated a large mass
infiltrating the mediastinum extending superiorly, with obstruction involving both the airways and major
vasculature (complete right jugular vein obstruction and left subclavian and brachiocephalic vein
narrowing). Complicating the patient's clinical status was a history of morbid obesity (BMI=34),
obstructive sleep apnea, and chronic pain from genital herpes simplex virus. Given a concern for
potential hemodynamic and respiratory complications in this comorbid patient with a symptomatic
anterior mediastinal mass, general anesthesia was regarded as a high risk option. Instead, we
decided to proceed with a regional anesthetic block and minimal systemic sedation.
A left-sided, T1 single-shot paravertebral block was performed with real-time ultrasound guidance
using a transverse view and an in-plane approach. The patient was seated for the procedure,
standard ASA monitors were placed, and supplemental oxygen via nasal cannula provided. Local
anesthesia was achieved via infiltration of subcutaneous tissues with 1% mepivacaine. After
confirming needle-tip visualization in the paravertebral space, 10-mL of 0.5% ropivacaine was injected
without complications. The patient tolerated the procedure and subsequent surgery well, and required
only midazolam 1 mg and fentanyl 25 mcg intravenously for light intraoperative sedation.
Discussion: Fatal airway obstruction or cardiovascular collapse in patients with a large anterior
mediastinal mass under general anesthesia is well documented, a risk that is exacerbated with the
above comorbidities. While general anesthesia is sometimes unavoidable, a regional technique when
feasible elegantly avoids those dangers.
When presented with a comorbid patient with an anterior mediastinal mass and the heightened risks
that a general anesthetic or deep sedation would entail, we opted to perform a regional anesthetic
technique—a left-sided, T1 single-shot paravertebral block—to achieve effective anesthesia while
optimizing patient safety.
References:
1. Slinger P, Karsli C. Management of the patient with a large anterior mediastinal mass: recurring
myths. Curr Opin Anaesthesiol. 2007;20:1-3.
2. Gothard JWW. Anesthetic Considerations for Patients with Anterior Mediastinal Masses.
Anesthesiology Clin. 2008; 26:305-314.
[Ultrasound-guided Paravertebral Block]
A190
HYDRODISCECTOMY - A PERCUTANEOUS TECHNIQUE TO TREAT RADICULAR PAIN FROM
CONTAINED LATERAL LUMBAR DISC HERNIATIONS
1
1
S. Gianoukos , R. Pitts , F.J. Gerges
1,2
1
Department of Anesthesiology and Pain Medicine, Pain Management Center, Department of
Anesthesiology and Pain Medicine, Steward St. Elizabeth's Medical Center, Brighton,
2
3
Anesthesiology, Tufts University School of Medicine, Boston, Pain Medicine Fellowship, St.
4
Elizabeth's Medical Center, St. Elizabeth's Pain Management Center, St. Elizabeth's Medical Center,
Brighton, MA, USA
Percutaneous disc decompression (PDD) techniques are increasingly being offered to patients with
contained disc herniations. They offer an alternative to minimally invasive spine surgery.
Hydrodiscectomy (Hydrocision, North Billerica, MA, USA), specifically, employs a high-pressure water
jet to simultaneously resect and remove nuclear material, while preserving the surrounding tissue. We
present a patient who benefited greatly from this procedure with complete resolution of his radicular
symptoms. Patient gave consent for this publication.
Case report: A 43-year-old otherwise healthy male, presented to our Pain clinic with low back pain
radiating to his left posterior thigh, calf and sole of the foot. His pain was shooting, 5/10 on VAS scale,
worse with coughing, walking or bending. He had undergone conservative therapy with NSAIDs,
heat/ice, and physical therapy for three months, with minimal relief. On physical examination, he had
a positive left Straight Leg Raise. Lumbar MRI showed L5-S1 moderate left lateral disc protrusion
compressing the left L5 nerve root (Fig 1). He underwent four Lumbar Epidural Steroid Injections over
six months with 80% reduction of his symptoms for only 3-4 weeks following each injection. At this
point, he underwent a left-sided L5-S1 Hydrodiscectomy (Fig 2). At his 2 weeks follow-up, his back
pain was 1/10 and the radiating pain to his leg had completely resolved.
[Figure 1-Lateral Left L5-S1 Disc Herniation on MRI]
[Figure 2-Resector Insertion via Perc Cannula]
Discussion: Surgical approaches to disc decompression are accompanied by a number of damaging
sequelae, such as annular incompetence, epidural fibrosis, and formation of scar tissue around the
nerve. In addition, data have shown that the recurrence rate of lumbar disc herniation following
1
Microdiscectomy is as high as 26%.
PDD aim to reduce intradiscal pressure in the nucleus and thereby create space for the contained
herniated disc fragment to retract inwards. As a result, there is a reduction of nerve root compression,
thus less radicular pain.
The goal of Hydrodiscectomy, specifically, includes pulverizing a quantifiable amount of disc material
and removing it via an evacuation tube. Only a 4-mm annulotomy is required, through which 15% of
the nucleus is removed. Advantages include: lack of nerve root manipulation, scar tissue formation,
and epidural fibrosis. It is done under local anesthesia/sedation in an outpatient setting, with the ability
to return to work within one week. A recent report showed 94% short term improvement < 6 Month in
2
lower back and radicular pain . We believe that Hydrodiscectomy bridges the gap between failed
conservative therapy and Microdiscectomy for patients with contained lateral disc herniations causing
unilateral radicular symptoms. However, well-designed, prospective case-controlled trials are needed
to determine its long term efficacy and safety.
References:
1- Carragee EJ, et al. Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment
type and annular competence. J Bone Joint Surg Am. 2003; 85-A(1):102-8.
2- Hardenbrook MA, et al. Clinical Outcomes of Patients Treated with Percutaneous Hydrodiscectomy
for Radiculopathy Secondary to Lumbar Herniated Nucleus Pulposus. The Internet Journal of Spine
Surgery. 2013 Volume 7 Number 1.
A191
REVISION TOTAL SHOULDER ARTHROPLASTY WITH UNRECOGNIZED SUBCLAVIAN
ARTERY ANEURYSM RUPTURE
B. Golbaba, M. Isenhower, S. Clendenen, R. Greengrass
Department of Anesthesiology, Mayo Clinic, Jacksonville, FL, USA
Introduction: Aneurysms of the upper extremity are extremely rare accounting for only 1% of all
[1]
peripheral aneurysms; of these, subclavian aneurysms are the most common . Subclavian
aneurysms and pseudoaneurysms can present with a number of symptoms including hoarse voice,
dysphagia, stridor, extremity numbness/tingling and ischemic signs. Known causes include
[2]
[3,4]
atherosclerosis, thoracic outlet syndrome, and trauma (blunt trauma , IJ cannulation complication ).
Recognition of aneurysmal rupture is essential as it is potentially life and limb threatening with known
[5]
sequelae including nerve compression (brachial plexus , stellate ganglion, recurrent laryngeal),
tracheal compression, thromboembolism, limb ischemia, and life-threatening hemorrhage. We report
a case of ischemic neuropathy secondary to aneurysrmal rupture attributed to motor block associated
with an interscalene catheter.
Case report: A 70 year old female with history of hyperlipidemia, asthma, rheumatoid arthritis, left
breast cancer s/p chemo-radiation, and previous left shoulder arthoplasty complicated by infection
was scheduled for left shoulder arthrotomy with soft tissue debridement and humeral head exchange .
An uncomplicated ultrasound guided interscalene catheter was placed for postoperative analgesia
and dosed with 20 cc of 0.5% ropivacaine . Her intraoperative course was complicated by significant
blood loss and hypotension for which she received blood transfusions and vasopressors. She
remained hypotensive in PACU and a right internal jugular central as well as radial arterial line were
placed.
Lab investigation revealed an acute postoperative coagulopathy with a hematocrit of 23.7, platelet
count 93k and INR of 1.7. She received replacement therapy and her coagulopathy subsided. It was
noted that the patient was complaining of significant pain despite complete motor block. She received
hydromorphone PCA to supplement the local anesthetic interscalene infusion (6c/hr 0.2% ropivicaine
with 6 cc bolus q 60 minutes).
On postoperative day (POD) 1, the patient's arm was noted to be ecchymotic with pitting edema.
Shoulder and arm pain persisted despite a complete motor block.
On POD 2, the patient was noted to have increased arm swelling. CT examination revealed a left
subclavian pseudoanyerusm and hematoma with mass effect which was confirmed with angiography.
Radiology placed a stent graft and her interscalene catheter was removed prior to returning to the OR
for hematoma evacuation.
Discussion: Neurologic injury including brachial plexopathy has been reported secondary to
subclavian pseudoaneurysm. Prompt diagnosis and treatment is crucial to prevent permanent injury.
The ischemic neuropathy observed in our patient was incorrectly attributed to motor block from the
regional catheter however ongoing pain prompted further investigation and revealed the correct
[6]
diagnosis. Studies of ischemic pain secondary to compartment syndrome have also revealed a
breakthrough pattern. Whenever significant pain occurs in the presence of a functional regional
catheter alternative diagnoses such as ischemic neuropathy should be contemplated and
investigated.
Sources:
th
1. Townsend, C. Sabiston Textbook of Surgery. 18 Ed. New York: Saunders; 2007.
2. Serrano, J. Acta Orthopædica Belgica, Vol. 69 - 6 - 2003
3. Modi MP. Indian J Crit Care Med 2007:11;93-5
4. Pastores SM. Am J Crit Care. 1995;4(6):472-5.
5. O´leary MR. Am J Emerg Med. 1990;8(2):129-33.
6. Walker BJ. Reg Anesth Pain Med. 37(4):393-7.
A192
COMBINED SUPERFICIAL CERVICAL PLEXUS AND “PECS BLOCK” FOR PACE MAKER/
AUTOMATIC INTERNAL CARDIAC DEFIBRILLATOR INSERTION
B. Golbaba, C. Robards, C. James
Department of Anesthesiology, Mayo Clinic, Jacksonville, FL, USA
Introduction: Pacemaker(PM) and (AICD) insertion has increasingly become a procedure requiring
the expertise of an anesthesiologist due to the moribund status of the patient population requiring
[1]
these devices . The physiologic changes associated with general anesthesia and sedation with field
local anesthetic may not be tolerated by a large number of these patients. Several regional
techniques for pacemaker insertion have been described in the past but are not commonly used by
[2,3]
most practicing anesthesiologists .
We describe a regional anesthetic method utilizing a superficial cervical plexus (SCP) block combined
with a “Pecs block” to provide surgical anesthesia for a patient with significant cardiac history that
required PM/AICD insertion.
Materials and methods: A 74 year old male with history of coronary artery disease, hypertension,
diabetes mellitus, chronic renal failure and peripheral vascular disease who was admitted for
myocardial infarction was found to have severe left ventricular dysfunction (ejection fraction 18%).
During hospitalization he was placed on an intraaortic balloon pump (IABP) to augment cardiac
output. Following weaning of the IABP, the patient went into flash pulmonary edema requiring
mechanical ventilation. Cardiolgy determined that the patient would benefit from a PM/AICD.
After standard ASA monitors were applied and following cleansing of the left anterior chest wall with
chlorhexidine, a Philips Sparq Ultrasound machine equipped with a linear L12-4 probe was used to
identify the pectoralis major and pectoralis minor muscles. Using a 22 gauge touhy needle, 10 ml of
0.5% ropivacaine was deposited between the pectoralis major and pectoralis minor muscles, similar
[4]
to the technique described by Blanco et al . Following that, we then performed a left sided SCP
block, depositing 10 cc of 0.5% ropivacaine along the posterior border of the sternocleidomastoid at
the level of the C6 vertebrae transverse process down. A total of 50 mcg of IV fentanyl was titrated to
effect for the two block procedures.
Results: The patient underwent the pacer insertion procedure, lasting 200 minutes, comfortably. A
total of 75 mcg of fentanyl was given along with 10 mcg/kg/min of propofol; the patient was able to
respond to command during the procedure at all times. The patient was very comfortable in the
recovery area and well into the following day, requiring essentially no analgesics.
[PEC Block]
Discussion: In this clinical case, we found that the utilization of a SCP in conjunction with a
“Pecsblock" provided surgical anesthesia for PM/AICD insertion thus minimizing anesthesia and the
physiologic perturbations associated with general anesthesia or heavy sedation.
References:
1. Veve I, Melo LF. Anesthesia for Pacemaker Insertion. Seminars in Cardiothoracic and Vascular
Anesthesia. 2000;4(3):138-143.
2. Raza SM, Vasireddy AR, Candido KD, Winnie AP, Masters RW. A complete regional anesthesia
technique for cardiac pacemaker insertion. J Cardiothorac Vasc Anesth. 1991;5(1):54-6.
3. Martin R, Dupuis JY, Tetrault JP. Regional anesthesia for pacemaker insertion. Reg Anesth.
14(2):81-4.
4. Blanco R. The ´pecs block´: a novel technique for providing analgesia after breast surgery.
Anaesthesia. 2011;66(9):847-8.
Funding Disclosure: Nothing to disclose.
Personal Conflicts of Interest Disclosure: Nothing to disclose.
A193
INFRACLAVICULAR NERVE BLOCK IN A PATIENT WITH INCLUSION BODY MYOSITIS
M.C. Grant, E.A. Freck
Johns Hopkins Hospital, Baltimore, MD, USA
Objective: To describe the anesthetic plan and postoperative course of a patient with inclusion body
myositis undergoing outpatient right hand metacarpophalangeal fusion and extensor to flexor tendon
transfer. Regional anesthesia for inclusion body myositis has not been described in the literature.
Case description: Patient MK is a 67 year old female with a five year history of progressive bilateral
lower extremity proximal muscle wasting was well as bilateral wrist flexion and neck flexion weakness.
Progression of symptoms necessitated muscle biopsy. Biopsy confirmed moderately severe, chronic
myopathy with red-rimmed vacuoles consistent with inclusion body myositis. Her medical history was
also significant for psoriatic arthritis, osteoarthritis s/p cervical discectomy and hypertension. Home
medications included dicyclomine, diclofenac, tizanidine and Humira. She further reported occasional
outpatient opioid prescriptions in conjunction with various arthritic flares and minor surgical
interventions. Furthermore, the patient carried a questionable history of asthma which may be
attributed to axial muscle weakness associated with her myositis diagnosis. Focused physical exam
revealed 4/5 strength to wrist flexion bilaterally, markedly decreased grip bilaterally, 4/5 iliopsoas and
ankle flexion/extension bilaterally. Gait was slow and deliberate.
Given worsening fine motor disturbance and poor hand coordination, she was scheduled as an
outpatient for right thumb metacarpophalangeal joint fusion with right index finger extensor to flexor
tendon transfer.
Our anesthetic plan for this patient included the following:
(A) Preoperative single shot infraclavicular block with 30ml 0.25% bupivacaine with 1:200k
epinephrine. The patient's operative arm was abducted 90° with needle insertion site medial & inferior
to the coracoid process. Needling was ultrasound-assisted with an in-plane approach using a high
frequency linear probe. Infraclavicular block permitted us to avoid potential risk of phrenic nerve block
with a supraclavicular approach. Given her muscle weakness incorporated both peripheral and
proximal muscles and the outpatient nature of the surgery, we wanted to avoid any potential for
respiratory compromise. This also provided useful postoperative analgesia to address potential
chronic pain symptoms given multiple opioid adjuncts on an outpatient basis.
(B) Maintenance anesthetic with inhaled fluorinated agent (general anesthesia) with LMA. Given the
length of surgery and precision necessary for the procedure as well as by request of the patient, we
elected to perform general anesthesia. In order to avoid neuromuscular blockers in light her myositis
diagnosis, we utilized LMA placement for airway support.
Postoperatively, the patient did well. She was monitored per our typical institutional outpatient PACU
protocol and discharged home without apparent anesthetic or surgical complication. Her block lasted
approximately 12 hours and she tolerated low dose oral oxycodone thereafter for pain control. Initial
surgical follow-up was encouraging, as within 10 days of her procedure she attained dramatic
improvement in fine motor dexterity in her operative hand.
This case illustrates the anesthetic challenges associated with an outpatient orthopedic procedure on
a patient with both chronic pain and inclusion body myositis. Our strategy carefully addressed the
need for appropriate surgical exposure while limiting known risks associated with our patients unique
medical characteristics.
A194
RECTOSIGMOID RESECTION FOR TUMOR IN A PATIENT WITH DILATED CARDIOMYOPATHY USE OF BILATERAL TRANSVERSUS ABDOMINIS PLANE (TAP) CATHETERS AND PCA FOR
POST-OPERATIVE PAIN MANAGEMENT
J.S. Green, A. Kreitz, B.C.H. Tsui, Edmonton Academy of Regional Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Single-shot transversus abdominis plane (TAP) blocks can reduce morphine
1
requirements in patients undergoing abdominal surgery. In our practice, a multimodal regime utilizing
TAP blocks in combination with other analgesics is standard practice for many operations requiring
lower abdominal incision. This case report describes the use of TAP catheters to manage pain in a
difficult case of abdominal surgery. Patient consent was obtained prior to describing this case.
Material and methods: A 49-year-old male with a recent history of dilated non-ischaemic
cardiomyopathy, congested heart failure, NYHA functional classification 4, and an ejection fraction of
15% presented for rectosigmoid resection with end colostomy for sigmoid colon tumor. Additional
medical history included 2:1 atrial flutter, paroxysmal AF, COPD, morbid obesity (BMI 40.5),
suspected obstructive sleep apnoea, hypothyroidism, and smoking. Prior to surgery, the patient was
optimized medically with diuretics and ACE inhibitors, improving his functional status to NYHA 3A. No
further optimization was possible and he was keen to proceed to surgery despite the high risk of perioperative morbidity. Due to his complex cardiac history he was managed by a cardiac anesthetist
intraoperatively, and his cardiovascular system was supported by inotropes (dobutamine) and
vasopressors (norepinephrine) during surgery. Trans-esophageal echo was used for intra-operative
monitoring, and ICU admission was planned post-operatively. The acute pain service was consulted
for post-operative pain control, and a multimodal pain control regimen, including bilateral TAP
catheters and morphine PCA was advised. Surgery proceeded uneventfully.
Results: The TAP catheters were inserted postoperatively under ultrasound guidance superior to the
iliac crest in the mid-axillary line and bolused with 20 mL 0.2% ropivacaine. A continuous infusion of
1mL/hr 0.2% ropivacaine was then started with a 20 mL bolus regime every four hours to each side.
The patient was transferred to ICU post-operatively, and PCA morphine was commenced prior to
successful extubation the following morning. Pain control was managed satisfactorily, allowing
compliance with physiotherapy, deep breathing, and effective cough. Reported pain scores ranged
from 2-5 on the 0-10 scale, and the patient was ambulatory on post-operative day one. Morphine PCA
use was 26 mg for the first 24 hours and 30 mg for the second 24 hours. The TAP catheters were
discontinued on post-operative day three, and pain control remained satisfactory with PCA and then
oral analgesia until discharge. Discharge was delayed until post-operative day 23 due to postoperative ileus and then right portal vein thrombosis.
Discussion: For this complex case, we had to consider the planned ICU admission and time delay
until extubation. We therefore elected to place TAP catheters rather than single-shot blocks to ensure
optimal analgesia at the time of extubation. This technique proved successful at providing good
quality analgesia and can be considered in similar difficult cases.
References: 1. Petersen PL, et al. Acta. Anaesthesiol. Scand. 2010; 54: 529-535
Funding disclosure: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research
and the Canadian Anesthesiologists' Society.
Personal conflicts of interest disclosure: Nothing to disclose.
A195
ACUTE PAIN: LONG STANDING RHEUMATOID ARTHRITIS (RA) IN MIDDLE AGED FEMALE
S. Griffee, T. Oh
Mayo Clinic, Rochester, MN, USA
Introduction: Two middle-aged female patients, with over 20-year history of RA presenting with acute
onset of upper limb pain.
Material and methods:
Case #1: 52 year old female with 25 year history ofRA, requiring multiple surgeries including wrist
fusion, and shoulder arthoroplasty presented to outpatient clinic for exercise recommendations.
Patient's current exercise routine included 20 minutes daily walking, 15 minutes daily biking, and once
weekly 30 minutes of 4-pound kettle bells. Joint symptoms were well controlled on methotrexate,
abatacept and prednisone 5mg daily. She denied joint pain, except for pain in the left shoulder, most
notable during Kettlebell exercise. Exam demonstrated limited joint motion of bilateral wrists,
tenderness in the left shoulder and no significant synovitis. All other joints had full ROM. X-rays of the
right wrist revealed radiocarpal artrodesis with plate and screw fixation and fractures of the 2 fixation
screws in the scaphoid.
Case #2: 44-year-old female with 20-year history of RA. Patient with significant recent weight gain
and obesity, . Exercise routine included patient had recently joined a gym. Joint symptoms were well
controlled on methotrexate, Plaquenil, and Aleve. She admitted to hand and wrist pain noted after
workouts . Exam demonstrated limited motion of the wrist, swan neck and mild swan neck eformities
of the wrist, with subluxation of the MTP joints of the toes. X-ray revealed erosive changes in the
second MCP joints of the hands and MTP joints of the feet.
Discussion: In this case series, both patients presented with a long history of RA, but both were
unaware of exercise modification needed specifically for compromised joints.
In Case #1, patient with improper selection of exercise. Specifically kettle bell swings causing
significant stress on a compromised joint resulted in schaphoid fracture and shoulder pain.
In Case #2, patient with limited exercise, because of limited knowledge of proper exercise
modification resulted in sedentary lifestyle with weight gain adding significant stress to joints. On initial
assessment both patients were unaware of specific exercise limitation.
Results: After further review of exercise/past history, physical evaluation, and review of imaging, it
was determined that lack of exercise knowledge was a contributing factor to injury demonstrated on
imaging. Both were counseled on joint protection and referred to physical therapy for review of
exercise principles and proper technique for strengthening exercises.
Conclusion: This case series highlights that patients with long standing RA are often not aware of
proper exercise modification and joint protection principles. Specifically in women with RA, exercise
options are often not discussed until pain or injury presents. In conclusion, physician encounters
should include: review of the current exercise program (cardiovascular, strengthening, core stability
and previous exercise history), review medication, past medical/surgical history, imaging suspected
fractures, evaluation of gait and posture, inflammatory markers, and nutritional status. Counseling
about joint protection principals, alternative exercises such as Tai Chi, and referral to physical therapy
should be considered.
A196
PARSONAGE-TURNER SYNDROME FOLLOWING INTERSCALENE CATHETER PLACEMENT
R. Guha, M. Donnelly, K. Schroeder
University of Wisconsin, Madison, WI, USA
Introduction: Parsonage-Turner syndrome (PTS) is characterized by acute, severe neurogenic pain
in the shoulder or arm lasting for several days or weeks. This is followed by muscle weakness,
atrophy, and sensory loss as the pain diminishes. Both hereditary and acquired forms exist, with viral
infections, immunizations, strenuous exercise, and surgical procedures cited as causes. The
diagnosis is primarily clinical, supported by EMG and MRI. The condition usually completely resolves
over time and there is no definitive treatment otherwise. There is one case in the literature of PTS
following and interscalene block (ISB). We present a case of PTS following and interscalene catheter
(CISB) and a subsequent ISB during the course of the patient´s PTS.
Case description: A 51yo female with a history of low back arthritis underwent an arthroscopic right
shoulder rotator cuff repair, subacromial decompression, biceps tenotomy, and distal clavicle excision.
Prior to surgery, she experienced nine months of pain in her right shoulder with no specific
antecedent injury, as well as hand numbness. For surgery, a CISB was placed using ultrasound
guidance (USG) via the posterior approach. The catheter was test dosed, then dosed with
bupivacaine with 1:400,000 of epinephrine. Postoperatively, the patient had difficulty achieving
adequate pain control with the CISB, oral oxycodone, and ketorolac. Soon after the CISB was
removed, oxycontin was added. The patient continued to have considerable difficulty with pain control
but this gradually improved. Two months postoperatively, she had an atraumatic dislocation of her
shoulder, and suspicion was raised for PTS. The surgeon felt that paralysis of the supraspinatus,
infraspinatus, and deltoid muscles was developing from PTS.
Three months after her initial surgery, the patient underwent right shoulder open reduction, for which
she received an USG ISB again with bupivacaine and epinephrine. Her shoulder became dislocated
again in the recovery room, but was reduced in closed fashion. An EMG showed right suprascapular
neuropathy and coexisting right axillary neuropathy. This EMG in conjunction with her symptoms
supported a diagnosis of PTS.
The patient continued with physical therapy and opiates as needed for pain. Three months after her
second operation, her shoulder remains reduced and pain much improved, with significantly
decreased opiate use. A numb patch persists over her deltoid and deltoid strength remains limited,
but overall strength is improved.
Discussion: Interscalene blocks have been proposed as a possible mechanism for PTS, although
this is based on isolated case studies. Either surgery or interscalene catheter placement may have
contributed to PTS in this case; the patient denied other potential triggers. The clinical picture
suggests that it began after the initial surgery, classically presenting with pain initially and delayed
motor symptoms. Following shoulder surgery and ISB, severe pain that does not respond to usual
treatments should lead us to consider PTS as a diagnosis.
References:
Idiopathic Brachial Plexitis After Total Shoulder Replacement with Interscalene Brachial Plexus Block.
Tetzlaff et. al. Anesthesia and Analgesia 1997; 85: 644-6.
Neuralgic Amyotrophy (Parsonage-Turner Syndrome). Tjoumakaris et. al. Journal of the American
Academy of Orthopedic Surgeons 2012. 20 (7): 443-9.
A197
POST DURAL PUNCTURE HEADACHE AFTER THORACIC EPIDURAL TREATED WITH BLOOD
PATCH UNDER FLUOROSCOPY
P. Hagan, K. Hagan, K. Schroeder
1
2
Anesthesiology, University of Wisconsin Hostpital and Clinics, Madison, WI, USA
Introduction: Thoracic epidural blood patches (TEBP) are becoming increasingly important. This is
partially secondary to increased recognition of spontaneous dural tears as a cause of positional
headaches. TEBP is also occasionally required when iatrogenic injury (i.e. inadvertent “wet tap”) is the
cause of dural tear. A TEBP can be technically challenging for the anesthesiologist and little data
exists to guide any therapeutic intervention.
Case study: A 53 year old male patient presented for colovesicular fistula repair, sigmoid resection,
and loop ileostomy. A thoracic epidural was planned for postoperative analgesia. The resident first
attempted to access the epidural space via a midline approach at approximately T9-10, but
unsuccessful secondary to bony contact. The faculty anesthesiologist was subsequently able to enter
the epidural space via the paramedian approach. Of note, there was an acute needle “step-off” prior
to obtaining a loss of resistance but no fluid was noted to flow from the Tuohy. No fluid was returned
with aspiration of the epidural catheter and the test dose of 3mL 1.5% lidocaine with 1:200,000
epinephrine was negative. The planned surgical procedure was completed without complications and
an infusion of ropivacaine with hydromorphone was initiated in the recovery room.
On POD #2, the patient began complaining of a positional headache. Following failure of caffeine
supplementation and acetaminophen therapy, a TEBP through the in-situ epidural catheter was
planned. Despite a two day functioning epidural infusion and removal of the bacterial filter, the block
team was unable to inject any blood though the epidural catheter. A standard TEBP was then offered,
but the patient declined. On POD#3 the patient's surgical pain was controlled with oral narcotics and
he was tolerating a diet. The patient's headache persisted and he was counseled that a bedside
attempt at a TEBP was likely to be difficult, given the technical difficulty with his initial epidural
catheter insertion.
Because of this, interventional radiology was consulted for the TEBP procedure. At the request of the
interventional radiologists, a thoracic spine MRI was performed which demonstrated normal anatomy.
On POD#8, a fluoroscopically guided blood patch was performed at the T10-11 level with a 22 gauge
needle. Contrast was utilized to confirm positioning of the needle in the epidural space. 10mL of
autologous blood was then injected. The patient had great improvement in his headache and was
discharged home on POD#10.
Conclusions: Inadvertant thoracic dural perforation is relatively uncommon compared to the lumbar
level during epidural placement and headaches following thoracic dural puncture occur rarely. Most of
the teaching regarding EBP focuses on lumbar approaches. There are a number of questions that
need to be addressed regarding TEBP including, volume of blood required, safety of injection of large
volumes of blood adjacent to spinal cord, potential utility of performing lumbar EBP in the setting of a
thoracic dural puncture, how to evaluate a patient with back pain following TEBP and should
fluoroscopy be routinely considered when performing epidural blood patch in the thoracic region.
A198
BARTH SYNDROME: A REGIONAL ANESTHETIC APPROACH TO REDUCE PERI-OPERATIVE
CARDIAC MORBIDITY AND MORTALITY IN A PEDIATRIC PATIENT
1
2
1
D.M. Hall Burton , C.P. Honsinger , M. Visoiu , A. Davit
1
1
2
Anesthesiology, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, Anesthesiology,
3
University of West Virgninia, Morgantown, WV, Anesthesiology, Children's Hospital of Pittsburgh of
4
UPMC, Plastic Surgery, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
Introduction: Barth syndrome is a rare fatal x-linked disorder of lipid metabolism caused by a
mutation of the tafazzin gene that impairs cardiolipin formation and compromises mitochondrial
function.(1) Barth syndrome is characterized by progressive and fatal dilated cardiomyopathy,
proximal myopathy, neutropenia, growth retardation, organic aciduria, and feeding difficulty.(2)
Case report: A 17 month-old 8 kg male with Barth syndrome and associated dilated cardiomyopathy,
combined systolic and diastolic heart failure, neutropenia, and mild mitral insufficiency presented for
excision of right radial polydactyly and radial collateral ligament reconstruction.
In patients with significant cardiomyopathy, anesthetic related vasodilatation, bradycardia, and
myocardial depression can cause catastrophic hemodynamic instability. Pain can cause increased
peripheral resistance, heart rate, stroke volume, myocardial work, and oxygen demand. Increased
heart rate further limits coronary oxygen delivery. We determined that a balanced anesthetic of
inhalation agent, opiate, and a brachial plexus nerve block would provide optimal peri-operative
hemodynamic stability.
After premedication with midazolam an inhalational induction was performed. A peripheral IV and
LMA were placed. Anesthesia was maintained with a 0.5 MAC mixture of sevoflorane, nitrous oxide
and oxygen. A supraclavicular nerve block was then performed. The block was performed in the
classic supraclavicular position with the probe positioned in the transverse oblique orientation in the
supraclavicular fossa. The subclavian artery, first rib, pleura, anterior and middle scalene, and
brachial plexus were easily identifiable. A 22G 40mm Pajunk sonographic stimulating needle was
inserted under ultrasound guidance and directed underneath the brachial plexus to the angle formed
by the posterolateral aspect of the subclavian artery and the first rib. After negative aspiration, 8 mg
ropivacaine was injected. Local anesthetic was seen surrounding the nerves. The surgical case was
then completed without complication. The LMA was removed at the conclusion of the case and the
patient was taken to the recovery room.
Postoperatively the patient received acetaminophen and one dose of oxycodone prophylactically. He
was pain free and motor function returned by post-operative day one. He was discharged on postoperative day two.
Discussion: Patients with Barth syndrome present many challenges for the anesthesiologist.
Anesthetic agents, opiates and post-operative pain can have significant morbidity or mortality.
Ultrasound guided supraclavicular nerve blocks can be performed quickly with a low
anesthetic. It allowed the patient to tolerate the surgical procedure and tourniquet
minimal volatile anesthetic agent and opiate use. Using a low concentration of local
limited its potential for myocardial depression. Post-operative pain was well
hemodynamic instability occurred.
volume of local
placement with
anesthetic also
controlled. No
The regional anesthetic minimized the patient's anesthetic and surgical risk. His procedure was
completed with minimal anesthetic exposure, adequate pain control, and he was discharged to home
on post op day two without complication.
[Pre-Operative Radial Polydactyly]
[Post-Operative Radial Polydactyly]
1. Gonzalez IL. Barth syndrome: TAZ gene mutations, mRNAs, and evolution. Am J Med Genet A
2005;134:409-414.
2. Barth PG, Wanders RJ, Vreken P. X-linked cardioskeletal myopathy and neutropenia. J Pediatr
1999;135:273-276.
Nothing to disclose
A199
RECTUS SHEATH NERVE BLOCK CATHETERS FOR MIDLINE ABDOMINAL INCISIONS IN
PEDIATRIC PATIENTS: A REGIONAL ANESTHETIC APPROACH TO POSTOPERATIVE PAIN
MANAGEMENT
D.M. Hall Burton, J. Smolinski, M. Visoiu, I. Galay, A. Cassara
Anesthesiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
Introduction: Epidural analgesia is the gold standard for abdominal surgical incisions, however co1
morbidities and side-effects limit its use. Peripheral nerve blocks are performed to provide analgesia
in patients who are not candidates for neuraxial techniques or to minimize complications. Rectus
2
sheath catheters have been described for adult patients, but not for use with children. We
encountered two pediatric patients with midline surgical incisions requiring post-operative analgesia.
For each, we performed bilateral rectus sheath nerve blocks with catheters (RSNBC) for postoperative analgesia.
Case 1: An 18 year-old 54 Kg female with Crohn's disease presented for laparoscopic ileocecectomy.
The surgical approach involved a 5cm midline incision. Following surgery under general anesthesia,
ultrasound guided bilateral RSNBCs were placed between the rectus muscle and sheath along the
lateral edge of the muscle at umbilical level. Catheters were bloused with 10mL of 0.5% ropivacaine.
In the post-anesthesia care unit (PACU), nerve block infusions of 0.2% ropivacaine at 5ml/hr per side
with 1ml/hr clinician bolus were started. Visual analog scale (VAS) pain scores and opiate use are
listed in Figure 1. Post-operatively she received acetaminophen every 6 hours for 4 days. POD 2 pain
was intermittent sharp “gas” type pain. Nerve block infusions were suspended on POD 3, and her
pain increased to VAS 7-10/10. Catheters were bolused and infusions restarted. On POD 4, catheters
were suspended and her VAS increased from 2-5/10. Catheters were then removed. She identified a
numb area along the midline from T7-T12 for the blocks' duration.
[Figure 1]
Case 2: A 13 year-old 69 Kg male presented for exploratory laparotomy and removal of ingested
foreign body. The surgical approach involved a 4cm midline incision. Following surgery under general
anesthesia, ultrasound guided bilateral RSNBCs were placed between the rectus muscle and sheath
along the lateral edge of the muscle at umbilical level. As the catheters were bloused with 5mL of
0.5% ropivacaine, an ellipsoid shape was noted as the rectus muscle pushed away from the sheath.
Nerve block infusions of 0.2% ropivacaine at 8mL/hr with a 2mL/hr clinician bolus were started in the
PACU. Acetaminophen was given every six hours for three days. FLACC scores and opiate use are
listed in Figure 2. RSNBCs were suspended on POD 3 and removed without complication.
[Figure 2]
Discussion: As an alternative to continuous epidural analgesia for midline abdominal incisions in
pediatric patients, we attempted rectus sheath nerve block catheters. Both times, catheters easily and
effectively provided sensory analgesia from T7-T12. No side effects or complications from the nerve
blocks were noted. Opiate use was minimal and the patients were satisfied. Additional studies are
needed to further assess continuous rectus sheath nerve blocks in pediatric patients.
References:
1. Brown DL. Spinal, epidural, and caudal anesthesia. Miller's Anesthesia. 7th ed. Philadelphia:
Churchill Livingstone, Elsevier Inc; 2009. P. 1611-8.
2. Sandeman DJ, Dilley AV. Ultrasound-guided rectus sheath block and
catheter placement. ANZ Journal of Surgery 2008; 78: 621-3.
Personal conflicts of interest disclosure: Nothing to disclose.
A200
INTRAVASCULAR FEMORAL NERVE CATHETER RESULTS IN CNS TOXICITY WITH LOWDOSE ROPIVACAINE
A. Puri, M.W. Harbell, P. Aleshi
Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, USA
Introduction: Local anesthetic systemic toxicity (LAST) is a rare but well documented complication of
regional anesthesia. The minimum dose of ropivacaine thought to produce toxicity is 3mg/kg. We
report a case of an intravascular femoral nerve catheter (FNC) resulting in CNS toxicity with low-dose
ropivacaine.
Case report: A 43-year-old, 96-kg, ASA physical status II male scheduled for revision total knee
arthroplasty underwent an ultrasound-guided femoral nerve block with 20mL of ropivacaine 0.5%,
after which a FNC was placed for postoperative analgesia. He had an uneventful operative course
under subarachnoid block and propofol infusion for sedation. Upon arrival to the PACU, he was
hemodynamically stable, awake, and comfortable. The FNC infusion was started with ropivacaine
0.1% infusing at 8mL/hr. After 30 minutes, the patient became hypotensive and somnolent, but
arousable. He complained of lightheadedness, perioral numbness, a metallic taste in his mouth and
exhibited muscle twitching of his upper trunk and extremities. He received midazolam followed by a
bolus of Intralipid and his blood pressure was supported briefly with fluid boluses and phenylephrine.
Following the resolution of his symptoms, a test dose containing epinephrine was administered via the
FNC (after a negative aspiration) resulting in a clear rise in heart rate, confirming the intravascular
location of the catheter.
Discussion: LAST remains a significant clinical concern when performing regional anesthesia. The
incidence of LAST ranges from 7.5 to 20 per 10,000 peripheral nerve blocks, however the incidence
1
may be underreported.
Systemic toxicity results from elevated plasma local anesthetic levels above a threshold level, most
often due to inadvertent intravascular injection, and less frequently from systemic absorption of local
2,3
anesthetic from a tissue depot.
This case is interesting because of the very low dose of ropivacaine that the patient received, a total
of less than 1.1mg/kg including both the initial bolus preoperatively (100mg) and the infusion in the
PACU afterwards (4mg). Assuming all of the ropivacaine was injected intravascularly, it is surprising
that this dose resulted in CNS toxicity. It is also unclear whether the toxicity developed in response to
the initial bolus, in which case the presentation was delayed or potentially masked by the propofol he
received intraoperatively, or whether it resulted from initiation of the infusion in the PACU. Other
factors such as the rate of injection, drug-drug interactions, or patient factors may ultimately help
explain why this patient was susceptible to LAST.
References:
1
Mulroy MF. Systemic toxicity and cardiotoxicity from local anesthetics: incidence and preventive
measures. Reg Anesth Pain Med 2002;27(6):556-561.
2
Di Gregorio G, Neal JM, Rosenquist RW, et al. Clinical presentation of local anesthetic systemic
toxicity: a review of published cases, 1979 to 2009. Reg Anesth Pain Med 2010;35(2):181-7.
3
Neal JM, Bernards CM, Butterworth JF, et al. ASRA practice advisory on local anesthetic systemic
toxicity. Reg Anesth Pain Med 2010;35(2):152-61.
Funding: None
Personal conflicts of interest disclosure: Nothing to disclose.
A201
MULTIDISCIPLINARY APPROACH TO A PATIENT WITH AN ATYPICAL ACUTE HEADACHE
R. Harris, K. Schroeder
Anesthesiology, University of Wisconsin, Madison, WI, USA
A 38-year-old woman with history of seasonal migraine headaches presented to the ED seventy-two
hours after the acute onset of a severe positional headache. Initial therapy consisted of IV fluid
administration and opioid administration. Neurosurgery consultation and head/spine MRI's failed to
reveal an etiology for the patient's persistent headaches. Fifteen days of persistent positional
headaches prompted neurosurgery to request a therapeutic lumbar epidural blood patch (EBP) for
treatment of presumed spontaneous intracranial hypotension (SIH). Following L3-4 EBP with 20 ml of
autologous blood, the patient reported immediate relief of her positional headache. Positional
headache symptoms returned three days later and a neurology consult then recommended a repeat
EBP, this time performed by interventional pain specialists at T4-T5 under fluoroscopic guidance.
After only transient improvement in positional headache symptoms, a third EBP was performed at C7T1 under fluoroscopic guidance. Failure of this third EBP to resolve positional headache symptoms
prompted a CT myelogram. Results of the CT myelogram revealed a T6-7 dural tear. The patient
underwent surgical repair of her dural tear the following day, and her headaches resolved rapidly.
Discussion: SIH is a syndrome that can lead to persistent daily headaches. These headaches are
most often orthostatic in nature, mimicking post-dural puncture headaches (PDPH). As acute and
chronic pain practitioners, anesthesiologists will potentially be called upon to aid in the treatment of
these patients. It is therefore important to understand the pathophysiology, diagnosis, and treatment
of this condition.
SIH may often occur when there is cerebrospinal fluid (CSF) leakage into the subdural or epidural
space. The meninges, cerebral and cerebellar veins, as well as cranial nerves V, IX, and X are all
pain-sensitive structures that may lead to discomfort if the normally buoyant brain becomes less
buoyant secondary to decreased CSF levels. History alone should be enough to raise a very high
level of suspicion, as these patients will often have a clear orthostatic component to their headaches.
Cranial MRI will often show subdural/extrathecal CSF, enhancement of the meninges, engorgement
of the venous structures, pituitary hyperemia, or sagging of the brain.
These patients may present to their primary care physician, the ED, or a pain clinic, and
anesthesiologists may be called upon to treat them. Conservative treatment generally includes bed
rest, oral hydration, caffeine, and acetaminophen. EBP's have a reported efficacy of 80-90% on the
first attempt in PDPH patients, and these may be more effective if done at the sight of the dural tear.
Finally, definitive treatment for refractory headaches, as in our patient, is surgical repair of the
structural defect.
A coordinated multidisciplinary approach is required to optimize patient outcomes. This patient
prompted a formal discussion between neurology, anesthesia acute pain service and interventional
pain physicians to develop a protocol outlining the appropriate sequence/location of EBPs and who
should be responsible for their placement. Plan concordance between care team members will allow
for clear expectations when management consultation for patients with SIH occurs.
Funding / Personal conflicts of interest disclosure: There are no conflicts of interest or external
funding to report.
A202
PERSISTENT PHRENIC NERVE PARESIS AFTER SHOULDER SURGERY UNDER
SUPRACLAVICULAR BLOCK: REPORT OF TWO CASES
S. Haskins, T. Quinn, A.C. Lee, V. Zayas
Anesthesiology, Hospital for Special Surgery, New York, NY, USA
Transient Phrenic Nerve Paresis (TPNP) occurs with an incidence of 13 - 100% after interscalene
block (ISB).(1)(2) Persistent phrenic nerve paresis (PPNP) has been reported after interscalene block
(ISB) for shoulder surgery(3) but not after supraclavicular block (SCB). We present 2 cases of PPNP
following US-guided SCB and shoulder surgery in the sitting position.
Case 1: A 62 yo female underwent right total shoulder replacement (TSR) following a left TSR 14
weeks earlier under US-guided SCB. Her history was notable for morbid obesity (BMI 44.9). Preoperative chest x-ray (CXR) was read as poor inspiratory effort and possible left basilar atelectasis
(Fig 1).
Following an US guided in-plane SCB with 55mL bupivacaine 0.25% plus dexamethasone PF 4 mg
using a Chiba needle, general endotracheal anesthesia was induced and the patient placed in the
sitting position.
Upon extubation, the patient complained of dyspnea and was hypoxic requiring assisted mask
ventilation. (ABG: pH 7.20, PCO2 68 and PO2 117). Intraoperative fluoroscopic examination revealed
bilateral diminished diaphragm function on deep inspiration. Comparison of the 2 preoperative CXRs
(Fig 1) and (Fig 2) revealed a new contralateral (left) hemidiaphragmatic elevation.
Postoperatively the patient required BiPAP for >24 hours. In retrospect, the patient had dyspnea and
shortness of breath following her prior surgical procedure.
[Figure 1 - Preoperative CXR]
[Figure 2 - CXR from Previous Admission]
Case 2: A 59 yo male underwent arthroscopic right shoulder surgery in the sitting position. An US
guided SCB was performed with an in-plane Chiba needle using 50mL of mepivacaine 1.5% and
10mL of bupivacaine 0.5% plus epinephrine 1:500,000. The patient was discharged home the same
day.
Several days later, he noted dyspnea while lying down to sleep and with normal activities. CXR
revealed an elevated right hemidiaphragm. Following pulmonary function tests, a diagnosis of phrenic
nerve paresis was made. MRI revealed multilevel C-Spine pathology.
Discussion: We reported the incidence of PPNP following ISB for shoulder surgery in the sitting
position as 1/2069.(3) It is possible that direct needle trauma to the phrenic nerve may occur with ISB
and, potentially with rare anatomical variants, also SCB (4). However, anatomically, it is unlikely that
the phrenic nerve would be directly injured during SCB.
We propose that positioning and stretch cause PPNP. PPNP has been reported following minor
cervical trauma (5), stretch injuries (6), chiropractic manipulation of the neck (7) and with C-Spine
disease.(8) Brachial plexus monitoring during TSR under general anesthesia demonstrated nerve
dysfunction in 57% of patients. (9) Anatomically, these cases of PPNP were likely secondary to the
stretch and position and not SCB.
References:
1. Urmey et al. Anesth Analg 1991;72:498-503
2. Renes et al. Reg Anesth Pain Med. 2009;34(6):595-9
3. Zayas, ASRA 2009
4. Gupta et al. J Pain, Symptom Control and Palliative Care. 2009;7(1)
5. Bell et al. J Accid Emerg Med. 2000;17(6):419-20
6. Synder et al. JTrauma. 1994;36(5):734-6
7. Merino-Ramirez et al. Muscle Nerve 2007; 36(2): 267-70
8. Li, ASRA 2011
9. Nagda et al. J Should Elb Surg 2007;16:2S-8S
A203
FEMORAL NERVE CATHETER PLACEMENT FOR ACL REPAIR COMPLICATED BY A FULL
THICKNESS SKIN WOUND
H.J. Heyman, D.M. Hunter
1
2
Anesthesiology, Orthopaedic Surgery, Georgia Health Sciences University, Augusta, GA, USA
Objective: To describe an unusual complication after femoral nerve catheter placement.
A 15 yo female presented for ACL reconstruction after a ground level fall. Past medical history
consisted of morbid obesity with a BMI of 46, no known allergies, previous surgeries or anesthesia.
An anesthetic plan was discussed and was decided to proceed with general anesthesia combined
with femoral nerve catheter for postoperative analgesia. Catheter placement was performed
preoperatively under ultrasound guidance with an Arrow stimulating catheter. Placement was
uneventful with quadriceps twitch obtained to a minimal current of 0.8mA, negative test dose and was
bolused with 20ml of ropivacaine 0.5%. The catheter was tunneled laterally using a touhy needle and
stylette and secured with mastisol and tegaderms. The tunnel site was anesthetized with a mixture of
the remaining 2ml 1.5% lidocaine with 1:200,000 epinephrine from the test dose vial and another 4 ml
of 1% lidocaine plain. The patient proceeded to the operating room where she underwent general
anesthesia and the procedure was completed without incident. Intraoperatively the femoral catheter
infusion was started with ropivacaine 0.2% at 10ml/hr. Postoperatively she complained of no pain in
the post-anesthesia care unit and was transferred to the pediatric floor with the femoral nerve catheter
infusion. While on the floor she continued to have no pain and remained hospitalized one night. She
was to be discharged the morning after surgery and was offered an ambulatory femoral nerve
infusion. She declined ambulatory infusion and the catheter was removed without difficulty. The
patient reported return of normal sensation and motor strength within several hours of the infusion
being stopped.
She was next seen by her surgeon 6 days later and was found to be progressing normally and had no
new complaints. She was seen the following day by physical therapy who noted a 5cm x 4cm full
thickness skin wound at her upper thigh in the area of the nerve block. The wound had no erythema
or drainage and appeared clean. Patient stated she had noticed it just that day as it is located under a
large abdominal pannus and was not visible to her and caused no pain. She was referred to plastic
surgery for evaluation. The plastic surgeon recommended silvadene daily and to follow up in one
week. At the one week follow up the wound appeared clean and had not progressed. She was offered
excision and primary closure to accelerate healing but declined. She was recommended to continue
silvadene and to return in one week, however was lost to follow up after this appointment. She
continued to be seen by physical therapy and voiced no further complaints about the wound.
Potential causes for the wound include unrecognized reaction to the tegaderms, mastisol or
epinephrine containing lidocaine at the tunnel site, and less likely infection. Progression of the wound
was likely due to the patient´s abdominal pannus covering the site impeding healing and earlier
recognition by the patient herself.
[Skin Wound]
Personal conflicts of interest disclosure: Nothing to disclose.
A204
ULTRASOUND GUIDED AIRWAY BLOCKADE FOR AWAKE FIBEROPTIC INTUBATION
D. Demaculangan, J. Hedden, L. Maracaja-Neto, A. Hummel, J. Mazer
Department of Anesthesiology, SUNY Health Science Center at Brooklyn, Brooklyn, NY, USA
Airway preparation using nerve blockade for awake intubation is often performed using surface
landmarks and palpation of underlying target structures. However, these blocks can be challenging to
do in those with thick short necks or abnormal neck anatomy. Ultrasound (US) guidance is widely
used in nerve block procedures, but it has rarely been used for airway blockade (Manikandan1,
DeOliveira2, Green3).1,2,3 The sonoanatomy of the airway has been extensively described (Singh4,
Kundra 2011,5, Kristensen6)4,5,6. These sonoanatomical descriptions can be used to facilitate the
performance of airway blocks such as the superior laryngeal nerve (SLN) and translaryngeal/recurrent
laryngeal nerve (TL/RLN) blocks. We present systematic technical descriptions of US guided SLN and
TL/RLN blocks performed on two patients who underwent awake fiberoptic intubation (FOI). We
review the techniques described in previous reports and present new alternative approaches. We also
describe imaging artifacts from the air-membrane interface (AMI) present in the airways that can
mislead the anesthetist if not recognized.
A205
A SUCCESSFUL USE OF THE ALTERNATIVE CATHETER-OVER-NEEDLE ASSEMBLY FOR
CONTINUOUS LOWER INTERSCALENE BLOCK IN DISTAL HUMERUS SURGERY AND
OLECRANON SURGERY: A CASE REPORT
V.H.Y. Ip, B.C.H. Tsui
Department of Anesthesia and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: The interscalene blocks spares the lower trunk of the brachial plexus in approximately
1
2
half of all cases. Low interscalene single-shot blocks have been successful for elbow surgery, but
there is currently no literature regarding the successful use of low interscalene catheters. Here, we
demonstrate the successful use of low interscalene catheter for distal humerus and olecranon surgery
using a non-traditional method to place the catheter. Consents have been obtained.
Material and method: A 77-year-old female, was scheduled for open reduction and internal fixation
of a comminuted fracture of the left humerus. A low interscalene catheter was inserted pre-operatively
under ultrasound guidance with a 13-6 MHz high frequency linear transducer. After a local anesthetic
3
wheal was raised, a 21G x 95 mm catheter-over-needle unit was directed in-plane towards the
interscalene groove, between the C5 root and the trunks of the brachial plexus. After confirming the
spread of dextrose 5% in water (D5W), 25 mL of local anesthetic was injected between the sheath
and the roots. The needle was withdrawn, and a flexible, 20G x 75 mm inner catheter was inserted
through the 18G outer catheter and was Luer-locked in place. Under ultrasound, the spread of 5 mL
of local anesthetic was observed as it was injected through the catheter (Figure-Arrows pointing at the
catheter and the asterix shows the spread).
[Lower interscalene catheter]
Surgery proceeded uneventfully.
Results: No leakage was noted at the site of the catheter insertion after either bolus, and a good
sensory block was achieved. Local anesthetic infusion continued for two days, and the patient
remained comfortable throughout this recovery period. The catheter was removed, and no evidence
of kinking was observed. The dressing remained dry and intact at 72 hours postoperatively.
Subsequently, we performed a similar procedure with similar successful results on a patient who
underwent open reduction and internal fixation of the right olecranon.
Discussion: Our preliminary results from these two cases demonstrate the successful use of the
alternative catheter-over-needle assembly to provide continuous low interscalene nerve block for
distal humerus surgery. The catheter-over-needle assembly provides a stable, effective means of
delivering a continuous interscalene block that mitigates the problems of the traditional approach.
References:
1. Neal JM et al. Reg Anesth Pain Med. 2009; 34: 134-70.
2. Gadsden JC et al. J.Clin.Anesth 2009; 21: 98-102
3. Ip V et al. Can. J. Anesth. 2012; 59: 1125-9
Funding: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research and the
Canadian Anesthesiologists' Society.
Personal conflicts of interest: The Pajunk MultiSet 211156-40E is modified and re-designed by Ban
Tsui. Dr. Tsui also has a patent-licensing agreement with Pajunk.
A206
INTERCOSTAL CATHETER PLACEMENT FOR CHEST TUBE RELATED PAIN IN PATIENTS
UNDERGOING PULMONARY RESECTION WITH CONTRAINDICATIONS TO EPIDURAL BLOCK
J. Jackson, V. Puttanniah, A. Gulati
1
2
NewYork-Presbyterian Hospital, Weill Medical College of Cornell University, Memorial Sloan
Kettering Cancer Center, New York, NY, USA
Introduction: Thoracic surgery involving the placement of a chest tube is painful, and adequate
analgesia is necessary in order to maximize postoperative pulmonary function and reduce the risk of
complications. While thoracic epidural analgesia is typically employed for postoperative pain
management in these cases, it is not without risks and side effects. Further, some patients are
ineligible for placement. We describe two cases of effective analgesia via continuous intercostal
blockade in patients who were unable to undergo epidural placement.
Material and methods: Two patients undergoing pulmonary resection with contraindications to
epidural placement, which included anticoagulation with Plavix in the first case and the presence of an
intrathecal pain pump in the second case, underwent ultrasound-guided intercostal nerve blockade
and catheter insertion at the level of chest tube placement at the end of surgery. Patients were initially
given an 8-10 mL bolus of ropivacaine 0.2% during placement, and subsequently ropivacaine 0.10.2% was infused at 5mL/hr until the chest tube was removed. Supplemental analgesia was provided
with intravenous patient controlled analgesia (IVPCA) and ketorolac. The patients were then
evaluated for postoperative pain control, side effects, and any complications daily by the pain service
until the catheter was discontinued.
Results: Intercostal blockade was highly effective in both patients in terms of postoperative pain
control and preservation of pulmonary function. Both patients rated their pain as acceptable
throughout the entire duration of follow-up, with pain scores ranging from 2-6 on a 10-point scale in
the first patient and from 4-5 in the second patient. IVPCA usage ranged from 1.2-3.4 mg of morphine
equivalents per hour. No complications from catheter placement were observed. Side effects were
minimal and primarily consisted of nausea in one patient attributed to intravenous opioids.
Discussion: These cases suggest that intercostal nerve blockade via a continuous infusion of local
anesthetic is a safe and effective alternative for management of chest tube related pain in patients
undergoing pulmonary resection with a contraindication to epidural placement.
References:
Concha M, Dagnino J, Cariaga M, Aguilera J, Aparicio R, Guerrero M. Analgesia after thoracotomy:
epidural fentanyl/bupivacaine compared with intercostal nerve block plus intravenous morphine. J
Cardiothorac Vasc Anesth 2004;18(3):322-6.
Detterbeck F. Efficacy of methods of intercostal nerve blockade for pain relief after thoracotomy. Ann
Thorac Surg 2005;80:1550-9.
Joshi GP, Bonnet F, Shah R, Wilkinson RC, Camu F, Fischer B, Neugebauer EAM, Rawal N, Schug
S, Simanski C, Kehlet H. A systematic review of randomized trials evaluating regional techniques for
postthoracotomy analgesia. Anesth Analg 2008;107:1026-40.Kaiser A, Zollinger A, De Lorenzi D,
Largiader F, Weder W. Prospective, randomized comparison of extrapleural versus epidural analgesia
for postthoracotomy pain. Ann Thorac Surg 1998;66:367-72.
Katayama T, Hirai S, Kobayashi R, Hamaishi M, Okada T, Mitsui N. Safety of paravertebral block in
patients ineligible for epidural block undergoing pulmonary resection. Gen Thorac Cardiovasc Surg
2012;60:811-14.
Takamori S, Yoshida S, Hayashi A, Matsuo T, Masahiro M, Shirouzu K. Intraoperative intercostal
nerve blockade for postthoracotomy pain. Ann Thorac Surg 2002;74:338-41.
Funding: Nothing to disclose
Personal conflicts of interest disclosure: Nothing to disclose
A207
SUCCESSFUL ADDUCTOR CANAL CATHETER AND POSTERIOR TIBIAL NERVE BLOCK FOR
A PATIENT WITH ACHONDROPLASTIC DWARFISM FOR TOTAL KNEE REPLACEMENT
M. Jacobson, M. Tu, B. Kosharskyy, N. Shaparin, K. Gritsenko
Anesthesiology, Montefiore Medical Center - Albert Einstein College of Medicine, Bronx, NY, USA
Introduction: The most commonly dwarfism, achondroplastic, occurs in 1:15-40,000 births annually
(1). Associated findings include airway abnormalities, sleep apnea, thoracic kyphosis, and scoliosis,
(1) yet Pubmed analysis shows no data regarding regional anesthesia techniques for lower extremity
orthopedic procedures.
Case: A 4´3 130lb woman presented for knee replacement. Leg length measured 64 cm from anterior
superior iliac spine to lateral malleolus. An adductor canal catheter and tibial nerve block was
planned.
Under ultrasound guidance, an 18 gauge 2 inch Tuohy needle was advanced in-plane toward the
adductor canal; 20mL of 0.5% Ropivacaine and 4 mg dexamethasone was injected. Catheter was
positioned through the tuohy and secured. The knee was repositioned in 30 degree flexion and tibial
nerve was identified at the popliteal groove. A 90mm, 21 gauge needle was advanced medially inplane with peripheral nerve stimulation; 10mL of 0.5% Ropivacaine and 4mg of dexamethasone was
injected.
Anesthetic was discussed preoperatively; as catheter in mid-thigh allowed only 11 cm between
insertion site and lateral aspect of the knee, limiting surgical field. The surgeon placed the tourniquet
immediately on the adductor canal catheter while monitoring for kinking or dislodgement. Surgery was
performed under general anesthesia. Peripheral catheter infusion was initiated postoperatively using
0.2% Ropivacaine continuously at 6ml/hr for 2 days. The patient reported excellent analgesia in the
first 24 postoperative hours; 5mg in PACU and 4mg via IV PCA. On POD#2, she required 52mg of IV
Morphine via PCA, which may have been related to catheter movement or posterior knee pain from
resolved tibial blockade. Patient was discharged on POD#3. The orthopaedic surgeon confirmed
excellent patient satisfaction at 1 week follow-up.
[Posterior Tibial Block]
[Adductor Canal Block]
Conclusion: Documented quadriceps weakness and falls in patients receiving femoral nerve
blocks/catheters for total knee replacements led to newly popular and successful adductor canal
blocks/catheters targeting the saphenous nerve to be used in the adult population (2). Catheters
placed into the adductor canal can infuse local anesthetic, reducing pain scores, increasing time to
requiring breakthrough pain medication, allowing earlier ambulation, and reliably provide knee pain
relief postoperatively (3,4). In combination, adductor canal and tibial blocks can allow for superior
analgesia (3,4). This case report indicates excellent postoperative pain control in a patient with altered
anatomy.
References:
1. Monedero, P., et al., Is Management of Anesthesia in Achondroplastic Dwarfs Really a Challenge?
Journal of Clinical Anesthesia. 9:208-212, 1997.
2. Jenstrup, M.T., Jaeger, P., Lund, J., Fomsgaard, J.S., Bache, S., Mathiesen, O., Larsen, T.K., and
Dahl, J.B., Effects of Adductor-Canal-Blockade on pain and ambulation after total knee arthroplasty: a
randomized study. Acta Anesthesioogica Scandanavica. 56: 357-364. 2012.
3. Anderson, H., Gyrn, J., Moller, L., Christensen, B., and Zaric, D., Continuous Saphenous Nerve
Block as Supplement to Single-Dose Local Infiltration Analgesia for Postoperative Pain Management
after Total Knee Arthroplasty. Regional Anesthesia and Pain Medicine. October, 2012.
4. Kapoor, R., Adhikary, S.D., Siefring, C., and McQuillan, P.M., The saphenous nerve and its
relationship to the nerve to the vastus medialis in and around the adductor canal: an anatomical
study. Acta Anesthesiologica Scandanavia. 56: 365-367. 2012.
A208
MANAGEMENT OF UNREMITTING SICKLE CELL PAIN IN A DIFFICULT PATIENT
A. Kalava, S. Jafari, J.M. Yarmush, J. SchianodiCola
New York Methodist Hospital, Brooklyn, NY, USA
Introduction: Pain during sickle cell crisis is an emergency. Hydration, anti-inflammatory drugs,
aggressive analgesia, and possibly vasodilators could abort the crisis and prevent or minimize further
damage. Relative opiate tolerance, allergies to opiates and patient refusal to traditional therapy
makes pain control in these patients extremely difficult. We present a case of a 21 yr old who had
minimal pain relief with intravenous ketamine and underwent exchange transfusion as a last resort
with good result.
Case report: 21 year old male, with sickle cell disease, prior history of acute chest syndrome,
recurrent priapism, hypertension, s/p bilateral hip replacement, presented with generalized pain in the
muscles, back, thigh and chest. He also reported priapism which lasted 5 hours the night before
presentation. He was oxycodone dependent with daily dose requirements of up to 30mg every
4hours. He ran out of oxycodone, after which the symptoms began. He also reported major allergy to
hydromorphone. Laboratory data ruled out sepsis, acute chest syndrome and aplastic crisis. His penis
was flaccid.
On admission, he was started on oxygen, IV hydration, NSAID's and IV morphine and
methocarbamol, hydroxyurea and folic acid. On day 2 of admission, pain management was consulted
as he had recurrence of priapism and as he complained of intolerable pain. Urologists administered
intracavernous dose of 1 ml of 1% phenylephrine with good detumicense and the patient was started
on morphine patient controlled analgesia (PCA) at a basal rate of 0 mg, patient bolus 2 mg every 8
minutes after a load dose of 5 mg, along with oxycodone (controlled release) 30mg every 4 hours.
Over the next few days patient needed escalating doses of morphine PCA reaching a basal rate of
2mg, bolus of 4.5mg every 8 minutes by day 5.
On day 6, patient had a recurrence of priapism with spontaneous resolution and reported generalized
intolerable pain with the analgesic regimen he was on. Treatment options of epidural analgesia, nerve
blocks, change of opioids both the IV form and the oral form, adding the adjuvant meds, were all
refused by the patient. After a long debate, patient consented to try IV ketamine in addition to
morphine PCA, which was started at 7mg/hour and titrated up to 12 mg/hour in less than 24 hours.
Following ketamine infusion patient continued to complain of moderately severe pain at which point
exchange transfusion was considered. Exchange transfusion was performed on day 8 with good pain
relief. Ketamine infusion was slowly tapered and stopped on day 11. Patient was transitioned to
methadone 20mg once daily, gabapentin 300mg Q8hourly and low dose morphine PCA at this time.
He is slated for a discharge soon.
Discussion: Traditionally exchange transfusion in sickle cell is reserved for acute stroke, acute chest
syndrome with severe hypoxia, acute multi-organ failure, and possibly acute severe priapism. In
patients who fail to respond to traditional analgesic treatment with opiates and low dose infusions of
ketamine, exchange transfusion can be tried as a last resort.
A209
REDUCTION OF HIP DISLOCATION WITH FASCIA ILIACA COMPARTMENT BLOCK
U. Kaldirim, S.K. Tuncer, S. Bilgic, M. Yetim
1
2
Emergency Medicine, Anesthesiology, Gulhane Military Medical Academy, Ankara, Turkey
Introduction: In aging societies hip fracture incidence increases. Trochanteric fractures account
about half of all hip fractures in geriatric people. Reduction and pain control in patients with hip
dislocation is quite difficult. Pain management with drugs may cause a large variety of deleterious side
effects especially in aged. Method of choice includes Fascia iliaca compartment block in femur
fractures (1). In this report, we describe a 65-year- old woman who presented with right hip pain and
limping as a result of trauma had fascia iliaca compartment block (FICB).
Case: 65-year-old female with right hip pain and limping as a result of a low energy trauma was
admitted to emergency department. Her past medical history revealed arterial hypertension, chronic
obstructive lung disease and surgery of total right hip with internal fixation. Sensorial, motor and
peripheral arterial examination of right limb was otherwise non-contributory. Radiologic assay
revealed dislocation of right limp with internal fixation. Reduction was unsuccessful in first attempt. For
pain control and ease of reduction, ultrasound guided FICB was decided to perform when effects and
her comorbidity were taken into consideration. Her vital signs were in normal range except oxygen
saturation of 88 % on room air.at a time (Figure). Totally 30cc of medicine including 5cc of normal
Saline, 15cc of 0.5% Bupivacaine and 10cc of 1% Lidocaine were administered on site of fascia iliaca
compartment. After providing adequate anesthesia; reduction was successfully performed at a time
with Allis´s maneuver. Patient was hospitalized in orthopedic service for further examination.
Discussion: Although hip dislocation is not so common in patients with internal fixation; it is one of
the reasons of admittance to Emergency Department. In the treatment of patients with no other
clinical findings suggestive of fracture or corruption in internal fixator, reduction is adequate.
Reduction is a painful and difficult procedure. Analgesia even sometimes procedural sedation is
advised to promote successful manual reduction. Method of choice includes Fascia iliaca
compartment block in femur fractures (1, 2). Peripheral nerve blockade is advised to be performed
with sonographic guidance in order to perform in ease and safety (3). In our case we preferred
ultrasound guided FICB. reduction was incredibly easy and free of pain. Hip dislocation with or without
fractures managed with FICB will ease the management of dislocation.
References:
1. Elkhodair S, Mortazavi J, Chester A, Pereira M. Single fascia iliaca compartment block for pain
relief in patients with fractured neck of femur in the emergency department: a pilot study. Eur J Emerg
Med. 2011 Dec;18(6):340-3.( PMID: 21422933)
2. Wathen JE, Gao D, Merritt G, Georgopoulos G, Battan FK. A randomized controlled trial comparing
a fascia iliaca compartment nerve block to a traditional systemic analgesic for femur fractures in a
pediatric emergency department. Ann Emerg Med. 2007 Aug;50(2):162-71. (PMID: 17210208)
3. Haines L, Dickman E, Ayvazyan S, Pearl M, Wu S, Rosenblum D, Likourezos A. Ultrasound-guided
fascia iliaca compartment block for hip fractures in the emergency department. J Emerg Med. 2012
Oct;43(4):692-7 (PMID: 22494596)
A210
AN UNUSUAL CASE OF ASIA C T-10 PARAPLEGIA AFTER LUMBAR TRANSFORAMINAL
EPIDURAL STEROID INJECTION
H. Kalia, J. Kent
Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA
Introduction: Epidural Steroid Injections have been used widely to manage both axial low back and
radicular leg pain for more than 30 years. Fluoroscopically guided epidural injections carry an overall
1
complication rate of 0% - 9.6%. Although Paraplegia following a transforaminal injection is extremely
rare; it has been reported in the literature.
Case description: Mrs.S is a 59 y/o F with past medical history significant for SVT,depression,
hypothyroid, GERD, undifferentiated connective tissue disorder, renal cell carcinoma status post left
partial nephrectomy in 2010 and Significant spinal stenosis. Her baseline segmental pathology as
elucidated through an MRI is as follows: 1) Moderate Right L1-2 foraminal stenosis 2) 5mm synovial
cyst at left L1-2 facet joint 3)Mod Right L2-3 foraminal stenosis. 4) Severe right L3-4 foraminal
stenosis with facet arthropathy. 5) Diffuse disc osteophyte complex abutting left L5 & L4 nerve root. 6)
Severe Left and moderate right L4 foraminal stenosis. 7) Severe Left L5 foraminal stenosis. 8)
Scoliosis.
Patient was scheduled for Left L4 and L5 transforaminal steroid injections due to her predominant
radicular leg pain along the Left L4/ L5 dermatomal distribution. 6ml”s of 1% lidocaine was used to
infiltrate the skin. A 22-gauge 5 inch spinal needle was advanced into the cephalad aspect of the
“safe triangle”. Both roots were targeted lateral and caudal to the standard approach due to significant
osteophytes. After the needle tip was confirmed on both AP and lateral images; and, aspirate was
negative for CSF and heme; 3ml Omnipaque 240mg/ml was used to ascertain the placement. There
was no vascular or intrathecal spread of contrast. 50 mg of methylprednisone acetate and 1 mL of 1%
lidocaine was injected at each level. Patient instantaneously developed paraplegia following the
injections. Her initial examination was consistent with ASIA-C T-10 paraplegia. MRI with contrast
within 24hrs and 48hrs were negative for any ischemic cord injury or subdural hematoma. Patient
recuperated most of her motor and sensory deficits on the right side over the course of next 48hrs but
her recovery pattern on the right side remained protracted. She continued to make neurological and
functional gains over the next 14 days.
Discussion: There are total 12 cases of paraplegia reported in literature following an epidural steroid
injection. We hereby report the only case of transient paraplegia which resolved over the course of 15
days. Interestingly, the only minor deficits which prevail in our patient are motor strength 4/5 in Left
Hip flexors and diminished pin prick and light touch below Left L4 dermatome. Patient”s clinical
presentation and recovery pattern fail to justify any particular theoretical explanation. Her recovery
pattern precludes a possibility of intrathecal or subdural injection. A plausible explanation ranges from
vascular spasm, intravascular injury to a possibility of “double crush syndrome” where- in her baseline
significant spinal pathology predisposed her to develop spinal cord injury following an epidural
injection.
Reference:
1. Houten, J. K., & Errico, T. J. (2002). Paraplegia after lumbosacral nerve root block: Report of three
cases. The Spine Journal, 2(1), 70-75.
A211
SACRAL AND THORACIC NERVE STIMULATION FOR A COMBINED EFFECTIVENESS ON THE
TREATMENT FOR CHRONIC TESTICULAR PAIN
S.S.W. Kim, T. Edala, M. Patel, A. Ghaleb
Anesthesiolgy, University of Arkansas for Medical Sciences, Little Rock, AR, USA
Chronic testicular pain is becoming a more common problem. Due to the numerous potential
etiologies, it can often be frustrating and time consuming to both the physician and the patient. One of
the more common causes of chronic testicular pain is post vasectomy pain which has been reported
to range from 15-19% but may be up to 52%. Recently there has been increased interest in spinal
cord stimulation as an alternative treatment for chronic testicular pain. Previous case reports of nerve
stimulations of both the sacral nerves and of the dorsal columns of the thoracic nerves has given
promising results. McJunkin et al. has described testicular pain reduction of 80% with sacral nerve
stimulation and Nouri et al. reported a reduction of VAS scale score from 5/10 to 1/10. However, in
our case we were able to look at both sacral and thoracic stimulations independently and as a
combined effect. Because we implanted two separate leads, our patient was able to independently
control stimulations in both areas. He reported that although separate lead stimulation produced relief,
it was the combined effect that gave him the greatest reduction to pain of at least 75%. Due complex
and significant overlap of the innervations of the scrotal content we were able to demonstrate that the
combined effects of SCS on both lumbar and sacral nerves may provide better relief in patients
refractory to SCS of either lumbar or sacral nerves.
A212
DELAYED ONSET OF SYMPTOMATIC PHRENIC NERVE BLOCK AFTER INTERSCALENE
BRACHIAL PLEXUS BLOCK IN A MIDDLE-AGED PATIENT
K. Candido, Y. Slota, N.N. Knezevic
1
2
Anesthesiology and Pain Medicine, Advocate Illinois Masonic Medical Center, Anesthesiology,
University of Illinois at Chicago, Chicago, IL, USA
Introduction: The incidence of phrenic nerve blockade following interscalene brachial plexus block
approaches 100% unless very modest of local anesthetics are injected using ultrasound guidance.
However, the majority of patients remain asymptomatic by recruiting accessory respiratory and
1
abdominal muscles. The onset of symptoms generally correlates with the pharmacological properties
of the local anesthetic used for the block. We report a case of a symptomatic phrenic nerve blockade
developing five hours after the onset of the sensory nerve blockade in a 42 year-old patient
undergoing elective shoulder surgery under combined regional block-general anesthesia.
Case description: A 42 year-old male patient with a history of multiple right shoulder surgeries and
2
BMI of 33 kg/m presenting with right shoulder impingement syndrome was scheduled for right
shoulder arthroscopy and open acromioplasty. The patient was consented for right interscalene
brachial plexus block for post operative analgesia, and surgery was performed under general
anesthesia. Ultrasound was used to locate the proximal trunks of the plexus. At a depth of 1.5 cm, a
0.4 mA deltoid twitch was elicited and 30 mL of 0.5% ropivacaine was incrementally injected in the
preoperative nerve block area. Complete sensory block was successfully obtained after 30 minutes
and the patient denied respiratory symptoms. The baseline SpO2 did not decrease from 98% in the
first 45 minutes following block completion. The respiratory rate varied between 14 and 18
breaths/minute during this time period. The patient was taken to the OR and general anesthesia was
induced without complications. Only 50 mcg of fentanyl were used as adjuncts to anesthesia and the
trachea was extubated after full reversal of muscle relaxants at the completion of the 1.6 hour surgery.
The patient remained pain free and asymptomatic in the PACU, and he was transferred to the floor.
The patient complained of chest discomfort and dyspnea, five hours post block. The S pO2 on room air
was noted to be 92% and the respiratory rate was 26/minute. Cardiac and pulmonary workup did not
reveal any abnormalities. A chest X-ray demonstrated evidence of right diaphragmatic hemiparesis
consistent with unilateral, ipsilateral right phrenic nerve blockade.
[Figure 1]
The patient was reassured and kept on supplemental oxygen throughout
the night. The following morning, the phrenic nerve block resolved and the dyspnea was eliminated.
Conclusion: Respiratory symptoms related to phrenic nerve blockade are usually expected to
correlate with motor block onset. In 2006, Delcourt et al. reported three cases of delayed respiratory
symptoms in geriatric patients after nerve-stimulator ISB with approximate onset of 2-3 hours after
2
block completion. This case report is unique in that the onset was 5 hours after ultrasound ISB in a
middle-aged patient. This report should raise awareness of the possibility of delayed respiratory
symptoms in virtually any patient being provided an ISB using volumes conventionally employed in
common clinical practice.
References:
1. Verelst, P. et al. Reg Anesth Pain Med 2011;36:411-2.
2. Delcourt, J. et al. Can J Anaesth 2006;53:110-1.
A213
INCIDENTAL FINDING OF A HEMATOMA DURING FEMORAL NERVE BLOCK
S.H.P. Kolli, H.K.P. Kalagara, K. Maheshwari, E. Farag, M.L. Soliman
Anesthesiology, Cleveland Clinic, Cleveland, OH, USA
Objective: To report a case of inguinal hematoma complicating the anatomy and performance of a
femoral nerve block.
Case report: A 64 year old lady scheduled for total knee arthroplasty was consented for a continuous
femoral nerve block for post-operative pain relief. On ultrasound examination the anatomy was
distorted due to the presence of a large hypo-echoic structure medial to the nerve with a very small
artery.
Discussion: Ultrasound guidance for regional anesthesia is an evolving field. With the increased use
of this technology by our community, atypical and even pathologic anatomy may be revealed.
Conclusion: The Ultrasound was useful not only to identify but avoid the hematoma while performing
the block. We can expect to come across more similar situations given the increased use of
ultrasound. Hence this reemphasizes the need for the training in ultrasound to incorporate the ability
to appreciate the common non neural pathology.
A214
CONTINUOUS INTERSCALENE NERVE BLOCK FOR PALLIATIVE MANAGEMENT OF
INTRACTABLE PAIN FROM BRACHIAL PLEXOPATHY ASSOCIATED WITH PANCOAST TUMOR
M. Koski, K. Maheshwari, W. Ali Sakr Esa, A. Rao
1
2
General Anesthesia, Palliative Medicine and Supportive Oncology, Cleveland Clinic Foundation,
Cleveland, OH, USA
Introduction: The incidence of painful brachial plexopathy in all cancer patients is 0.4%. It is often
difficult to treat with conventional analgesics including opioids which offer suboptimal relief .We report
a patient with intractable brachial plexopathy successfully managed with an interscalene peripheral
nerve block in hospice reducing the need for recurrent admissions for pain control.
Patient History: A 41 yr old female presented with left upper extremity pain radiating to the axilla and
no Horner´s syndrome. A superior sulcus cancer (Pancoast tumor) arose from her left upper lobe. Her
pain was managed with a combination of hydromorphone and methadone, amitriptyline and naproxen
which were continuously titrated up over 2 months with minimal relief. She subsequently underwent a
left upper lobectomy with en bloc resection of ribs 1 through 4, mediastinal lymphadenectomy and
chest wall reconstruction. She was deemed hospice appropriate. Over a few months she was
admitted on 4 occasions with severe pain. Cryoablation, high dose hydromorphone PCA,
ethosuximide, ketamine and palliative sedation were attempted without success. An interscalene
peripheral nerve catheter was inserted subsequently with continuous infusion of ropivacaine 0.2% at a
basal rate of 10ml/hr and 10 ml demand dose every 60 min and following this patient´s pain was
better controlled (decreased from severe to mild). Hydromorphone dose in the PCA was decreased
significantly and she was able to be weaned from methadone. She did not need readmission.
Discussion: Continuous nerve blocks relieve brachial plexopathy pain in lung cancer. Regional
blocks are preferable to destructive procedures such as cordotomy and decrease the need for
opioids. Multiple reasons like cost, awareness among providers , infection risk with prolonged block,
lack of specialised team for performing blocks and follow up may present as barrier leading to
underuitilization of regional nerve blocks while in hospice. These challenges for considering regional
blocks needs to be weighed against suboptimal pain control and readmissions .
Conclusion: Interscalene regional blocks reduce refractory brachial plexopathy pain and should be
considered as an option for pain management.
References: Buchanan, D etal. Outpatient Continuous Interscalene Brachial Plexus Block in CancerRelated Pain. Journal of Pain and Symptom ManagementVolume 38, issue 4, p. 629-634. October,
2009.
[MRI C spine. Paraspinal mass on the left extending]
A215
PULMONARY HYPERTENSION DURING PREGNANCY: A CASE PATIENT MANAGED WITH AN
INTRATHECAL BUPIVACAINE INFUSION FOR CESAREAN SECTION
J. Kwan, D. Nguyen, C. Martinello, A. Singal, A. Van, E. Hurwitz
Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
Pulmonary hypertension in pregnancy, a relatively uncommon condition, is associated with significant
morbidity and mortality for the parturient. The physiologic changes of normal pregnancy may include
abrupt fluid shifts and considerable increases in cardiac output and plasma volume with reduction of
systemic vascular resistance. While these demands are usually well tolerated by the otherwise
healthy parturient, pulmonary hypertension in the setting of pregnancy places the patient at significant
risk for life-threatening right ventricular failure and hemodynamic collapse. Planning and vigilant
management of this condition is of particular importance during parturition and the postpartum period.
We present a case of a 37-year-old term pregnant African American woman with severe pulmonary
hypertension based on right ventricular systolic pressure exceeding 60 mm Hg on transthoracic
echocardiography. A right heart catheterization confirmed the findings on echocardiography. Her
additional comorbidities include moderate mitral stenosis with regurgitation, diabetes mellitus type II,
history of rheumatic heart disease, morbid obesity with a BMI greater than 45, and three previous
cesarean sections. The patient reported occasional clinically significant dyspnea during pregnancy
and also with exertion.
The anesthesiology service had decided on specific monitoring and interventions for the day of the
planned cesarean section. Our management for the patient included an arterial catheter placed prior
to the procedure for hemodynamic monitoring in addition to standard monitors. Based on a literature
review conducted by our team, the use of pulmonary artery catheterization is generally used on a
case-by-case basis. After extensive discussion between multiple specialties including cardiology,
pulmonology, obstetric maternal-fetal medicine, and anesthesiology, it was ultimately determined that
an intraoperative pulmonary artery catheter may not improve diagnostic value based on her known
symptoms. Additional preparation included having a fluid warmer with a rapid infusion setup and
blood products immediately available in the room. In our case patient, we also utilized phenylephrine,
albumin, and blood transfusions as clinically indicated by vital signs and clinical symptoms. Other
pharmacological agents immediately available were milrinone, sildenafil, dobutamine, epinephrine,
and epoprostenol. Our initial analgesic management for the scheduled cesarean section planned for
an epidural catheter with slow titration to an appropriate level of surgical anesthesia. During attempted
epidural catheter placement by another anesthesiologist, an unintentional dural puncture occurred,
which was confirmed with cerebrospinal fluid return. Consequently, an intrathecal catheter was
utilized instead. The patient was managed with an intermittent intrathecal titration of hyperbaric 0.75%
bupivacaine and preservative-free morphine and did not suffer any complications intraoperatively.
Postoperatively, blood transfusions with appropriate fluid resuscitation were administered via a right
internal jugular central venous catheter and titrated to clinical symptoms and response. The patient
recovered well and was ultimately discharged four days post-procedure.
Pulmonary hypertension during pregnancy is a rare condition that can be associated with significant
morbidity and mortality. Treatment often requires individualization for each patient presentation.
Further research on parturients with pulmonary hypertension will likely be beneficial to determine
optimal treatment algorithms that also include neuraxial anesthesia and analgesia for this patient
population.
A216
EPIDURAL ANESTHESIA FOR THE TREATMENT OF LOWER EXTREMITY ISCHEMIA
FOLLOWING AORTIC ENDOVASCULAR SURGERY: A CASE REPORT
L. Lahaye
Virginia Commonwealth University, Richmond, VA, USA
Introduction: Management of lower limb ischemia in the setting of recent aortic endograft placement
is dictated by the inciting factors. We present a case of lower extremity arterial insufficiency following
endovascular aortic repair that resolved with the induction of regional anesthesia with epidural local
anesthetic.
Case report: A 60 year old female with a medical history significant for hypertension, COPD, chronic
pain and tobacco abuse was transferred to our hospital with radiographic findings of a contained
rupture of her abdominal aorta. The patient had a two day history of severe abdominal and back pain
and a CT study demonstrated involvement of the infrarenal abdominal aorta.
On the morning of surgery, a thoracic epidural catheter was placed in the pre-operative holding area
however was not used during case at the request of the surgeon in favor of a general technique. The
aorta was accessed via bilateral groin sheaths. Two grafts were deployed, one extending from the
distal margin of the left renal artery and a second intussuscepted within the first to the aortic
bifurcation. Completion angiography demonstrated preservation of both common iliac and renal
arteries as well as complete exclusion of the aorta proper.
Post-operatively the patient was admitted to the Intensive Care Unit with the epidural catheter in situ
without infusion. All distal pulses were confirmed intact by bedside Doppler. Thirty minutes later the
patient complained of left lower extremity pain and coolness and was found to have a mottled limb
below the knee with Doppler signals lacking distal to the femoral artery. Vascular access sites
appeared externally normal. Formal duplex and color flow ultrasound studies demonstrated
monophasic waveforms distal to the external iliac artery suggesting a proximal obstruction. The
patient was transported to the holding area in anticipation of urgent angiography and thrombectomy.
At that time the patient's epidural was bolused with 2% lidocaine to achieve a T10 level of anesthesia
after which she was transferred to the operating room. Upon arrival, the patient was re-evaluated and
found to have palpable femoral, popliteal and posterior tibial pulses which were conformed present
with Doppler.
Discussion: Epidural sympatholysis has been described as part of multi-modal treatment for patients
with severe, limb threatening lower extremity ergotamine induced vasospasm (1). Continuous
sympathetic blockade with epidural analgesia has also proven beneficial in severe cold injury of the
lower extremities. Other forms of sympatholysis have been used for patients with vasospastic
pathology including Raynaud's disease (2). Given the rapid reversal of our patient´s arterial
insufficiency following epidural induction, the diagnosis of thrombotic or embolic occlusion was
unlikely. Epidural anesthesia may be considered in treating lower extremity vasospasm following
major vascular surgery.
References:
1. Demir, S et al. Diagnostic Interventional Radiology 2010; 16: 165-167
2. Rizzo, M et al. Orthopedics 2004; 27(1): 49-52
A217
ASSESSING PERIPHERAL NERVE CATHETER PLACEMENT THROUGH THE USE OF
ULTRASOUND COLOR FLOW DOPPLER
A. Lange, E. Joe
Anesthesiology, University of Maryland, Baltimore, MD, USA
Introduction: Many patients benefit from continuous peripheral nerve blockade (CPNB) due to
prolongation of the benefits of regional anesthesia beyond the maximum duration of a single injection.
For CPNB to be effective, the catheter must be appropriately positioned. Ultrasound visualization of
the catheter itself is often challenging. Several methods have been described to verify the position of
the catheter indirectly, including direct ultrasound visualization of injectate spread, use of agitated
contrast, and looking for tissue movement upon insertion. While useful, none are capable of
identifying the catheter position with 100% success. Thus, we present an additional method that is
easy, time-efficient, and safe. We report a case where ultrasound Doppler flow was used to accurately
visualize the anatomic position of drug delivery and verify proper positioning of the perineural catheter
when other modalities failed.
Methods: This report involves a 53-year-old scheduled for rotator cuff repair under interscalene
blockade. A 12L probe was used for visualization, and an 18 gauge Tuohy was positioned just
posterior to the brachial plexus. 20mL of ropiviciane was injected incrementally to facilitate onset, and
was seen to appropriately surround the plexus. A 20 gauge catheter was easily inserted through the
Tuohy. Tissue movement during catheter placement under ultrasound suggested an appropriate
catheter placement. However, the actual catheter tip position was unclear. Additional anesthetic was
injected, but accumulation was difficult to detect. Injection of an agitated solution was also ineffective
at providing satisfactory confirmation. Colorflow Doppler was then applied to the area, and the
catheter was injected in a pulse-like pattern. Doppler activity confirmed injectate appropriately
surrounding the brachial plexus (Figure 1).
[Figure 1]
Results: The patient achieved excellent sensory and motor blockade. He was taken immediately to
the operating room and underwent surgery under interscalene block with IV sedation. The patient
denied any pain in the PACU and had an uneventful discharge home with an infusion pump. The
patient was contacted via phone, and he reported continued excellent pain relief and sensory
blockade in his shoulder. Infusion was completed by POD 3 and the catheter was removed by the
patient without complications.
Discussion: Detection of the final position of a peripheral nerve catheter is sometimes challenging
due to small injectate volumes, high catheter resistance, previously-injected solution, and difficulty
visualizing the catheter itself. The use of ultrasound-guided colorflow Doppler as an additional tool to
assess the spread of anesthetic via peripheral nerve catheter was valuable in this case where spread
of the anesthetic was otherwise hard to visualize. This prevented the repositioning or replacement of
a catheter that was in the appropriate position. This report suggests that the use of ultrasound
colorflow Doppler may be a valuable tool in detecting the placement of a peripheral nerve catheter.
There is no additional risk to the patient and the technique requires minimal additional time.
References:
Richman JM, et al. Does CPNB provide superior pain control to opioids? A meta-analysis.
AnaesthAnalg2006;102(1):248-57
Ilfeld BM. CPNBs: a review of the published evidence. AnesthAnalg2011;113:904-25
A218
LOCAL ANESTHETIC SYSTEMIC TOXICITY (LAST) IN AN ESKD PATIENT UPON RECEIVING
AN AXILLARY BRACHIAL PLEXUS BLOCK ALONG WITH BLOCKS OF THE
MUSCULOCUTANEOUS & INTERCOSTOBRACHIAL NERVES
J. Li, R. Wardhan
Anesthesiology, Yale University, New Haven, CT, USA
In ASA closed claim cases, LAST accounts for 1/3 of deaths or brain damage associated with
regional anesthesia, 93 events have been published in past 30 years. We report a case, where a
mixed ropivacaine and lidocaine solution caused CNS depression, with further progression interrupted
by the administration of Intralipid. A 57-year-old African woman was scheduled for placement of an
upper arm AV fistula. Patient's past medical history was significant for End Stage kidney disease, HIV
on HAART, HCV, Schizophrenia, Asthma, COPD & pulmonary fibrosis.On physical exam, patient
seemed to be well optimized for surgery, had a normal BMI and lab work was reflective of her comorbidities.On arrival to the OR, the patient's oxygen saturation was 93% on 2L of oxygen by nasal
cannula. Patient received 1 mg of midazolam and 50 mcg.The block was placed in the OR, under
ultrasound guidance. An axillary brachial plexus block was planned in hopes of avoiding phrenic
nerve palsy. A total of 30 cc of local anesthetic was used consisting of 15 cc of 0.5% Ropivacaine and
15 cc of 2% Lidocaine.An intercostobrachial nerve block was done using 5cc of 2% lidocaine. Direct
needle visualization was achieved with ease and patient was cooperative during the entire procedure.
It was during the local infiltration of lidocaine for intercosto brachial nerve, that patient started
complaining of severe pain. Roughly two minutes later, patient became increasingly somnolent and
was difficult to arouse. All the vital signs were stable, no EKG changes were noted, oxygen saturation
was now noted to be a 100% without any change in FiO2. Pupils were responsive to light, but did
appear to be pinpoint. The differential diagnosis at that point was oversedation vs LAST. A total of 80
mcg of Naloxone was administered but no improvement was noted. At this point ,a bolus of Intralipid
75ml was administered. Soon after completion of the bolus patient started to wake up but appeared to
be confused and agitated displayed some myoclonic. Another 1mg midazolam and 30mg propofol
were administered. Patient became progressively unresponsive again.Surgical procedure was
cancelled and the intralipid infusion was restarted. The patient slowly regained her baseline mental
status. About 2.5 hours after the nerve block was placed, patient returned to her baseline mental
status and a complete neural exam was intact. An emergent CT of the head was performed to rule out
any CNS events, which was later found to be normal.
Discussion: Risk factors for LAST in this patient were poor functional/ASA IV status, ESKD. Although
aspiration of local anesthetic was done during injection, but it has not been proven to be a 100%
preventive. Even though the needle tip was visualized during the entire procedure, it's unclear, at
which point, the vascular injection occurred. The symptoms of LAST can be subtle & do not always
consist of seizures and /or cardiac arrhythmias. Since LAST is more common than we may think and
an effective prevention is not currently available,high clinical suspicion and immediate treatment may
be the key.
A219
GABAPENTIN AS A CAUSE OF HEPATOTOXICITY
S. Mian, H. Rana
Anesthesiology and Pain Management, University of Texas Southwestern Medical School, Dallas, TX,
USA
The treatment of lumbar radicular pain is difficult and the effective non-surgical treatments available
are limited. Previous studies have shown that gabapentin is an effective conservative therapy for both
acute and chronic radicular pain secondary to lumbar degenerative disc disease. Gabapentin is
considered to be a safe, cost-effective adjunct in treating neuropathic pain syndromes.
We present a case of a 51 year old female with a past medical history significant for chronic low back
pain, HIV, hypertension, chronic hepatitis C, and Diabetes Mellitus. In June of 2011, during a routine
followup to her primary care physician, our patient complained of diffuse pruritus. She was initially
given symptomatic treatment and had her labs checked. Her lab work revealed a significant
transaminitis. At this time her medications included glyburide, metformin, gabapentin, baclofen,
Truvada, Darunavir, aspirin, trazodone, and ritonavir. She has been on her HAART regimen for years.
The gabapentin was recently added 2 months prior and titrated up to a dose of 600mg three times
daily. Her initial workup included a right upper quadrant ultrasound and lab work. Her ultrasound
showed no cirrhosis. Her lab work was negative for ANA, LKMI antibody, mitochondrial antibody, RF,
and smooth muscle antibody. Additional workup subsequently included a liver biopsy in July of 2011.
This revealed an acute inflammatory process consistent with drug-induced liver injury. Her hepatitis at
this point was considered stage 1, grade 3. Her physicians then took her off of glyburide, metformin,
and gabapentin with frequent lab work. Her liver enzymes slowly trended downward after these
medication changes.
She was seen in our clinic in November of 2012 for her chronic low back and radicular pain. Her
imaging revealed lumbar degenerative disc disease, mild lumbar spinal stenosis, and S1 nerve root
compression. She stated that the gabapentin helped her pain significantly in the past and her previous
physicians were unsure which medication caused her transaminitis. After a thorough literature search,
we decided to trial gabapentin, starting at 300mg three times daily and check her liver function
enzymes in 6 weeks. No other medication changes were made during this period. Her subsequent
labs revealed a transaminitis with elevation of her AST in particular. We stopped her gabapentin once
again and plan on re-checking her labs in 1-2 weeks. We anticipate her liver function tests to be
normalized.
To the best of our knowledge this is the first reported case of gabapentin induced hepatotoxicity.
Gabapentin should be added to the list of drugs capable of producing this adverse reaction.
Funding: None.
Competing interests: None declared.
References:
Tremont-Lukats IW, Megeff C, Backonja M. Anticonvulsants for neuropathic pain syndromes. Drugs
2000; 60:1029-52
Richardson CE, Williams, DW, Kingham, JG. Gabapentin induced cholestasis. BMJ. 2002; 325: 635
Hsu VD, Alemayehu S, Barry E. Gabapentin induced hepatotoxicity. Int Pharm Abstr. 1995; 32:794
Lasso-de-la-Vega MC, Zapater P, et al. Gabapentin-associated hepatotoxicity. Am J Gastroenterol.
2001, 96:3460-3462.
Yildrim K, Deniz O, et al. Gabapentin monotherapy in patients with chronic radiculopathy: the efficacy
and impact on life quality. J Back Musculoskelet Rehabil. 2009;22(1):17-20
A220
“HIGH-RISK OUTPATIENT SURGERY” AND THE BENEFITS OF REGIONAL ANESTHESIA,
EVEN IN PATIENTS ON ANTIPLATELET THERAPY
C. Moore, N. Hanson, D. Auyong
Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA
Introduction: Arthroscopic shoulder surgery is considered a safe outpatient procedure. However, the
beach chair position in which it is performed increases risk of morbidity compared to supine
positioning. Associated complications, including strokes, have been reported even in healthy
patients[1]. Regional anesthesia can be beneficial by reducing opioid-related side effects
postoperatively. ASRA guidelines advise withholding clopidogrel 5-7 days prior to surgery, but do not
offer much guidance regarding procedures during continued antiplatelet therapy[2]. Anesthesiologists
often face these situations not addressed by guidelines where they must weigh risks and benefits of
performing regional anesthesia in anti-coagulated patients with multiple comorbidities. Often, this
limits regional techniques to “easily compressible” or “less traumatic” techniques to avoid hematomas
or vascular injury.
Case: A 79-year-old male presented for outpatient arthroscopic rotator cuff repair in the beach-chair
position. Pertinent medical history included hypertension, GERD, diabetes, prior TIA, and
acetaminophen allergy. Blood pressure was 184/86, above his baseline systolic of 160mmHg. A
recent MRI showed multiple high-grade stenoses not amenable to treatment. For this he was placed
on clopidogrel, which he continued for the procedure. Due to his clopidogrel use, no pre-operative
brachial plexus block was performed. After detailed risk/benefit discussion with the surgeon and
patient, it was decided to proceed with general anesthesia for surgery. A radial arterial-line was
placed to accurately maintain blood pressure near baseline. The case was completed without
immediate complications and intravenous hydromorphone was dosed for nociception.
Post-operative management: In the PACU, he complained of severe shoulder pain unresponsive to
opioids and became nauseated and confused shortly after administration. Per pre-operative
discussion, a “rescue” single-shot interscalene brachial plexus block was performed. During
ultrasound pre-scan, the dorsal scapular artery was noted to be directly posterior to the brachial
plexus and in the path of a standard in-plane posterior needle approach. Therefore, an out-of-plane
approach was used to avoid any vasculature and resulted in immediate analgesia. Despite ongoing
use of clopidogrel, this interscalene block allowed the patient to be sent home with superior analgesia,
preventing unexpected hospital admission for intractable pain. Upon follow-up, the patient reported
good analgesia for >12 hours, but noted significant discomfort from the initial opioid side effects.
Discussion: With uncontrolled hypertension in the setting of prior TIA, our patient underwent surgery
in the beach chair position, placing him at risk of repeat stroke. Management may have been
improved by using regional anesthesia and multimodal analgesics. Though there is literature
highlighting the opioid-reducing benefits of regional anesthesia, little addresses performance of
regional anesthesia in the setting of antiplatelet agents. With the use of ultrasound-guided regional
anesthesia, vascular structures can sometimes be identified and avoided, but in the absence of large
studies on individual anticoagulants to guide us, clinical judgment on individual cases must be used.
In this case, regional anesthesia allowed us to avoid an unplanned hospitalization, and could likely
have prevented a prolonged PACU stay if placed pre-operatively.
References:
1. Pohl and Cullen. J Clin Anes 2005; 17:463-9.
2. Horlocker et al. RAPM 2010; 35:64-101.
A221
SUCCESSFUL TREATMENT OF ILIOINGUINAL NEUROPATHY AFTER ROBOTIC-ASSISTED
LAPAROSCOPIC SACROCOLPOPEXY WITH ULTRASOUND-GUIDED NERVE BLOCK
A.R. Moraska, S. Zaky
Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
Background: Intraoperative injury to the ilioinguinal nerve is commonly described as a complication
of inguinal herniorrhaphy. However, it is not typically thought of with laparoscopic gynecologic
surgery. Ilioinguinal nerve block, with or without ultrasound guidance, has well documented success
in alleviating ilioinguinal neuropathic pain (1, 3). The following case describes ilioinguinal neuropathy
after robotic-assisted laparoscopic sacrocolpopexy, for which a single shot ilioinguinal nerve block
provided lasting pain relief.
Case: A 45 year-old woman, with a history of hypertension, gastric bypass, and L5 disc herniation,
underwent robotic-assisted laparoscopic sacrocolpopexy for vaginal prolapse. Three robotic ports
were placed: above the umbilicus, and 10cm lateral to midline in the LLQ and RLQ. Surgery was
uneventful. Immediate post-operative pain was managed with a fentanyl PCA and ketorolac. She was
discharged home on POD #1. On POD #4, she called complaining of pain that was “constant, sharp
and burning in nature, worse with movement, like barbed wire being pulled through her skin” from her
right side, under the RLQ port incision, to her pubis. The pain continued to worsen. On POD #5 she
presented to the ED and was admitted for pain control.
Initial trigger point injection with bupivacaine and triamcinolone provided only mild, transient pain
relief. Anesthesia Acute Pain Management Service was consulted and performed an ultrasoundguided single shot ilioinguinal nerve block with 20 mL 0.75% ropivacaine and 6 mg dexamethasone
(images below). The patient experienced immediate and complete pain relief. She was discharged
home and at 2-week and 1-month follow-up, she reported no pain at rest and only mild, intermittent
discomfort with movement.
[Ultrasound image, ilioinguinal nerve before block.]
[Ultrasound image, after injection of ropivacaine.]
Discussion: Ilioinguinal neuropathy after laparoscopic gynecologic surgery may be more common
than thought. A recent study showed 2% of 317 cases from 2008-2011 resulted in significant
ilioinguinal/iliohypogastric neuropathic pain requiring treatment (2). All cases with nerve injury had
fascial closure of the laparoscopic port site, suggesting surgical technique plays an important role.
Regardless, this case highlights the benefit of early intervention with regional anesthesia for acute
postoperative neuralgia. Unfortunately, these highly effective techniques are often used only after
parenteral and oral analgesics, which carry greater side effect profiles, have failed or when the pain
becomes chronic. Earlier treatment with nerve blocks in these patients could lead to not only improved
patient satisfaction and quality of life, but may also decrease progression to chronic neuralgia.
References:
1. Finnerty O, et al. Trunk blocks for abdominal surgery. Apr 2010. Anaesthesia; 65 Suppl 1:76-83.
2. Shin JH and Howard FM. Abdominal wall nerve injury during laparoscopic gynecologic surgery:
incidence, risk factors, and treatment outcomes. Jul-Aug 2012. J Minim Invasive Gynecol; 19(4):44853.
3. Thomassen I, et al. Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks for chronic pain after
inguinal hernia repair. Sep 27, 2012. Hernia. Epub.
Funding: none.
Conflict of interest: none.
A222
SUPRASCAPULAR PERINEURAL CATHETER FOR POST-OPERATIVE SHOULDER ANALGESIA
M. Moretto, D. Auyong
Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA
A 43 year old 133 kilogram male was scheduled for left arthroscopic open rotator cuff repair and distal
2
clavicle resection. Comorbidities included obstructive sleep apnea, active smoker, BMI of 42 kg/m ,
and chronic opioid use. A similar procedure was performed on his right shoulder two years earlier.
Prior anesthetic management included a general anesthetic with interscalene block. In the PACU, the
patient had dyspnea, diminished ipsilateral breath sounds, and desaturations to the 80's. He was
eventually stabilized and discharged home, but then readmitted to the hospital later that evening for
hypoxia and aspiration pneumonia. The patient recovered from his post-operative complications.
With knowledge of prior difficulty, we performed a suprascapular perineural catheter for his current
surgery. The suprascapular nerve was identified exiting from the superior trunk of the brachial plexus.
A perineural catheter was placed under ultrasound guidance next to the suprascapular nerve. Fifteen
milliliters of lidocaine 1.5% was dosed through the catheter. Thirty minutes later, no symptoms of
dyspnea were noted and an infusion of 6 mL/hr of ropivacaine 0.2% was started. The surgery was
completed under general anesthesia without complication. In the PACU, the patient reported good
analgesia with no opioid requirement. SpO2 remained >97% and the patient was discharged home
one-hour post operatively with the suprascapular perineural catheter. On post-operative follow-up, the
patient reported excellent analgesia with subjective pain scores < 2 /10 with no dyspnea or other
complaints. The catheter was discontinued by the patient on post-operative day two without
complication.
The suprascapular nerve originates from C5 root or upper trunk of the brachial plexus. It provides up
to 70% of the afferent fibers from the shoulder and the overlying skin (1). This nerve can be identified
with ultrasound as a hypoechoic structure exiting laterally from the C5 nerve root / upper trunk as the
transducer is moved caudally from the interscalene level.
It is well known that interscalene brachial plexus blockade provides post-operative analgesia for
shoulder surgery (2); however, the incidence of ipsilateral hemi-diaphragmatic paresis is nearly
100%(3). Hemi-diaphragmatic paresis is significantly less with supraclavicular block, about 50% (2).
Typically, supraclavicular catheters are not recommended for shoulder surgery as these blocks are
performed distal to the exit of the suprascapular nerve (2), important in shoulder innervation. A
selective suprascapular catheter could provide the desired analgesia with even less risk of phrenic
nerve blockade, as these blocks are performed more laterally.
This patient undergoing shoulder surgery presented a challenge for post-operative analgesia due to
his chronic opioid use and obesity / restrictive lung disease with previous inability to tolerate phrenic
nerve paralysis from an interscalene nerve block. Placement of a suprascapular perineural catheter
provided shoulder analgesia with no clinical evidence of hemi-diaphragmatic paresis. This case
illustrates a technique to provide effective post-operative shoulder analgesia to a patient with
pulmonary dysfunction and chronic opioid use.
1. J Shoulder Elbow Surg 2008;17:500-502.
2. Regional Anesthesia and Acute Pain Management 2007;403- 425.
3. Anesth Analg 1991;72:498 - 503.
[Suprascapular Nerve]
A223
DUM SPIRO, SPERO: USE OF CONTINUOUS THORACIC PARAVERTEBRAL BLOCKADE AND
DEXMEDETOMIDINE INFUSION FOR ANALGESIA IN A CHILD WITH METASTATIC
OSTEOSARCOMA AND POSTOPERATIVE DELIRIUM
L. Le-Wendling, A. Munro
Anesthesiology, University of Florida, Gainesville, FL, USA
Introduction: One of the less studied but increasingly frequent challenges in pain medicine is the
pediatric patient with chronic pain who then presents with severe postoperative pain. Even more
difficult is the analgesic management of a pediatric patient with acute pain and postoperative delirium.
Regional anesthesia, selective multimodal analgesics, and a multidisciplinary approach are required
to achieve optimal care.
Case presentation: A 13 y.o. male with a history of neuroblastoma and radiation-induced left pelvic
osteosarcoma presented with a small bowel obstruction that required small bowel resection with
primary anastomosis. The patient had been on chronic analgesics that included baclofen 10mg per os
(PO) three times daily, methadone 40mg PO twice daily, oxycodone 15MG PO every 6 hours as
needed and pregabalin 200mg PO three times daily. Despite multiple adjustments to his opioid
patient-controlled analgesia, the patient reported no relief in his severe abdominal pain from his
surgery as well as hallucinations. The Regional Anesthesia and Perioperative Pain Management
Service was consulted. Because of thrombocytopenia, bilateral thoracic paravertebral catheters were
placed instead of a continuous epidural catheter. Due to his worsening postoperative delirium, a
dexmedetomidine infusion was utilized for further analgesia allowing the intravenous fentanyl infusion
to be weaned to a lower basal rate. The use of seroquel and midazolam led to a resolution of the
delirium.
Discussion: This case highlights many important issues in acute on chronic pain management in the
pediatric patient: the importance of using a multimodal technique for pain management, the utility of
bilateral paravertebral catheters for postoperative somatic pain in a patient with coagulation
abnormalities, and the difficulties in medication selection when managing pain in a pediatric patient
with postoperative delirium. Furthermore, uncontrolled pain in childhood can lead to problems with
emotional wellbeing and academic achievement, increase the risk for developing depression and
anxiety, and predispose patients to developing chronic pain in adulthood. Unfortunately, there is a
paucity of randomized controlled trials focusing on acute perioperative pain management in the
pediatric patient with chronic pain, resulting in treatment options that are rarely evidence-based.
References:
1. Alfonso et al. Rev Bras Anestesiol 2012; 62:118-133
2. Belgrade et al. Pain Medicine 2010; 11:1819-1826
3. Berta E et al. Paediatr Anaesth 2008;18:593-7
4. Bhalla et al.J Anesth. 2012; Sep 25
5. Bosenberg A. Pediatric Anesthesia 1155-5645
6. Brown RH, Tewes PA. Anesthesiology 1989;70:1011-2
7. Dahlgren N, Tornebrandt K. Acta Anaesthesiol Scand 1995; 39: 872-80
8. Faccenda KA, Finucane BT. Drug Saf 2001; 24: 413-22
9. Gerlach et al. The annals of pharmacotherapy 2007 Vol 41
10. Giaufre E, Dalens B, Gombert A, et al. Anesth Analg 1996; 83: 904-12
11. Gilbert J, Hultman J. Acta Anaesth Scand 1989;33:142-5
12. Howard, R. JAMA 2003; Vol 290; 18
13. Ivani, G et al. Pediatr Anesth 2007;520-33
14. Lonnqvist, PA. Anaesthesia. 1992;47:607-9
15. Mason et al. Anesthesia-Analgesia.org Nov 2011 113: 5
16. McMorrow et al. Pediatric Emergency Care Mar 2012 28:3
17. Phan et al. Pediatric Drugs 2008; 10 (1): 46-69
Funding: none
A224
ISOLATED LUMBAR RADICULAR SYMPTOMS IN THE CONTEXT OF SEVERE MULTILEVEL
LUMBAR SPINAL STENOSIS: A CASE OF CONTRASTING NATURAL HISTORY OF DISC
EXTRUSION AND SPINAL STENOSIS
K. Namiranian, M. Rahbar
1
2
Anesthesiology, Baylor College of Medicine, Anesthesiology, Veterans Affairs Medical Center,
Houston, TX, USA
A 65 years old Hispanic male was referred to our pain service for the treatment of his recent onset
right flank pain. The onset of pain was sudden, without any inciting event, located over his right flank
with radiation to his lower abdominal and inguinal areas. The patient has had a history of chronic low
back pain with bilateral knee pain for several years. His chronic pain in the lower extremities is highly
suggestive of neurogenic claudication; He uses a walker to lean forward when he walks and his pain
alleviated very soon after sitting down. The examination of the knees was unremarkable. The work-up
for urinary stone disease done by patient´s primary care provider was negative. An MRI of lumbar
spine showed post- laminectomy changes at L4 and L5 levels, multilevel spinal canal stenosis most
severe at L2-3 causing cauda equina compression, intervertebral disc extrusion with caudal migration
at T12-L1 and disc extrusion with rostral migration at T11-12. The flank pain was very intense and
unresponsive to oral pain medications. This pain however, spontaneously subsided, two months after
its onset. By the time the patient was seen in the pain clinic, he had no complaint of right flank pain.
We related the flank pain to his disc extrusion at T11-12 causing nerve root impingement and not at
T12-L1 which was more central and not causing any nerve root impingement. As expected, a followup lumbar spine MRI showed that the T11-12 disc extrusion completely resolved spontaneously.
However, the disc extrusion at T12-L1 and severe spinal stenosis causing cauda equina compression
at L2-3 seem to have remained unchanged. The patient chose to have no treatment for his spinal
stenosis and was quite satisfied with the outcome.
Conclusion: The presentation of radicular pain can lead clinicians in the identification of the location
of nerve root injury, even in structurally complicated post-surgical multilevel spinal pathology. Careful
review of actual MR images is essential, in order to make clinical-radiographic correlation. In
formulating a treatment plan, the natural history of the disease causing the main complaint must be
considered. Large migrated disc extrusions are more likely to resolve spontaneously and surgical
treatment is often not necessary.
A225
SAFE USE OF HIGH-DOSE TANDEM PARAVERTEBRAL CATHETERS FOR MULTIPLE RIB
FRACTURES IN AN ELDERLY PATIENT
B.R. O'Donnell, S. Khezri, I. Bentov, S. Chiu, A. Stogicza, W.T. Edwards, M. Depinto
Anesthesiology and Pain Medicine, Harborview Medical Center/Univ of Washington, Seattle, WA,
USA
Introduction: We report use of two paravertebral catheters placed in an elderly patient with multiple
one-sided rib fractures (4-10) and their successful use for 4 days employing a high rate infusion
without local anesthetic toxicity.
Case report: A 96 year-old male had fallen off a ladder injuring his left side: fracture of ribs 4-10,
small apical pneumothorax, pulmonary contusion, T12 anterior compression fracture, L1-L5
transverse process fractures, lumbar hernia, and retroperitoneal hematoma.
He was not responding well to hydromorphone PCA + oral acetaminophen, and the Pain Relief
Service was called to assess suitability of epidural catheter placement. It was expected that the
hypotension, induced by blockade of the sympathetic nerve fibers to the heart or by covering the 7+
spinal segments affected, would likely prohibit a sufficient concentration of local anesthetic for
optimum benefit. It was proposed that two paravertebral catheters be placed in lieu of the epidural
catheter.
After obtaining informed consent, the patient was placed in the right lateral decubitus position. Using a
modified Greenglass technique (1), a 17 gauge Touhy needle was advanced ~1 cm beyond the T6
transverse process and 3 cm of catheter was advanced beyond the needle tip. With the position
unchanged, using the same technique, a second catheter was placed at the T9 level. After a negative
test dose of 3 mL of 1.5% lidocaine containing 15 mcg of epinephrine, a loading bolus of 5 mL of
0.5% ropivacaine was injected into each catheter. Infusions of 0.2% ropivacaine at 6 mL/hr were
initiated in each paravertebral catheter.
The next day revealed good pain relief (0-3/10) but difficulties with deep inspiration and coughing.
Both infusions were increased to 8 mL/hr. Assessment another day later revealed improved pain relief
(0-2/10) but continued difficulties with deep inspiration and coughing. The patient denied signs of local
anesthetic toxicity (ringing in the ears, metallic taste in the mouth), so both infusions were increased
to 10 mL/hour.
Concern was exhibited as the total rate of infusion was substantially higher than maximally utilized
(0.2% ropivacaine at 12 mL/hr, Lönnqvist PA, personal communication). Nonetheless, the patient was
maintained on the high rate infusions for another two days with no symptoms of local anesthetic
toxicity. ECG showed no dysrhythmia or signs of altered conduction. The catheters remained in place
for four days with continued relief. At conclusion of the infusion, ropivacaine levels were 2.8 mcg/mL,
above the maximum tolerated levels of 2.2 mcg/mL noted by Knudsen et al. (2), but comparable to
bupivacaine levels reported by Dauphin et al. (3) After catheter removal, the patient's pain was
sufficiently controlled with a combination of oxycodone and acetaminophen.
Discussion: This case demonstrates that tandem paravertebral catheters can be placed to achieve
regional anesthesia in circumstances unavailable for treatment via epidural catheter. The lack of
hemodynamic difficulties or local anesthetic toxicity reveals the safety of this method used to manage
multiple rib fractures.
References:
1. Anes. Clin. N. Amer. 2000 Jun;18(2):347-353.
2. Br. J. Anaesth. 1997 78: 507-514.
3. Can. J. Anes. 1997 44(4): 367-370.
A226
SUCCESSFUL PERIOPERATIVE ANALGESIA OF ANTERIOR ILIAC CREST BONE HARVEST
USING A CONTINUOUS TRANSVERSALIS ABDOMINIS PLANE BLOCK
T. Ozelsel, B. Tsui, J. Green
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Each year, more than 500,000 bone graft procedures are performed in the United
1
States, and approximately 2.2 million are performed worldwide, with significant cost. Post-operative
pain is considered the most common complication of iliac crest bone harvest; other significant
2
complications include nerve injury, hemorrhage, fracture, hernia, and ureteral injury. Chronic pain is
estimated to develop in between 20% and 39% of all patients. Acute pain can lead to difficult post3
operative patient management and prolonged hospitalization.
Materials and methods: We describe the use of the new Pajunk MultiSet 211156-40E catheter-over4
needle unit in the postoperative management of postoperative pain in a patient receiving an anterior
iliac crest bone graft harvest.
Results: The catheter was run in intermittent bolus technique for 48 hours post-operatively with good
clinical success.
Discussion: Different methods of regional anesthesia have been described in the management of
5,6,7
post-operative pain in patients for bone graft harvest with varying degrees of success.
In our
experience pain continues past the duration of single-shot nerve blockade and needs to be controlled
continuously. Further the varying surgical techniques employed in harvesting bone graft affecting
8
9
different nerves in the still not fully understood innervation of the iliac crest make a differentiated
approach in analgesia necessary and will offer ground for further clinical investigation.
References:
1. Giannoudis PV, Dinopoulos H, Tsiridis E: Bone substitutes: an update. Injury 2005; 36 Suppl 3:
S20-S27
2. Boone DW: Complications of iliac crest graft and bone grafting alternatives in foot and ankle
surgery. Foot Ankle Clin. 2003; 8: 1-14
3. Jäger M, Westhoff A, Wild R: Knochenspanentnahme am Becken. Techniken und Probleme.
Orthopäde 2005; 34: 994
4. Ip V, Bouliane M, Tsui B: Potential contamination of the surgical site caused by leakage from an
interscalene catheter with the patient in a seated position: a case report. Can.J.Anesth. 2012;
10.1007/s12630-012-9798-1
5. Hebbard PD: Transversalis fascia plane block, a novel ultrasound-guided abdominal wall nerve
block. Can J Anaesth 2009; 56: 618-20
6. Chin KJ, Chan V, Hebbard P, Tan JS, Harris M, Factor D: Ultrasound-guided transversalis fascia
plane block provides analgesia for anterior iliac crest bone graft harvesting. Can J Anesth (2012)
59:122-123
7. Chiono J, Bernard N, Bringuier S, Biboulet P, Choquet O, Morau D, Capdevila X: The UltrasoundGuided Transversus Abdominis Plane Block for Anterior Iliac Crest Bone Graft Postoperative Pain
Relief. Reg Anesth Pain Med 2010;35: 520-524
8. Zouhary K: Bone Graft Harvesting From Distant Sites: Concepts and Techniques. Oral Maxillofacial
Surg Clin N Am 22 (2010) 301-316
9. Gray´s Anatomy (40th English Edition) Editor; Susan Standring Chapter 79, Pg. 1356; "Pelvic
Girdle, Gluteal Region and Thigh: Hip Bone; Ilium"
Churchill Livingstone, Elsevier, 2008
Funding: no external funding
Conflict of interest: The continuous nerve block set (Pajunk MultiSet 211156-40E) was a modified
and re-designed continuous nerve set by Dr. Ban Tsui
A227
THE USE OF ULTRASOUND GUIDANCE FOR SAPHENOUS NERVE ALCOHOL NEUROLYIS - A
CASE STUDY
V. Patel, P. Kim, M. Ko, S. Shaikh
Department of Anesthesiology, St. Luke's-Roosevelt Hospital Center, New York City, NY, USA
Introduction: The Saphenous nerve gives rise to branches that innervate not only cutaneous areas
of the anterior and medial knee, but also the anterior inferior capsule of the knee joint itself(1). Recent
publications show the feasibility of performing ultrasound guided saphenous nerve block that spares
motor blockade for pain control in surgical procedures involving the knee(2). In this case study, we
investigate the use ultrasound guidance to perform an alcohol neurolysis of the saphenous nerve in a
woman with chronic right knee pain.
Case: A 79 y/o Female with a history of CAD, hypertension, osteoarthritis and chronic back pain
presented to Pain Management clinic for treatment of chronic dull achy right knee pain (VAS 6-8/10)
that worsens with activity, interfering with her daily activities and ambulation. A trial of saphenous
nerve block had provided her with decreased pain prior to the procedure. After obtaining informed
consent, the patient was given light sedation with midazolam. The area in the midthigh was prepped
and draped in the usual fashion. A high frequency ultrasound transducer was used to visualize the
saphenous nerve in the adductor canal.
[Ultrasound probe position]
A 22G 2 inch needle was guided to an intraneural position. After negative aspiration of blood, a total
of 20mL of solution (12mL of 40% alcohol and 8mL of 0.25% Bupivicaine) was injected.
[Ultrasound Image of Saphenous Nerve]
The patient was monitored for 4 hours post procedure and only complained of mild discomfort in the
injection area.
Results: Initial results (1 week and 1 month follow up) have been promising. Despite loss of
sensation on the medial leg from knee extending to mid foot, the patient has had a greater than 60%
reduction in her pain scores (VAS 2-3) with improved ambulation and quality of life. Furthermore,
there has been no evidence of any motor function compromise.
References:
1) Benzon H et al. Anesthesiology. 2005; 102:633-8
2) Saranteas T et al. RAPM. 2011 Jul-Aug;36(4):399-402
A228
POST-OPERATIVE EPIDURAL PAIN MANAGEMENT IN PATIENT WITH MULTIPLE SCLEROSIS
AND BACLOFEN PUMP
K. Patel, D. Elmofty
University of Chicago, Chicago, IL, USA
Multiple Sclerosis (MS) occurs in genetically susceptible patients following various triggering events
leading to an autoimmune reaction resulting in demyelination and glial scaring of the brain and spinal
cord. This, in turn, causes a conduction blockade on sodium channels of neural pathways resembling
a neural blockade caused by local anesthetics. Patients often have various neurological deficits
including: sensory, motor, cranial nerve, spasticity, etc. Regional and neuro-axial anesthetic
techniques in patients with progressive neurological diseases are often not preferred because of the
difficulty in assessing new or progressive neurological deficits perioperatively. We present a case with
a patient with MS with previous intrathecal baclofen pump, in which a thoracic epidural was placed for
perioperative pain management.
The patient is a 46 year old ASA 3 female with past medical history significant for MS with baseline1/5
lower extremity weakness and loss of sensation. Patient is wheel chair bound. She had functional use
of her bilateral upper extremities with occasional weakness and loss of sensation. She suffered from
severe upper and lower extremity spasms and had an intrathecal baclofen pump implanted. She
presented for cystectomy and ileal conduit secondary to her history of neurogenic bladder with
vesiculvaginal fistula. Epidural analgesia was discussed with the patient preoperatively secondary to
concerns of postoperative respiratory dysfunction from narcotics and patients underlying intercostals
muscle weakness. There was extensive discussion with the patient regarding risk/benefits for epidural
analgesia with emphasis on the possibility for worsening neurological deficits and difficulty in
assessing these deficits perioperatively Because of her pre-existing severe neurological deficits, the
patient consented for a thoracic epidural in an attempt to avoid worsening of her respiratory functional
status postoperative. Preoperative thoraco-lumbar spine radiography showed the baclofen pump
catheter entered at L2-L3 interspace, and terminated at T11-T12 with severe scoliosis. An epidural
was placed at T8-T9 without fluoroscopic guidance avoiding entry level at L2-L3. The patient was
started on a bupivicaine 0.1% and hydromorphone 20mcq/mL solution infusing at 3mL/hr with a 2mL
every 20 min PCEA. Patient had a bilateral T6-L1 sensory level. Patient tolerated the epidural well,
with excellent pain control and no new neurological deficits or complications. The epidural was
removed on post-operative day 4.
Patients with multiple sclerosis present with unique challenges when it comes to perioperative pain
management. It is important to develop an analgesic plan that will preserve respiratory function.
Epidural analgesia offers many benefits but in a patient with baseline neurological deficits, placement
can be controversial. In our patient, the benefits outweighed the risk of difficulty in evaluating for new
or progressive neurological deficits. Placement of the epidural was also challenging secondary to
patient's severe scoliosis and intrathecal catheter. This patient required a preoperative radiography to
evaluate the position of the intrathecal catheter. Patient education and extensive risk/benefit
discussion is extremely important in these situations. Furthermore, detailed documentation of a
preoperative and a daily neurological exam needs to be conducted.
A229
LOWER LOBE LUNG INFILTRATE: INFECTION, ASPIRATION OR JUST VOLUME LOSS
K. Patel, T. Malik
University of Chicago, Chicago, IL, USA
Continuous interscalene block is an effective and safe technique for inpatient and outpatient pain
control. Large scale observational studies of ambulatory catheter programs reveal most patients were
successfully managed with daily phone calls required limited interventions on the part of managing
1
anesthesiologists. However; it is not a completely benign intervention. Infection, hematoma,
dislodgement and entrapment are the most common complications. Phrenic nerve palsy is a common
2
complication after an interscalene block. We report a case where an interscalene ambulatory
catheter placed for postoperative pain control for shoulder surgery caused ipsilateral diaphragmatic
dysfunction and radiological findings on CXR resulting in unnecessary diagnostic and therapeutic
interventions.
Case report: A 52 year old, ASA 2 patient, was scheduled for right arthroscopic rotator cuff repair
surgery. An interscalene catheter was placed using ultrasound an hour before surgery. The Catheter
was activated with 30 ml 0.5% bupivacaine. The patient developed loss of sensation and motor block
in C5, C6, C7 distribution within 30 min. Patient remained stable and complained of no shortness of
breath. The surgery was done in sitting position. She received a propofol infusion (100
mcg/kg/minutes) for sedation. No airway support was needed, and the patient breathed
spontaneously throughout the case with 4L nasal cannula. Post-operatively, the patient was very
comfortable and was sent home with a disposable local anesthetic pump. She received 0.125%
bupivacine at 6 mL/hr with 5mL bolus/hr as needed. At 9 pm that evening, she felt midthoracic
posterior chest wall discomfort at interscapular level. She gave herself 5 ml bolus dose. Within 10
minutes she started feeling “choking” sensation. She spoke with the on call pain team resident who
advised her to stop the infusion and go to the nearest emergency department. In the ED, her
symptoms self-resolved, however based on her symptoms she received a cardiac and pulmonary
embolism workup. Her cardiac enzymes and V/Q scan were negative. CT scan revealed bilateral
lower lobe atelectasis, worse on right side. She was diagnosed with pneumonia despite normal CBC
and CRP. She was empirically started on IV antibiotics. IV heparin started in ER was discontinued.
The Interscalene catheter was removed and intravenous hydromorphone started for surgical pain
control. She was admitted with the working diagnosis of right lower lobe pneumonia, possibly
aspiration. Her symptoms quickly resolved. The managing physician was informed by the pain service
that her right lower lobe volume loss most likely due to phrenic nerve palsy from interscalene catheter
and recommended the patient be discharged since preliminary work-up was negative.
Discussion: Continuous interscalene block has been shown to be an effective modality for
postoperative pain control. However, as with any procedure, risks are always present. We suspect
that unilateral phrenic nerve palsy caused unilateral diaphragmatic paresis, which resulted in a right
lower lobe atelectasis and the patient's symptoms. This case report illustrates that importance of good
communication and education between the services involved as well as with the patient. Effective
communication and regular follow-up in the peri-operative period will prevent such complications from
occurring.
A230
PARASPINOUS AND CHEST WALL ABSCESSES FOLLOWING THE PLACEMENT OF A
CONTINUOUS THORACIC PARAVERTEBRAL BLOCK AND A CHEST TUBE
C. Lin, B.A. Pearce-Smith, J.E. Chelly
Division of Acute Interventional Perioperative Pain, UPMC - Presbyterian Shadyside Hospital,
Pittsburgh, PA, USA
Introduction: Continuous paravertebral block is an effective method for managing acute chest pain
for trauma patients who have suffered rib fractures. We report a case of a patient, without a previous
history of immunosuppression, who developed paraspinous and chest wall abscesses. This case
report highlights the differential etiology of abscesses following invasive procedures in trauma
patients.
Case report: A 48 year old previously healthy male suffered a 10 foot fall from ceiling scaffolding and
nd
th
presented to the emergency department with a right clavicle fracture, right 2 - 6 rib fractures, right
small pneumothorax and a possible diaphragmatic injury. There was no antecedent history of MRSA.
th
The patient urgently received a right chest tube in the emergency department along the 4 interspace.
On post-trauma day (PTD) #1, operative video-assisted thoracic surgery demonstrated a small
hemothorax, with no diaphragmatic injury. On PTD #2, the patient received a single continuous
thoracic paravertebral nerve block for acute pain management. The nerve block was placed at the
right T6 level under strict aseptic technique, including sterile Chloraprep© skin preparation, facemask,
gloves, the use of a prepackaged B Braun custom catheter kit and a large drape. The paravertebral
nerve block catheter remained in situ for a total of 3 days,during which time he received no antibiotic
therapy. On the following day, the paravertebral nerve block catheter was removed (PTD #6), the
patient developed a leukocytosis 13.5, fever 39.2 °C and noted tenderness and purulent drainage
from the single right PVB insertion site. Intravenous Unasyn was begun and bedside surgical
debridement was performed - Cultures of the PVB abscess site grew MRSA. CT Chest and CT
Thoracic Spine demonstrated a 4x1cm superficial fluid collection in the Right Paraspinous Muscle,
without extension into Paravertebral Space and without Thoracic Spine invasion. Concurrently, his
chest tube site also developed a purulent abscess, also requiring I&D, again yielding positive cultures
for MRSA. Subsequently, the patient underwent a full operative surgical irrigation and debridement of
the PVB site. He was switched to intravenous vancomycin for coverage of MRSA. The patient
recovered, and was discharged PTD #12 on oral Bactrim without further complications
Figure 1
[Right PVB Abscess]
Discussion: Trauma patients with rib fractures are appropriate candidates for continuous thoracic
. 1,2
paravertebral nerve blocks to manage chest wall pain and improve respiratory function
Although,
the cited risks of thoracic paravertebral nerve blocks include pneumothorax, pleural puncture,
bleeding, epidural or intrathecal spread, infection, hypotension and spinal headache, these
complications are rare. However, the fact that this patient developed concurrent chest wall and
superficial paraspinous abscesses, with the same organsim, suggests that the etiology of such
infectious complications may be more complex.
Bibliography:
1/Adelman MH, I. C. (1946). Acute aseptic meningitis following paravertebral lumbar sympathetic
blocks. Anesthesiology, 7:422-5.
2/Chelly, J. (2012). Paravertebral blocks. Anesthesiol Clin., 30(1):75-90.
3/Karmakar MK, C. L. (2003). Continuous thoracic paravertebral infusion of bupivacaine for pain
management in patients with multiple fractured ribs. Chest, 123(2):424-31.
A231
TREATMENT OF FIFTH DIGIT ISCHEMIA WITH BRACHIAL PLEXUS BLOCKADE, VIA A
SUPRACLAVICULAR APPROACH, AFTER FAILED STELLATE GANGLION BLOCK
J. Pierson, M. Anitescu
Anesthesiology and Critical Care, The University of Chicago, Chicago, IL, USA
A 33-year-old gentleman with a history of left ulnar artery thrombosis secondary to
hyperhomocysteinemia was referred to the University of Chicago Pain Management center for a
stellate ganglion block. Pt was initially managed ulnar artery thrombectomy, however, suffered
continued fifth digit ischemia from emboli. Pt had been unsuccessfully medically managed with
heparin, lovenox, Coumadin, aspirin and nifedipine. Under fluoroscopic guidance, a spinal needle was
advanced with sterile technique to the junction of the C7 vertebral body and the transverse process,
with appropriate spread of Omnipaque 180 after negative aspiration. Once appropriate placement
was confirmed, 5 mL 0.25% bupivacaine and 5 mL 1% lidocaine with 40 mg Kenalog was injected.
The patient experienced no relief in his pain, and no circulatory or temperature changes were noted.
After failed stellate ganglion block, the brachial plexus was identified under ultrasound in the
supraclavicular region. Under sterile technique, a 22-gauge 2-inch nerve stimulator needle was
advanced, and appropriate twitches were obtained at less than 0.4 mA. No heme was aspirated, no
paresthesias were eliecited. Then, a total of 30 mL solution consisting of 40 mg Kenalog and 0.25%
bupivacaine was injected in 5 mL increments. Appropriate hydrodissection was noted under
ultrasound. The patient tolerated the procedure well. Upon completion of the procedure, patient noted
resolution of his left 5th digit pain. Upon follow up visit with his orthopedic surgeon, the patient
reported complete resolution of his symptoms. His physical exam was consistent with intact peripheral
circulation of his 5th digit by color, temperature, pulsation and lack of pain. The patient was placed on
long term anti-coagulation medications for management of his hyperhomocysteinemia.
Stellate ganglion blockade is a well described intervention for improvement of upper extremity
circulation. In our case, we describe an alternative approach for upper extremity symathectomy aimed
at improving peripheral circulation. Because the brachial plexus contains the sympathetic fibers of the
upper extremity, brachial plexus blockade should result in upper extremity sympathectomy and thus
improve distal collateral circulation in the setting of thrombosis, emboli or spasm. The supraclavicular
approach was chosen because the entire sensory, motor and sympathetic innervations of the upper
extremity is carried in just three nerve structures confined to a small surface area, creating a highly
predictable and dense block. In the setting of failed stellate ganglion block, the supraclavicular
approach to the brachial plexus can provide satisfactory upper extremity sympathectomy and
improved circulation in the setting of distal artery thrombosis, emobli or spasm.
A232
TARGETED TWO-LEVEL THORACIC EPIDURAL BLOOD PATCHES FOR SPONTANEOUS
INTRACRANIAL HYPOTENSION DUE TO LEAKING MENINGEAL CYSTS
J.J. Rivera-Melendez, F. Elahi, T.L. Dann, R. Sripada
Department of Anesthesiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
Introduction: Spontaneous intracranial hypotension is a rare disease that occurs in 5 out of 100,000
people.(1) Besides conservative management with bed rest, caffeine, hydration and, abdominal
binder, the mainstay of treatment for SIH is the epidural blood patch. (2, 3) A multilevel CSF leak may
be suspected after performing an EBP 1-2 times with no symptom improvement.(1) We present a
case of SIH caused by leaking meningeal cysts effectively treated by a targeted two-level EBP.
Case report: A 64 yo male with a history of bifrontal headaches self-treated with acetaminophen over
the last two years presented to our institution. He describes his headaches were getting progressively
worse, related to position, and difficult to manage after he underwent rotator cuff surgery one month
prior. He sought medical attention at an outside hospital, including a lumbar puncture and then an
epidural blood patch without success.
The patient was started on conservative management and the acute pain service was immediately
consulted. At the time, it was suggested that a repeat epidural blood patch would not be beneficial
given the failure of the first one. A spine MRI showed intracranial hypotension and suggested a
possible CSF leak at the AO joint and demonstrated meningeal cysts in the thoracic spine.
Subsequently, it was advised to pursue a study to determine the presence and location of a CSF leak.
A CT myelogram demonstrated contrast extravasation through cysts at C7-T1 and T6.
He was consented for fluoroscopically-guided epidural blood patches. An 18-Ga Touhy was advanced
into the C7-T1 interspace and the epidural space and confirmed with fluoroscopy, then repeated at
the T6-T7 level. A total of 12 ml of the patient´s blood was injected at C7-T1 and 15 mL at T6-T7. The
patient did not experience any complications and noted slight improvement immediately. He was
discharged headache-free three days later.
Discussion: This case reveals an unusual occurence in which a headache evolved over time to
become a positional headache. The first attempt at a blood patch in an outside hospital failed as it did
not target the unknown leaking levels by assuming it was caused by a previous LP. Myelography with
iodinated contrast followed by thin cut CT of the entire spine has been shown to define accurately the
location and extent of a CSF leak.(4) CSF-leaking meningeal cysts were discovered at the thoracic
level allowing effective treatment with a targeted two-level fluoroscopically-guided epidural blood
patch.
References:
1) Kim SY, Hong JH. Epidural Blood Patches in a Patient With Multi-level Cerebrospinal Fluid
Leakage That Was Induced by Spontaneous Intracranial Hypotension. Korean J Pain 2010; 23:46-50.
2) Schievink WI. Spontaneous spinal cerebrospinal fluid leaks. Cephalalgia 2008; 28:1345-56.
3) Sencakova D, Mokri B, McClelland RL. The efficacy of epidural blood patch in spontaneous CSF
leaks. Neurology 2001; 57:1921-3.
4) Schievink WI, Meyer FB, Atkinson JLD, Mokri B. Spontaneous spinal cerebrospinal fluid leaks and
intracranial hypotension. J Neurosurg 1996; 84:598-605.
Funding: None
A233
A CONTINUOUS PERIPHERAL NERVE BLOCK FOLLOWING A TRAUMATIC BELOW KNEE
AMPUTATION IN A 10 YEAR OLD CHILD
R. Sachdeva, S. Millerchip, M. Ziauddin, C. Hillermann
UHCW, Coventry, Coventry, UK
Introduction: Continuous peripheral nerve catheters have been used in paediatrics for orthopaedic
1
procedures for short duration . There are very limited studies of the use of continuous infusion of low
2
dose local anaesthetic agents for long term pain management in patients following limb amputation .
Kotiniemi et. al. emphasized the fact that inadequate pain relief in children was one of the predicting
factors of problematic behavioural changes in the near postoperative period. These changes could
3
persist for three to four weeks after surgery . We present a case of a traumatic below knee
amputation (BKA) after dog bite managed with continuous sciatic nerve block for 10 days.
Case study: A 10 year old girl (42kg) was admitted to the hospital following a dog bite.
Reconstructive surgery failed and the patient underwent a BKA
The patient was anaesthetised using rapid sequence induction with thiopentone and suxamethonium
and maintained with sevoflurane 3.0% in O2/Air, atracurim, morphine (6mg) and paracetamol.
At the end of the procedure a continuous sciatic nerve catheter was placed with ultrasound in the
popliteal fossa at the bifurcation of the sciatic nerve and a 15 ml bolus of 0.25% L-Bupivacaine was
given through the catheter followed by infusion of 0.125% L-Bupivacaine at fixed rate of 5ml/hr. A
single shot mid-thigh saphenous nerve block (ultrasound guided) was also performed with 7ml of
0.25% L-Bupivacaine.
Postoperatively the patient was comfortable and required no breakthrough analgesia in PACU and
was transferred to the paediatric high dependency unit. Regular post-operative analgesia prescribed
was paracetamol, codeine phosphate, ibuprofen and gabapentin.
Unfortunately in the following morning catheter was dislodged. After 3 hours the patient started getting
severe phantom limb pain which was difficult to control with additional opioid therapy. She was
brought back to theatre for reinsertion of the catheter under general anaesthesia. L-bupivacaine (15ml
of 0.25%) with clonidine 80 micrograms was injected around the nerve and the continuous infusion of
0.125%L-bupivacaine was restarted.
The patient was reviewed daily by the acute pain team and the catheter was removed on day 10. She
was discharged the following day with regular paracetamol, ibuprofen and gabapentin and did not
require any supplementary opioids. She could mobilize in a wheel chair and didn´t complain of any
phantom limb pain. She is undergoing rehabilitation and physiotherapy in the community.
Conclusion: Use of continuous peripheral nerve catheters in our patient provided excellent pain relief
and avoided the development of phantom limb pain without the risks associated with opioids.
References:
1. Dadure C, Pirat P, Raux O, et al. Perioperative continuous peripheral nerve blocks with disposable
infusion pumps in children: a prospective descriptive study. Anesth Analg 2003; 97: 687-90.
2. Ivani G, Codipietro L, Gagliardi F, Rosso F, Mossetti V, Vitale P. Along-term continuous infusion via
a sciatic catheter in a 3-year-old boy. Paediatr Anaesth 2003; 13: 718-21.
3. Kotiniemi LHRyhänen PTMoilanen IK Behavioural changes in children following day-case surgery:
a 4-week follow-up of 551 children. Anaesthesia.1997;52:970-976.
A234
IDENTIFICATION OF THE LOCATION OF PERIPHERAL NERVE CATHETERS DURING
PERIPHERAL NERVE BLOCKS USING PUMPING TECHNIQUE
L. Arora, V. Salmasi, H. Elsharkawy
Anesthesiology, Cleveland Clinic Foundation, Cleveland, OH, USA
Introduction: Optimum positioning of Peripheral Nerve catheter is vital for successful nerve block.
There is incidence of secondary catheter failure in spite of good nerve localization on ultrasound, due
to improper positioning around the nerve. One of the main reasons is difficulty to localize the tip of
Peripheral nerve catheters in the desired field. We described a novel technique called Pumping
maneuver that can really be helpful to achieve this goal.
Discussion: One of the main reasons of malposition is difficult to identify the tip of these small
peripheral nerve catheters around the nerve. So we used our novel technique called Pumping
maneuver in a series of four patients who got ultrasound guided femoral, anterior sciatic, Popliteal
and interscalene peripheral nerve catheters for postoperative pain relief to identify the location of the
tip of the peripheral nerve catheter using color Doppler.
After introduction of the catheter 5 cm beyond the needle tip in the desired field of block, the guide
wire was re-introduced in the catheter and was moved back and forth. This movement produced color
Doppler effect in the area around the nerve on using ultrasound color Doppler that helped us to
identify the tip of peripheral nerve catheter.
Postoperatively pain was well controlled in all these patients using continuous infusions with minimum
requirement for opioids reflecting successful blocks.
Pumping Maneuver Pumping the stylet in and out of a stationary needle shaft increases the
echogenicity of the needle shaft and tip, thereby facilitating needle localization. We applied it to the
catheters.
The increased echogenicity has been attributed to the formation of micro bubbles inside and outside
the catheter. It can be achieved using the color Doppler
[Supraclavicular nerve block]
[Sciatic nerve identification]
Conclusion: Confirmation of catheter around the nerve can be difficult to visualize even with USG.
Pumping maneuver along with color Doppler can help the user to identify the catheter and achieve
successful block.
This technique has not been studied before. It is based on our clinical experience, which requires
future studies to establish its validity and reproducibility.
A235
FEMORAL VEIN THROMBOSIS DISCOVERED DURING US GUIDED REGIONAL ANESTHESIA
PROCEDURE
B.U. Schmitz, K. Yates
Anesthesiology, Texas Tech University HSC, Lubbock, TX, USA
Case report: A 45-year-old female was scheduled for a post-operative ultrasound-guided fascia iliaca
compartment block in the PACU after re-implantation of a total hip arthroplasty.
The patient had an extensive medical history including a previous THA and consecutive hardware
removal due to an infection, liver cirrhosis, peptic ulcer disease, upper GI bleeding, chronic
pancreatitis, HTN and chronic lower back pain.
During the ultrasound evaluation a hyperechoic structure, pulsating with the arterial pulse of the
adjacent femoral artery was discovered in the femoral vein in the groin. In the longitudinal view this
structures extended over more than two inch.
The preliminary diagnosis of a deep vein thrombosis in the femoral artery was made and the primary
orthopedic team and vascular surgery informed. A formal vascular ultrasound performed by radiology
confirmed the diagnosis of a deep vein thrombosis on the left site. Though the thrombus was
considered older the possibility of dislocation of the thrombus or thrombus parts was considered
significant due to its high mobility. The patient underwent an insertion of an IVC filter the same day.
During her postoperative course the patient did not experience any problems from her DVT.
Discussion: Deep vein thrombosis is a common complication of total hip replacement surgery.
Before the routine use of thrombosis prophylaxis the incidence of deep vain thrombosis was 40-60%
and the incidence for proximal DVT 10-30% 7-14 days after major orthopedic surgery. Since the
introduction of thrombosis prophylaxis the incidence of symptomatic DVTs decreased to 1.3-10%
1
within 3 month after surgery.
Our patient had a significant elevated risk for DVT: repeated joint surgery, infection and prolonged
period of no or minimal physical activity.
A fascia iliaca compartment block provides good pain control after hip surgery and is a valuable
alternative to the lumbar plexus block. It is a relatively superficial block that can be easily and
successfully performed with ultrasound guidance, the patient remains supine and the block has a low
risk for side effects and complications. The ultrasound evaluation includes the identification of the
femoral vessels, the femoral nerve, the fascia lata and iliaca and the iliacus muscle, the needle is
inserted more laterally to the transducer (compared to the FN insertion point) and a higher LA volume
of 30-40 ml is injected within or right below the fascia iliaca.
Only 3 incidences of diagnosis of a deep vein thrombosis during US guided regional anesthesia have
2,3
been reported in Pub Med , none of the patients had previous major orthopedic surgery, however
anesthesiologists performing regional anesthesia should be aware of the potential for a proximal DVT
especially in a patient undergoing repeat major orthopedic surgery.
References:
1 Geerts WH. Prevention of Venous Thromboembolism Amrican College of Chest Physicians
Evidence-Based Clinicak Practice Guidelines. CHEST 2008; 133:381-453S
2 Sites B, Spence B, Gallagher J, Beach M. On the Edge of the Ultrasound Screen: Regional
Anesthesiologists Diagnosing Nonneural Pathology. Reg Anesth Pain Med 2006; 31:555-6
3 Sutin KM. Deep venous thrombosis revealed during ultrasound-guided femoral nerve block. Br J
Anaesth 2005;94:247-8
A236
LATERAL PECTORAL NERVE BLOCKS AFTER BREAST AUGMENTATION
M. Semenza II, G. Woodworth, J.-L. Horn
Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
Introduction: Breast augmentation surgery is a commonly performed cosmetic procedure and can be
associated with significant postoperative pain when the prosthesis is placed beneath the pectoralis
major muscle. (1-3) Although thoracic intercostal nerves provide sensory innervation to the breast, the
contribution of the pectoral nerves to post-breast augmentation pain has yet to be determined. We
present the management of severe postoperative pain after breast augmentation surgery with lateral
pectoral nerve blocks as well as the technique to block the nerves.
Methods: A 36 year old female, ASA1 underwent bilateral breast augmentation surgery under
balanced general anesthesia and experienced uncontrolled pain in the PACU with systemic
medications. In order to improve analgesia and avoid hospital admission, lateral pectoral nerve blocks
with back up paravertebral blocks were discussed with the patient. This patient had been consented
in the preoperative area for a possible postoperative block. An HD 11 XE ultrasound machine with a
L12-3 MHz probe (Philips, Bothell, WA) was used to perform the blocks. The probe was placed 2cm
caudad and parallel to the mid clavicle. The pectoral arterial branch of the thoracoacromial trunk was
identified in the fascial plane between the pectoralis major and minor muscles. After sterile prep and
using sterile technique, a 10 cm 22 gauge Sonoplex Stim needle (Pajunk, Geisingen, Germany) was
advanced under ultrasound in-plane next to the artery. Five ml of 0.5% ropivacaine was injected next
to the artery after negative aspiration on each side.
Results: Preblock pain score (VAS) was 3/10 at rest and 7/10 with deep breathing. Patient was
unable to move due to uncontrolled pain despite maximum opioid administration. Within 5 minutes of
the right side injection, the patient experienced complete pain relief at rest on that side with a VAS at
0/10. The contralateral side was then injected with the same results. During active mobilization and
deep breathing her pain score was at 3/10 with pain control rated as being excellent. The patient did
not require further analgesics and was discharged from the facility with good pain control 36 minutes
post block. On telephone follow-up her pain control was rated as excellent without any side effects.
The patient performed household tasks as usual until the block wore off about 8hrs later. She then
needed opioids for the next 12hrs but was very satisfied with her overall pain control
Conclusion: We report a case of successful blockade of the lateral pectoral nerves to improve
postoperative analgesia following breast augmentation. This case confirms that significant pain
afferents are carried by the lateral pectoral nerves after breast augmentation. Since those nerves
travel in a discrete fascial plane that can be readily visualized on ultrasound and infiltrated with local
anesthetics, it could become a valuable option for breast augmentation surgery.
References:
1. Wallace MS et al. Pain 1996;66:195-205.
2. Vadivelu et al. The Am Surgeon 2008;74:285-296.
3. Blanco R. 2011. Anaesthesia 2011;66:847-848.
[Lateral Pectoral Nerve Block]
A237
INTERMITTENT HOARSE VOICE CONCURRENT WITH CONTINUOUS INTERSCALENE
BRACHIAL PLEXUS INFUSION DUE TO DEFICIENT CAROTID SHEATH
T.J. Shakespeare, B.C.H. Tsui, Edmonton Academy of Regional Anesthesia
Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
Introduction: Hoarse voice after interscalene brachial plexus block for shoulder surgery is a common
1;2
side effect with an incidence of 0.8-31%. The anatomical basis for this is presumed blockade of the
recurrent branch of the vagus nerve, although the mechanism remains unclear. Here, we describe a
case of hoarseness following interscalene blockade, in which ultrasound was used to reveal the
underlying cause and mechanism of hoarse voice.
Material and methods: A 68-year-old woman, from whom consent was provided to describe the
case, received an interscalene catheter with general anesthesia for total shoulder replacement. The
patient had a BMI of 43.2, and physical examination revealed that the patient had a relatively short
3
neck. A catheter-over-needle assembly was inserted in-plane under ultrasound guidance between
the upper and middle trunks of the brachial plexus. Fifteen mL of surgical mixture (0.5% ropivacaine
and 0.125% bupivacaine) was injected into and remained in the interscalene space. After confirming
catheter tip position on ultrasound, a further 5 mL of the surgical mixture was injected under
ultrasound guidance. After this, the patient immediately experienced a hoarse voice and inability to
cough, although she did not report respiratory compromise. Surgery proceeded uneventfully, and the
patient experienced persistent hoarseness until the interscalene infusion was discontinued on postoperative day two.
Results: On ultrasound, we observed local anesthetic extending from the interscalene space behind
the anterior scalene muscle (ASM) and passing between the common carotid artery (CCA) and the
internal jugular vein (IJV), surrounding the ipsilateral vagus nerve (Figure).
[Figure]
Ultrasound revealed that the carotid sheath (CS) was absent laterally but appeared intact medially,
allowing passage of local anesthetic between the CCA and IJV. Absence of direct CS puncture was
confirmed with real-time video recording, as was a small ASM, which may have created a reduced
barrier between the interscalene groove and carotid vasculature, including the vagus nerve.
Discussion: Our observations illustrate direct vagus nerve block due to local anesthetic spread
secondary to interscalene block. In this case, ultrasound scanning helped to explain one of the
common side effects of interscalene brachial plexus block and provided valuable, real-time
information on the underlying mechanism. We encourage all regional anesthesiologists with access to
ultrasound to use it for anatomical examination in cases where side effects and complications are
present.
Reference list:
1. Borgeat A, et al. Anesthesiology 2003; 99: 436-42
2. Liu SS, et al. Anesth. Analg. 2010; 111: 617-23
3. Ip V et al. Can. J. Anesth. 2012; 59: 1125-9
Funding disclosure: Dr. Tsui is supported by the Alberta Heritage Foundation for Medical Research
and the Canadian Anesthesiologists' Society.
Personal conflicts of interest disclosure: The Pajunk MultiSet 211156-40E is modified and redesigned by Ban Tsui. Dr. Tsui also has a patent licensing agreement with Pajunk.
Figure: Local anesthetic spread from the interscalene groove (ISG; arrowheads) to the vagus nerve
(V). Location of local anesthetic is indicated by asterisks. MS, middle scalene muscle; AS, anterior
scalene muscle; IJ, internal jugular; C, carotid artery.
A238
IMPORTANCE OF VIGILANT MONITORING AFTER CONTINUOUS NERVE BLOCK - LESSONS
FROM A CASE
T. Shuster
Pain Management -Acute Pain, Cleveland Clinic, Cleveland, OH, USA
Regional anesthesia is a common mode of postoperative pain management in the orthopedic setting.
Preoperative nerve block had been proven to provide excellent analgesia through interrupting the
sensation from a certain area or the surgical limb. Uncontrolled or escalating pain, despite the
presence of a successful block, can be an indication for surgical complications and should not be
overlooked. Tissue ischemia due to vascular injuries or compartmental syndrome should be
suspected early should pain is not controlled in presence of regional anesthesia block. We describes
a case of iatrogenic injury to the axillary artery during shoulder surgery in a patient who had
continuous supraclavicular block, and, how vigilant monitoring helped in the diagnosis and timely
management of ischemia in the upper extremity.
The patient in this case report had a difficult dissection during the shoulder repair and an accidental
injury to the axillary artery, which was not identified intraoperatively. The surgery lasted for 260
minutes and was associated with 300ml blood loss. Intraoperatively, the patient had stable
hemodynamics and the surgeon reported a difficult, yet uncomplicated procedure. Post operatively,
the supraclavicular catheter was connected to an infusion pump containing 0.2% Ropivacaine. The
infusion was set up as PCA (patient controlled analgesia) to a basal rate of 8ml per hour and patient
demand dose of 12ml every 60 min as needed. The patient's pain was originally well-controlled for the
first few post-operative hours. Overnight, the pain starts to escalate in non-surgical sites; forearm and
hand, which were partly masked by the regional nerve block. On physical examination the arm was
slightly dusky, capillary refill was brisk, radial and brachial pulses were palpable and the hand was
warm. The patient was given a top up dose through the supraclavicular catheter with 15cc of 0.5%
Ropivacaine and she reported satisfactory relief of pain. Neurovascular checks were done hourly by
nursing staff at this point to rule out any progressive ischemic injury. The next morning, examination at
0900 hrs showed that the hand was cyanosed, pulses were weak and patient had increasing pain in
the hand and forearm. Nursing notified primary service, acute pain service, Vascular surgery service
was consulted immediately, emergency angiography of the right upper limb was done and it showed a
3cm segment of occlusion of the axillary artery adjacent to the shoulder joint, with reconstitution at the
level of the most distal part of the circumflex humeral artery. Immediate exploration of the patient's
right axillary artery confirmed a partial occlusion. This was repaired by a subclavian artery to brachial
artery bypass using sapheous venous graft. Pulses in the right upper limb returned. Post operatively,
the patient recovered well and gained full function of the right upper limb. The patient was discharged
home on the fourth postoperative day with full neurological and functional recovery. Currently, there
are no recommendations regarding monitoring after nerve blocks. This case report aims to improve
awareness about the need for vigilant monitoring, especially of the distal pulses after peripheral nerve
blocks.
Personal conflicts of interest disclosure: Nothing to disclose.
A239
BILATERAL CONTINOUS PARAVERTEBRAL BLOCK WITH LOW DOSE KETAMINE FOR
POSTOP PAIN MANAGEMENT FOLLOWING WHIPPLE´S PROCEDURE IN AN OPIOID
TOLERANT PATIENT WITH SPINAL CORD STIMULATOR
Y. Siddapura Ranganath, T. Brennan, R. Sripada, J. Rivera-Melendez
Anesthesiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
Case report: A 60 year old male with cancer of the head of pancreas presented for Whipple's
procedure. The patient had a spinal cord stimulator placed one year before for Intractable back pain
(with multiple back surgeries) and bilateral lower extremity pain. The laminotomy was performed at
T10-11 with spinal cord stimulator electrodes at T8 and T9 as shown in the figure. The patient also
had a history of chronic opioid use and was opioid tolerant. Other medical history included
hypertension and asthma.
[Fluorosopic image of spinal cord stimulator]
A thoracic epidural was deferred preoperatively due to the presence of spinal cord stimulator at the
desired site of puncture and the patient consented for a post-op regional technique if necessary. The
intraoperative period was significant for high opioid utilization and the patient was started on a
Ketamine infusion intra-operatively after a bolus dose. The patient was placed on a Dilaudid PCA (0.3
mg every 10 minutes) and ketamine infusion at 10 mg/hr postoperatively. On Postoperative day 1, he
had a pain score of 4-5 at rest and 9-10 with activity. He was not interested in regional analgesia until
he tried to ambulate which he was not able to tolerate. He consented for bilateral paravertebral
catheters which were placed under ultrasound guidance by parasagittal technique at T7 - T8 level.
Twenty ml of 0.25% Bupivacaine was injected through each catheter and an infusion of 0.2%
Ropivacaine with Epinephrine was started at 9ml/hr through each catheter.
The patient had significant pain relief with Pain score of 2 -3 at rest and 5-6 with activity. He was able
to ambulate with assistance which he was not able to do before the procedure. The catheters were
th
removed on the 6 postoperative day.
Discussion: Patients undergoing major abdominal surgery often receive a continuous epidural
infusion for postoperative analgesia. However, when epidural analgesia is unwanted or
contraindicated, the administration of parenteral opioids is the usual means used to relieve pain. In an
opioid tolerant patient, pain control following major abdominal surgery without a regional anesthetic
technique can be challenging.
Bilateral paravertebral blocks can provide high quality analgesia and have been used successfully in
the thoracic and abdominal regions as an alternative to central neuraxial blockade (1). Adjuvants may
be particularly useful in opioid tolerant patients; the most thoroughly studied adjuvant is ketamine. In a
Cochrane review, 27 of 37 trials found that perioperative subanaesthetic dose of ketamine reduced
rescue analgesic requirements or pain intensity, or both (2). Postoperative pain relief should be
carefully tailored in these cases by means of a management plan that notes previous spinal
instrumentation and opioid tolerance.
References:
1. Richardson J etal.Br J Anaesth. 2011 Feb; 106(2):164-71
2. Bell RF etal. Cochrane Database Syst Rev. 2006 Jan ;(1):CD004603
A240
EPIDURAL ANESTHESIA FOR CESAREAN SECTION IN A PARTURIENT WITH INTRACRANIAL
TUMOR
H. Skiff, S. Cohen, S. Shah, J. Grayson, A. Mohiuddin, S. Bhasin, R. Chhokra
Anesthesiology, Robert Wood Johnson University Hospital-UMDNJ, New Brunswick, NJ, USA
This 33-year-old white parturient ( Height 165 cm, weight 70 kg) was scheduled for elective CS to be
followed two days later by a scheduled elective craniotomy for removal of left frontal lobe tumor. She
was afebrile, BP 110/70. HR 80, had muscle weakness of the right face, arm and leg without trouble
swallowing. She had slight slurred speech, and denied headache or photophobia. Her neurosurgeon
reported a normal intracranial pressure without midline shift and preferred an epidural anesthesia for
her CS, which would be, followed two days later by craniotomy. The risks and the benefits of epidural
and general anesthesia were explained to the patient and her husband and they preferred epidural
anesthesia.
The epidural space was located at L3-4 interspace using 17g Hustead needle in right lateral decubitus
position. The stylet was reinserted upon reaching ligamentum flavum each time the needle was
[1]
advanced 1-2 mm into the epidural space to reduce the risk of unintentional dural puncture .
Following LOR to air injection, 3,5,5 and 5 ml 2 % lidocaine with 5mcg/ml epinephrine and 5 mcg/ml
[2]
fentanyl was administered by gravity technique via 22 inches extension tube into the needle. A 19g
Arrow open-end tip catheter placed 4 cm in the epidural space. She had bilateral excellent L3-S5
epidural block for an uneventful cesarean section of a healthy but premature female (31 wks) with
1
5
Apgar scores of 8 and 8 . She received 2400 ml of LR solution, had an estimated blood loss of 800
ml and urine output of 800 ml and had stable vital signs throughout the operation. Following an
uneventful course in the PACU, she was transferred to the surgical intensive care unit with epiduralPCA ropivacaine 0.025% with fentanyl 3 mcg/ml and epinephrine1 mcg/ml, 15 ml/hr, 4 ml PCA dose
with lockout time of 10 min. The following day she had an episode of seizures, was intubated,
connected to a ventilator and the epidural catheter was removed. The next day she underwent
craniotomy with only partial removal of rapidly growing tumor. In the postoperative period the
treatment of her persistent increased intracranial pressure was unsuccessful. Two day after surgery
she was declared brain dead and care was subsequently withdrawn.
Summary: There are no guidelines for the optimal time for craniotomy in the pregnant patient with
intracranial tumor. Neurosurgery is usually delayed until after delivery. In our case, upon insertion of
the epidural catheter, there was no clinical evidence of increased intracranial pressure. We still made
every effort to reduce the risk of accidental dural puncture by performing the block in lateral decubitus
position, reinserting the stylet upon each advancement of the needle, administering the local
anesthetic by gravity technique and applying Arrow catheter. The aggressive nature of the tumor
caused this bad outcome. We suggest that epidural block may still be a viable option for parturients
with intracranial tumors and normal ICP admitted for labor and delivery.
References:
1. Cohen S, et al. Anesthesiology 2003; 99:A1161.
2. Cohen S, et al. Clin Anesth 1997; 9:623-628.
A241
GABAPENTIN FOR CHRONIC REFRACTORY NEUROPATHIC PAIN SECONDARY TO
NEUROBORRELIOSIS
A. Solanki, J. Nagda
Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard
University, Boston, MA, USA
Introduction: Persistence of pain even after appropriate treatment of neuroborreliosis is potentially a
severe and debilitating complication of Lyme disease. Both, the etiopathogenesis and management of
this refractory pain are not well defined. Case reports of successful treatment of the painful
component of neuroborreliosis are lacking in literature. We describe a rare case of refractory painful
neuroborreliosis successfully treated with gabapentin.
Case presentation: A 68 year old male resident of Connecticut with no significant past medical
history was admitted to the hospital with 4 weeks history of progressive torso numbness, back pain
radiating to the legs, and proximal leg weakness. This lower extremity weakness rapidly progressed to
paraplegia which was present upon arrival to the hospital. Pain was poorly controlled with NSAIDs.
There was no history of tick bite or any rash in the recent past. No history of fever, dysuria, trauma,
headache, bladder or bowel incontinence was noted.His vitals were stable. Clinical exam revealed
lower extremity motor deficit with absent tendon reflexes and babinski reflex. Rest of the exam was
unremarkable. Routine laboratory evaluation was non contributory. Magnetic resonance imaging
(MRI) of back and Computed tomography (CT) of head and abdomen did not reveal any abnormality.
ELISA for Lyme antibodies (Ab) was positive which was then confirmed with positive serum IgM and
IgG Lyme Ab by Western Blot. The patient was diagnosed with neuroborreliosis. After 3 weeks of
ceftriaxone therapy, his flank and groin pain resolved along with complete resolution of paraplegia. He
was discharged home with opioids for persistent back pain.The patient presented to the Pain Center
after 3 weeks of failed trial of opioids with intense pins/needles sensation in T8-T12 dermatomal
distribution and significant hyperhydrosis on the affected dermatomes. Physical exam revealed
thoracolumbar neuropathy. The clinical presentation and physical exam findings were suggestive of
an inflammatory radiculopathy which was most likely due to Lyme disease. Given the neuropathic
model of pain, patient was initially prescribed gabapentin 100 mg daily. Within 3 weeks of escalating
doses of gabapentin, his painful radiculitis completely resolved. Till date, his pain is well controlled
with gabapentin.
Discussion: Lyme disease is the most frequently reported arthropod borne infection of nervous
system in Europe and USA. Neuropathic pain persists in 10-15% cases of neuroborreliosis even after
1
adequate treatment . Pain is usually refractory and no recommendation is available for its treatment.
Our patient was given gabapentin in escalating doses with complete resolution of symptoms over 3
weeks. Our experience with this case indicates that gabapentin may be tried as the first agent in this
situation. Further studies are required for studying the treatment of refractory neuropathic pain of
neuroborreliosis.
References: 1. Weissenbacher S, Ring J, Hofmann H. Gabapentin for the symptomatic treatment of
chronic neuropathic pain in patients with late-stage lyme borreliosis: a pilot study. Dermatology.
2005;211(2):123-7.
A242
COLOR DOPPLER GUIDED CONFIRMATION AND LOCALIZATION OF EPIDURAL CATHETER
A. Sonny, S. Mohamed, H. Elsharkawy
Anesthesiology, Cleveland Clinic, Cleveland, OH, USA
Introduction: Epidural analgesia is a widely used neuraxial method for postoperative analgesia.
Traditionally, loss of resistance (LOR) to air or saline is used to identify epidural space. However,
primary failure rate can exceed 10%. Thoracic paravertebral spaces, gaps in ligamentum flavum and
muscle layers can lead to false LOR and subsequent inaccurate placement of epidural catheter.
Although clinical response to local anesthetic in the form of dermatomal anesthesia is the “gold
standard” to correct placement, it takes time to elicit and could be difficult to perform in a patient who
has received sedation for the procedure. Here we describe a novel technique using color Doppler to
confirm and identify position of the catheter in the epidural space.
Case: We present a 65 year old male patient, scheduled for preoperative placement of lower thoracic
epidural catheter for upcoming exploratory laparotomy. Patient approval was obtained for
presentation. We anticipated difficulty in epidural placement due to inability to reliably identify
landmarks, due to excess subcutaneous fat and also moderate scoliosis identified by X-ray. Using 2-5
MHz curvilinear ultrasound probe, we identified the landmarks and the depth from skin to the
duramater. Using the paramedian oblique sagittal view and in plane needle insertion, an echogenic 18
gauge Touhy needle was advanced into the T8-9 interspace under real time ultrasound guidance.
Epidural space was identified utilizing loss of resistance to saline. Subsequently, epidural catheter
was easily advanced into the epidural space through the needle. About 5 cm of the catheter was left
in the space.
Color Doppler Ultrasound images were obtained, in the paramedian sagittal oblique view, at the level
of insertion of the epidural catheter, while injecting saline through the catheter. We were able to
identify the path of the catheter from the skin to its entry into the epidural space, thus confirming its
correct placement.
[Image 1]
Further images were obtained above and below the insertion point. The flow of saline, signifying the
path of the catheter, could be easily identified within the epidural space.
[Image 2]
This provided us information on the path of the catheter inside the epidural space and potentially
location of the catheter tip.
Discussion: Various methods have been described in literature to confirm and localize the position of
epidural catheter after placement. These include epidural stimulation test, epidural pressure waveform
analysis and injecting dye with fluoroscopic confirmation. These are cumbersome to perform in a
perioperative setting and lack sensitivity, and thus have not gained popularity. Ultrasound has been
described to look at the spread of the local anesthetic in the epidural space, by monitoring the
movement of dura as the epidural space expands. But these are difficult to obtain at the thoracic level
especially in the adults. With the easy availability of ultrasonography in most regional anesthesia
settings, color Doppler imaging could be a quick and easy way to confirm position and follow path of
the catheter in epidural space.
A243
JUST ANOTHER NERVE BLOCK...
R. Sreedharan, H. Elsharkawy, W. Ali Sakr Esa
Cleveland Clinic Foundation, Cleveland, OH, USA
Eventration of diaphragm is an abnormally high position of part or the entire diaphragm, usually
associated with a marked decrease in muscle fibers and a membranous appearance of the abnormal
area. Majority of the adult patients with eventration of the diaphragm are asymptomatic. We describe
a case of a patient who had an asymptomatic eventration of the left diaphragm and received a
supraclavicular nerve block for a shoulder surgery on the right and developed acute respiratory
compromise.
79 year old male with a significant past medical history of CAD, was scheduled for a right sided
reverse shoulder arthroplasty. He did not have a history of any respiratory symptoms. Preoperatively
a right supraclavicular(SC) nerve catheter was inserted under ultrasound guidance using a 17 G
tuohy needle. A total of 14 cc of local anesthetic (7cc 2%mepivicaine+7 cc 0.5% ropivicaine) was
given through the catheter. Towards the end of the procedure, the SC catheter infusion was started
with ropivicaine 0.2% basal rate of 8 cc, demand dose of 12 cc every 60 minutes. Few minutes after
extubation there was desaturation to the mid 80's. Hemodynamics were stable. The differentials at
this point included postoperative atelectasis, myocardial ischemia, fluid overload or phrenic nerve
palsy due to the SC nerve block. The SC infusion was stopped and he was transferred to the post
anesthesia care unit. A CXR showed a significant pleural effusion on the right side. Postoperative
EKG and cardiac enzymes were normal. Diaphragmatic function assessment at the bedside was done
using an ultrasound. There was a significant restriction of diaphragmatic movement on the right side.
Of note the left side diaphragmatic movement was significantly restricted as well (Images below)
Right side - midclavicular line - No pneumothorax. M mode - restricted diaphragmatic movement with
quiet breathing
[USG image- right side of diaphragm ]
Left side- anterior axillary line . M mode- restricted diaphragmatic movement with sniffing and quiet
breathing
[USG image- left side of diaphragm]
On review of his older records his CXR from a year ago did mention the presence of eventration of his
diaphragm on the left which the patient was not aware of. There were multiple episodes of
desaturation over the next day in spite of attempts to restart the infusion at a lower rate. Evaluation
during these episodes revealed desaturation with hypercapnia. Hence the decision was made to
remove the catheter. There were no more episodes of respiratory compromise.
The SC approach is associated with phrenic nerve palsy in 63% of the patients. In our patient, in the
presence of an impaired diaphragmatic function on the left due to eventration, a right sided brachial
plexus block with phrenic nerve involvement mostly probably caused his respiratory compromise. In
conclusion, a preoperative or postoperative ultrasound assessment of the diaphragm before doing a
brachial plexus block could be fairly simple, quick and could possibly avoid a potentially fatal
complication.
Verbal consent has been obtained from the patient for this presentation
A244
CONTINUOUS EPIDURAL ANESTHESIA AS THE PRIMARY ANESTHETIC FOR MODIFIED
RADICAL MASTECTOMY IN A PATIENT WITH PULMONARY FIBROSIS
A.T. Tantoco, D. Elmofty
Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL, USA
Introduction: Restrictive lung disease is a known risk factor for post-operative pulmonary
complications in patients who undergo a general endotracheal anesthetic technique. Continuous
epidural anesthesia and analgesia is known to support improved pulmonary mechanics when
compared to general anesthetic techniques. More recently, anesthetic technique may also have an
effect on breast cancer recurrence. Here, we report a case of a patient with extensive pulmonary
fibrosis undergoing mastectomy for newly diagnosed breast cancer, the second in our case series of
mastectomies performed using continuous thoracic epidural anesthesia.
Case report: The patient was a 50 year old female who presented for modified radical mastectomy
and axillary lymph node dissection for intraductal carcinoma. She had a history of fibrotic lung disease
felt to be secondary to mantle radiation and bleomycin toxicity for Hodgkin's lymphoma several years
prior. At baseline, she used nocturnal supplemental oxygen and experienced dyspnea after walking
up one flight of stairs. Pre-operative PFTs displayed decreased FEV1 and FVC (34% and 37%
predicted, respectively). Given the high risk of pulmonary complications of a general endotracheal
anesthetic, the procedure was performed using continuous thoracic epidural anesthesia with
monitored anesthesia care. A 17 G Tuohy needle was inserted with the aide of fluoroscopy in the T45 epidural space using a L paramedian technique with loss of resistance at 3.5 cm. An epidural
catheter was then threaded to the T2-3 interspace and the tip position was confirmed with an
extradural myelogram demonstrating appropriate epidural spread. 1.5% lidocaine with 1:200,000
epinephrine was administered through the epidural catheter intermittently throughout the procedure;
an intravenous infusion of 10:1 propofol/ketamine was used for sedation.
Discussion: Epidural anesthesia and analgesia has many advantages including improving postoperative VC and FRC and reducing the rate of postoperative pulmonary complications. In a metaanalysis including 141 randomized trials with almost 10,000 patients, Rodgers et al described a
reduction in post-operataive pneumonia by 39% and a reduction of mortality of about one third when
compared to a systemic analgesic regimen. In addition to the advantages of improved decreased
pulmonary morbidity, recent interest has described the possible effects of anesthetic technique in
relation to the pathophysiology of malignancy. General anesthesia and opioid analgesia, by transient
alterations in the immune system, may potentially increase the incidence of cancer recurrence.
Deegan CA et al described how patients receiving propofol/paravertebral anesthesia for breast cancer
surgery significantly inhibited the proliferation of an ER-negative cell line in vitro as well as altering
both pro- and anti-tumorigenic cytokines in comparison to those patients who received a
sevoflurane/opioid anesthetic.
References:
Rodgers A et al (2002). Reduction of postoperative mortality and morbidity with epidural or spinal
anaesthesia: results from overview of randomized trials. Br Med J 321:1-12 Deegan CA et al (2009).
Effect of anaesthetic technique on oestrogen receptor-negative breast cancer cell function in vitro.
BJA 10 (5) 685-90.
A245
ULTRASOUND GUIDANCE FOR BILATERAL SUPRACLAVICULAR BLOCK IN A PATIENT WITH
ELECTROCUTION INJURY: CASE REPORT
P.R. Telang, B. Gelpi, C.G. Samuelson, S. Billiodeaux, J.D. Adair
Anesthesiology, Louisiana State University, Shreveport Health System, Shreveport, LA, USA
Introduction: Electrocution injuries are unique due a to low mortality, but a significant short and long
term morbidity(Hussmann). Neurological complications are common due to the initial death of the
nerve cells, and fibrosis of the remaining nerve tissue. Damage to inhibitory neurons and growth of
excitatory afferent neurons leads to the development of neuropathic symptoms, and increases the
possibility of the developing chronic pain syndrome(CPS)(Searle). Controlling pain is a priority both for
management of acute pain and for reducing the risk of developing CPS. This study describes the
utility and clinical considerations of ultrasound guidanced(US) placement of bilateral supraclivular
catheters for pain control in a patient with electrocution injury.
Case description: A 29 year old man suffered bilateral upper extremity injuries after grabbing a high
voltage power line. Severe tissue damage along with sensory and motor deficits in both upper
extremities, andwith wounds in both axilla. necessitated bilateral below elbow amputations. His
postoperative course was complicated by pain refractory to IV narcotics. Initial attempts at brachial
plexus blockade were unsuccessful via nerve stimulation technique(NS).
Due to the high rate of phrenic nerve paralysis with interscalene blocks, we decided to place bilateral
supraclavicualr catheters using US.
After discussing the risks and benefits, a left supraclavicular block was performed. The patient was
monitored for relief of symptoms and complications. Due to continued pain, this procedure was
repeated on the right with similar monitoring. This efectively controlled the patient´s pain. The
remainder of his hospitalization was uneventful.
Discussion: Supraclavicular nerve blocks can be performed by eliciting paresthesia, NS, or
US(Mirza). The first two techniques may not be reliable in identifying the brachial plexus due to
extensive nerve damage caused by electrical trauma. Prior attempts using NS for placement were
unsuccessful despite increasing the current level. Furthermore, our patient had bilateral below elbow
amputations which complicated anatomical correlation to the twitch response. US allows real-time
visualization of the anatomy and has been shown to be associated with superior rates of block
success, physician confidence and lower rates of complication(Abrahams,Yuan)
This case highlights the need for acute pain control in patients with electrical injury. In addition it
defines a group of patients in whom NS blockade may not be possible. Finally it stresses the potential
complications of bilateral blockade and the need for patient monitoring.
Conclusion: Pain control in patients with electrocution injuries can prove difficult. Traditional
approcahes at nerve blockcade may not be possible, and as such US should be considered. All
patients undergoing continuous blockade should be monitored for complications.
References:
- Hussmann J, et.al. Electrical injuries--morbidity, outcome and treatment rationale. Burns.1995
Nov;21(7):530-5
- Searle, RD, Simpson KH. Chronic Post Surgical Pain. Continuing Education in Anaesthesia. Critical
Care and Pain. Vol 10 Number 1 2010
- Mirza F, et al. Ultrasound-guided regional anesthesia for procedures of the upper extremity.
Anesthesiol Res Pract. 2011. Epub 2011 May 30.
- Abrahams MS, et al. Ultrasound guidance compared with electrical neurostimulation for peripheral
nerve block: a systematic review and meta-analysis of randomized controlled trials. Br J Anaesth.
2009 Mar;102(3):408-17.
A246
THE USE OF REGIONAL BLOCK IN A PATIENT WITH PHANTOM LIMB PAIN
A. Tharian, S. Klier, K.D. Candido, N.N. Knezevic
1
2
Anesthesiology and Pain Medicine, Advocate Illinois Masonic Medical Center, Anesthesiology,
University of Illinois at Chicago, Chicago, IL, USA
Introduction: The reported prevalence of phantom pain varies widely in the literature, but today most
1
studies agree that 60% - 80% of all amputees experience phantom pain following loss of limb.
Despite extensive research in the area, the mechanism underlying phantom limb pain is not fully
known and its treatment remains a major challenge to pain management clinicians.
Case description: A healthy 68-year-old female developed progressive left shoulder pain over 2
years, which was attributed to a rotator cuff tear. However, surgical arthroscopy identified a mass
lesion and biopsy specimen reported myoepithelioma of the bone affecting the shoulder joint. A left
forequarter amputation was done under general anesthesia and an interscalene nerve block using 30
mL of 0.5% Ropivacaine for post operative analgesia was performed. She developed persistent
excruciating pain of left arm and forearm, 8-10 hours after the sensory block dissipated. At POD #1
she developed a “crushing sensation” in the non-existent left hand. Amitriptyline, Gabapentin,
Oxycontin and Fentanyl patches failed to minimally control pain. Analgesic medications failed to
provide longer than 6-8 hours pain relief. Supraclavicular nerve block was done under ultrasound
guidance with 20 ml of 0.2% Ropivacaine by using an insulated 5 cm Pajunk needle. The numeric
pain score dropped from 10/10 to 2/10 after the supraclavicular block and remained at this level for 72
hours, after which it gradually increased to 4/10, but not higher. She was able to discontinue use of
Amitriptyline and Gabapentin, and to wean gradually off of the Fentanyl patch therapy.
Conclusion: No single therapy has been found to be uniformly effective for the successful treatment
for phantom limb pain and multiple treatments maybe combined in a true multi-modal fashion to
achieve the optimal result. This case report proposes a timely implementation of a brachial plexus
regional nerve block as one of the interventional therapies which can be considered for upper
extremity phantom pain relief.
Reference: 1. Birbaumer, N. et al. Effects of regional anesthesia on phantom limb pain are mirrored
in changes in cortical reorganization J Neurosci 1997;17: 5503-8.
A247
A CASE OF WINGED SCAPULA FOLLOWING THE PLACEMENT OF AN INTERSCALENE
PERINEURAL CONTINUOUS CATHETER
S.E. Thomas, E. DeBusk, J.B. Winchester, G.V. Hickman
1
2
Regional Anesthesia Fellowship, BLOCKJOCKS Research and Education Foundation, The
Andrews Institute ASC, Gulf Breeze, FL, USA
Introduction: As an ambulatory surgery center, we perform interscalene catheters for shoulder
surgery. To minimize the possibility of phrenic nerve blockade we employ a posterior approach and in
combination with a low volume technique, we have observed a significant decrease in the incidence
of postoperative respiratory complications while maintaining a nearly 100% success rate for
postoperative analgesia. We feel that traversing the middle scalene muscle provides a relatively
unobstructed path to the posterior aspect of the cervical roots within the interscalene groove and
avoids many of the vital structures encountered with an anterior approach including the phrenic nerve
itself, the carotid artery, and the internal jugular vein. We are unaware of any outcome data that
supports injury to the dorsal scapular and long thoracic nerves related to an interscalene block. We
have a challenging case of a patient who suffered long thoracic nerve injury following shoulder
surgery, presumably as a result of interscalene catheter placement.
Materials and methods: The patient underwent a right rotator cuff repair with subacrominal
decompression and bicep tendon repair. Her preoperative assessment demonstrated shoulder pain
but no significant motor or sensory deficits in her upper extremity.On the day of surgery, an
experienced anesthesiologist uneventfully placed in pre op an interscalene catheter using ultrasoundguidance (without concomitant nerve stimulation)under midazolam sedation.Her surgery and PACU
stay were uneventful and she was discharged home with the indwelling catheter and elastomeric
pump.She remained comfortable and denied any adverse symptoms for as long as the catheter
remained in place. She removed the catheter on post-operative day 3 without difficulty. During her
routine two week postoperative visit with the surgeon she was noted to have significant shoulder
weakness, poor scapular stabilization and significant medial scapular winging on the right side only.
She was felt to have had good operative result and was referred for further evaluation by a physiatrist.
Results: The EMG study demonstrated severe incomplete right long thoracic neuropathy. Although
her prognosis is good for regaining most or all of her strength and function her neurologic recovery is
expected to take between 18 and 20 months and she will need to undergo rehabilitation for several
months.
Discussions: We were unable to identify any other confirmed cases of nerve block-related long
thoracic or dorsal scapular nerve injuries in the regional anesthesia literature. It remains unclear to us
whether the addition of nerve stimulation to the use of ultrasound would effectively reduce the
likelihood of injury to these nerves by allowing safe needle redirection if long thoracic or dorsal
scapular nerve twitch is elicited absent ultrasound visualization during needle passage. One could
argue that systematic ultrasonographic +/- nerve stimulator assisted identification of these nerves, or
at the very least awareness of their presence, could help avoid adverse outcomes such as this one.
References: Hanson N, Auyong D,Systematic Ultrasound Identification of the Dorsal Scapular and
Long Thoracic Nerves During Interscalene Block, Regional Anesthesia & Pain Medicine. 38(1):54-57,
January/February 2013
Conflict of Interest:
Debusk-BBraun Medical
Winchester-BBraun Medical, Kimberly Clark, Pacira
Hickman-BBraun Medical, Kimberly Clark, Pacira
The patient consented / IRB approved.
A248
AN ATYPICAL RESPONSE TO INTRATHECAL BACLOFEN LIMITS THE THERAPEUTIC
OPTIONS FOR THE MANAGEMENT OF A PATIENT WITH SPASTICITY RELATED PAIN: A CASE
REPORT
B.F. Thompson, M.W. Christopherson
Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN, USA
Case description: A 34 year-old women with a past medical history significant for a slowly
progressive spastic paraparesis secondary to chorionic myelopathy presented for management of
painful spasms. She had failed previous treatment with oral Baclofen and Zanaflex. Physical exam
revealed scissoring gait pattern, 4+/4+ lower extremity reflexes, bilateral non-sustained clonus, and
Modified Ashworth Score of 2 at her bilateral ankles and knees and 3 at her hips. An intrathecal test
dose bolus injection of baclofen was scheduled in hopes that she may have success with implantable
pump system.
She underwent a fluoroscopically-guided intrathecal baclofen test dose injection of 75 mcg bolus
given over 3 minutes at the L3-L4 level using a 20-gauge spinal needle. Thirty minutes following the
procedure she developed an acute 10/10, holocephalic headache and nausea without decrement
from the upright to supine position. Neurologic examination remained unchanged with the exception
of improved lower extremity tone. Her headache slowly improved over the subsequent five days.
The immediate onset and nature of her pain, unaffected by change in position, was inconsistent with a
diagnosis of a post-dural puncture headache. It was, instead, concluded that she had primary
intrathecal baclofen insensitivity. Repeating the injection at a reduced dose could have confirmed this
diagnosis since her symptoms would be expected to recur in a dose-independent fashion. However,
our clinical suspicion was high enough not to justify the potential discomfort of a second injection.
Instead, an alternative management strategy was pursued.
Discussion: It is well known that intrathecal baclofen bolus injections can cause spinal headaches
and lower seizure thresholds, leading to acute neurologic sequelae. The literature finds that up to
10% of patients with intrathecal baclofen pumps report intermittent headaches; however, these are
generally described as mild and are associated with other common symptoms of hypotonia and
somnolence suggesting a dose-dependent effect. To our knowledge, this is the first documented case
of an acute post-procedure headache secondary to primary baclofen insensitivity.
Conclusion: Medication insensitivities can be easily confused with procedure-related symptoms,
particularly given that post-dural headaches are relatively common. It is important to consider the
timing and quality of the patient's symptoms. If the clinical signs suggest medication insensitivity, a
second test dose should be avoided to prevent unnecessary discomfort.
A249
REDUCTION OF TEMPOROMANDIBULAR JOINT DISLOCATION WITH KETAMINE
1
1
1
2
S.K. Tuncer , U. Kaldirim , M. Toygar , E. Eyi , M. Durusu
1
2
1
3
Emergency Medicine, Forensic Medicine, Gulhane Military Medical Academy, Ankara, Emergency
Medicine, Hakkari Military Hospital, Hakkari, Turkey
Introduction: Temporomandibular joint (TMJ) dislocations take place among Maxillofacial
Emergencies. Translation and rotation is achieved by articulation of mandibular condyle with temporal
bone in the mandibular fossa. These two bones are separated by an articular disc. In most intances,
the disc is displaced anteriorly (1). More commonly, dislocation occurs bilaterally and radiographs or
CT may be necessary for diagnosis (2). In the treatment of patients with no other clinical findings
suggestive of fracture, reduction is adequate. Reduction is achieved by grasping mandible with both
hands and resting thumbs inside the mouth on the molars, then applying downward and backward (1).
Analgesia, muscle relaxation, local anesthesia and sometimes sedation are advised to promote
successful manual reduction (3). These cases highlight the importance of providing the patient with
adequate sedation with Ketamine when attempting the reduction of TMJ dislocations.
Case 1: 21-year-old patient with jaw pain and limited movement due to a punch stroke was admitted
to emergency department. Physical examination revealed limitation of movement of jaw, tenderness,
spasm, and deformity in TMJ. Radiologic assay revealed bilateral temporomandibular anterior
dislocation. Instead of reduction, procedural sedation was performed because of patients' lack of
orientation, spasm and pain. After providing adequate sedation with intravenous Ketamine 70mg;
reduction was successfully performed at a time. Patient was discharged after follow-up.
Case 2: 28-year-old woman was presented with jaw pain and limited movement of jaw due to trauma.
Physical examination revealed limitation of movement of jaw, bilateral TMJ tenderness, pain.
Radiologic assay revealed bilateral temporomandibular anterior dislocation. Because of patients'
agitation and pain; reduction wasn´t performed. After monitorization with the help of Ketamine 55mg
administration; adequate sedation was achieved. Reduction was performed with success in a short
time. Patient was discharged after follow-up.
Discussion: Reduction of TMJ is generally achieved by applying downward and backward pressure
on patient´s lower molar teeth. Coordination and adaptation problems due to pain and agitation are
the inhibiting factors for reduction. Troubling reductions and recurrent unsuccessful attempts for
reductions may result in deformity of TMJ. Reduction is unlikely to be successful without adequate
analgesia and sedation due to pain or agitation. Therefore analgesia and sedation are advised to
promote successful manual reduction. Agent of choice includes Ketamine if there isn´t any
contraindication (6). We suggest fingers should be gloved with adequately thick gauze taped securely
on both thumbs to prevent injury.
References:
1. Chan TC, Harrigan RA, Ufberg J, Vilke GM. Mandibular reduction. J Emerg Med. 2008
May;34(4):435-40.
2. Brooks SL, Brand JW, Gibbs SJ, et al: Imaging of the temporomandibular joint: a position paper of
the American Academy of Oral and Maxillofacial Radiology. Oral Surg Oral Med Oral Pathol Oral
Radiol Endod 83: 609, 1997.
3. Andrew L. Y, Junad K, Davis C. T. Samuel Y. P. Q. Use of Masseteric and Deep Temporal Nerve
Blocks for Reduction of Mandibular Dislocation. Anesth Prog 56:9-13 2009
4. Reuben J. Strayer MD, Lewis S. Nelson MD, Adverse events associated with ketamine for
procedural sedation in adults, AJEM (2008) 26, 985-1028
A250
CONTINUOUS SPINAL ANESTHESIA AND STREAMING MOVIE FOR A PATIENT WITH
MULTIPLE COMORBIDITIES UNDERGOING VASCULAR SURGERY
O. Viktorsdottir, J.E. Charnin, R.M. Allain
1
2
Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of
Anesthesiology, St. Elizabeth's Medical Center. Tufts University, Boston, MA, USA
Introduction: We report a case of an elderly man with occlusive vascular disease, critical aortic
stenosis, pulmonary hypertension and unstable cervical spine fracture undergoing an attempted
femoral-popliteal bypass graft. The accommodation for hemodynamic and airway issues produced the
complexity of this case.
Case report: An 87 year old ASA Class 4 patient with history of hypertension, hyperlipidemia,
coronary artery disease with 4 BMS placed 7 months ago, severe aortic stenosis awaiting
percutaneous transcatheter aortic-valve replacement, severe pulmonary hypertension, atrial
fibrillation, insulin dependent diabetes and significant history of anxiety and agitation with procedures,
presented for right femoral-popliteal bypass graft for non-healing leg ulcer. A transthoracic
percutateous aortic valve replacement was deemed unsafe given high risk for infection while his nonhealing right leg ulcer persisted. The patient refused amputation of the leg as recommended by the
vascular surgeon and wished to proceed with a high-risk attempt of revascularization of his right leg.
The night before the scheduled surgery, the patient sustained a fall resulting in an unstable cervical
fracture of C1 and C2. The patient was not deemed a candidate for fixation due to his poor
cardiovascular health and conservative management with Aspen collar for 8 weeks was
recommended. The surgery was rescheduled two weeks after the neck fracture and the patient
underwent an attempted right femoral popliteal bypass graft under continuous spinal anesthesia. The
spinal catheter placement was challenging because of scoliosis but was successful in the sitting
position. We used a mixture of 0.1% bupivacaine and 1.5% mepivacaine. Operative conditions were
excellent. A central line was placed before the start of the spinal anesthetic and low dose
norepinephrine infusion was used intraoperatively to maintain SVR. No additional sedatives or
narcotics were administered. To distract the highly anxious patient, a movie of patient's choice was
streamed to an iPad supported in a position above the patient's chest with a metal stand mounted to
the bed with a Clark Adapter. The patient remained hemodynamically stable throughout the case.
Unfortunately, revacularization was not technically possible and the patient returned 3 days later for
below-knee-amputation where the same anesthetic technique was again successfully used with the
addition of intrathecal morphine for postoperative pain control.
Discussion: We report a case of a vascular patient with multiple comorbitites undergoing an
attempted femoral-popliteal bypass graft. The patient presented a number of anesthetic challenges
which lead to an anesthetic plan of continuous spinal anesthesia. Instead of administering sedatives
for monitored anesthesia care, we successfully managed to stay away from sedatives altogether by
streaming a movie to an iPad, mounted above patient's chest.
A251
SUBCUTANEOUS BOTULINUM TOXIN A INJECTION FOR TREATMENT OF A CASE OF FACIAL
POST-HERPETIC NEURALGIA
P. Vu, S. Jones
Department of Anesthesiology & Pain Management, University of Texas Southwestern Medical
School, Dallas, TX, USA
Introduction: Post-herpetic neuralgia (PHN) is a pain condition caused by the herpes zoster virus
that typically presents in a dermatomal distribution. It has been conventionally treated with an array of
medications including anticonvulsants, antidepressants, opioids, and topical lidocaine and capsaicin.
We present a case of significant pain relief of PHN with Botulinum Toxin A (BTX-A).
Case description: A 64 year old female with a past medical history of hypertension and diabetes
mellitus type II presented for treatment of 10 month history of PHN in the right V3 (mandibular)
distribution. Pain was 8-10/10 on a Visual Analog Scale (VAS). Allodynia was noted along the right
lower face and tongue in the V3 distribution. The patient had been trialed on multiple anticonvulsants,
antidepressants, opioids, non-steroidal anti-inflammatories, muscle relaxants, and topical ointments
with minimal relief. Based on the clinical presentation and failed trials of multiple medications, BTX-A
was trialed. BTX-A was reconstituted at 100 units with 20 mL of normal saline to a concentration of 5
units/mL. A grid of 2x2 cm squares was drawn and 1 mL of BTX-A was injected aseptically at each
2x2cm target with a 30 gauge 0.5 inch needle. Eighty units of BTX-A were injected among 16 sites. At
one month, significant pain relief was reported with VAS of 3/10 with improved mood and functionality.
She did have mild right buccal weakness and persistent pain in the right tongue, which was not
injected due to risk of dysphagia. Her pain returned in severity approximately 3 months after the
injection.
Discussion: PHN is a pain condition that affects between 5-20% of people following an outbreak of
herpes zoster. Several medications have been used to treat PHN with no single best therapy
emerging. Though BTX-A has been used for treatment of migraine headaches and dystonias, few
reports and studies have cited the use of BTX-A for alleviation of PHN. BTX-A is thought to have both
peripheral and central anti-nociceptive effects through inhibiting release of glutamate, substance P
and calcitonin gene-related protein. Our patient exhibited significant pain relief after BTX-A with
improved function and mood lasting for 3 months. BTX-A appears to be a promising therapy for the
treatment of PHN. Further reports and studies are needed to confirm the efficacy of this emerging
therapy for treatment of facial PHN.
References:
· Xiao L, Mackey S, Hui H, Xong D, Zhang Q, Zhang D. Subcutaneous Injection of Botulinum Toxin A
is Beneficial in Postherpetic Neuralgia. Pain Med 2010 Dec;11(12):1827-33.
· Liu HT, Tsai SK, Kao MC, Hu JS. Botulinum Toxin A Relieved Neuropathic Pain in a Case of PostHerpetic Neuralgia. Pain Med 2006;7:89-91.
A252
A CASE OF ISOLATED FEVER WITH CONTINUOUS EPIDURAL ANALGESIA IN A NONOBSTETRIC SURGICAL PATIENT
P. Vu, J. Kweku, G. Cheng
Department of Anesthesiology & Pain Management, University of Texas Southwestern Medical
School, Dallas, TX, USA
Introduction: Isolated fever with continuous epidural analgesia has been well documented within the
obstetric population. While some mechanisms have been proposed, no exact process has been
identified as the source of these fevers. It is thought that hypothermia occurs with epidural analgesia
in the non-obstetric patient. We present a case of isolated fevers from epidural analgesia in a nonobstetric surgical patient.
Case description: A 57 year old Caucasian female with past medical history of pancreatic cancer
undergoing a pancreaticoduodenectomy presented for a preoperative low-thoracic continuous
epidural for post-operative pain control. The epidural space was identified at the interspace between
th
th
the 8 and 9 vertebrae by loss of resistance technique with air and an epidural catheter was placed
atraumatically with negative test dose for intravascular or intrathecal placement. The epidural was
bolused with 0.25% bupivacaine and the epidural infusion was started intraoperatively. The patient
had an uneventful intraoperative course and was taken to the intensive care unit extubated for closer
monitoring. Four hours after the end of surgery, and twelve hours from epidural placement, the patient
was found to have a temperature of 38.6 degrees Celsius. She had no tachycardia, tachypnea, or
leukocytosis. The patient continued to have fevers on post-operative day (POD) #1 without any other
signs or symptoms of infection. Her pain was well controlled and she had no complaints. Although
suspicion was low, blood and urine cultures were sent to rule out infection. The patient continued to
have isolated fevers with temperature peaking at 39.3 on POD #2 still with no leukocytosis, bandemia,
tachycardia, or tachypnea. Cultures showed no growth and chest x-ray did not show any infiltrates or
consolidation. The source of the fever was thought to be due to the epidural as no other source could
be identified. Decision to remove the epidural was made between the surgical and acute pain
services. The epidural was removed without issue. After epidural removal, the patient's body
temperature decreased to 36.9 within two hours. She continued to have core body temperatures
within normal range throughout the rest of her hospital course with all final cultures being negative.
Discussion: Epidural-related fever in the obstetric patient has been well documented with evidence
supporting maternal inflammatory response from increased pro-inflammatory cytokines. Other
proposed mechanisms include alterations in the thermoregulatory pattern, sympathetic stimulation,
and oxidative stress. Traditionally, epidural analgesia is thought to cause hypothermia, not
hyperthermia in the surgical patient due to sympathectomy-related vasodilation with redistribution of
body heat to the peripheral tissues. However, increased inflammatory response could potentially
explain our patient's fevers in the absence of infection. Our patient exhibited steady temperature
elevation post epidural placement with a peak temperature of 39.3 degrees Celsius. After removal of
the epidural catheter, the patient had a return to normothermia within a few hours further supporting
the belief that the fevers were related to the epidural. Further research is warranted.
References:
- Epidural analgesia and maternal fever: a clinical research update. Curr Opin Anaesthesiol. 2012
- Labor Epidural Analgesia and Maternal Fever. Anesth Analg 2010
A253
EVALUATING THE FEASIBILITY OF TAP BLOCK AS A PRIMARY ANESTHETIC TECHNIQUE
FOR LAPAROTOMY IN HIGH RISK PATIENTS
J.T. Vuong, S.D. Adhikary, P. McQuillan, E. Messaris
1
2
Anesthesiology, Colorectal Surgery, Penn State Hershey Medical Center, Hershey, PA, USA
The anesthetic management of elderly patients undergoing abdominal surgery is focused on
minimizing morbidity and mortality. The physiological changes of aging, in addition to preexisting
comorbidities, necessitate maintaining hemodynamic stability, avoiding hypoxia, and aggressive pain
management. The risk of prolonged intubation favors avoiding airway compromise. Although PCA and
epidural analgesia are useful, they may be contraindicated or technically difficult. Parenteral opioid
administration has been associated with delirium. We present three cases utilizing transversus
abdominis plane (TAP) block as the primary anesthetic for laparotomy.
In the operating room, standard ASA monitors and nasal cannula oxygen were applied. Blocks were
performed after sterile prep and draping using only midazolam and fentanyl for sedation. A real-time
technique utilizing in-plane ultrasound visualization was used.
Case 1: A 92 year old, 64kg woman with sigmoid cancer status post loop colostomy presented with
ostomy prolapse. Her comorbidities included hypertension, carotid disease, previous postoperative
stroke, and coronary artery disease. Medications included a statin, beta blocker, and aspirin.
A TAP block was performed with injection of 40mL of 0.25% bupivacaine in divided doses. During the
1.5 hour surgery, she received 20-25 mcg/kg/min propofol. Surgeons resected 60 centimeters of
bowel and created an end colostomy and mucous fistula.
Case 2: A 66 year old, 115kg man was transferred from an outside hospital on vasopressors for
hypotension during an ulcerative colitis flare. His comorbidities included multivessel CAD, severe
heart failure, AICD for ventricular tachycardia, obstructive sleep apnea, GERD, anemia, and an aortic
aneurysm. Medications included chronic steroids, beta blocker, aspirin, and nitrates. His preoperative
course was complicated by a hospital acquired pneumonia, bilateral pulmonary emboli, and GI bleed
after heparinization.
A TAP block was performed with injection on each side of 30mL of 0.25% ropivicaine and 1%
lidocaine in a 50/50 mix. He received no further sedation during the 1.5h loop ileostomy surgery.
Case 3: A 91 year old, 70kg woman was admitted with gastrointestinal bleeding. Her comorbidities
included atherosclerotic heart disease, valvular dysfunction, AV block, renal insufficiency,
hypertension, and Parkinson's disease. Medications included clopidogrel, aspirin, calcium channel
blocker, beta blocker, nitrates, and anti-Parkinson drugs.
A TAP block utilized 40mL of 0.25% bupivacaine injected in divided doses. During the 3 hour
resection of a large cecal adenocarcinoma, she received 100mcg of fentanyl and 25mcg/kg/min
propofol.
1,2
Mortality for elderly patients undergoing emergency abdominal surgery is significant . Comorbidities,
time from symptom onset to surgery, colorectal surgery, age >80, and malignancy correlate with
2
increasing mortality. Morbidity is highest for the respiratory system (11.5%). We have demonstrated
the efficacy of a TAP block as a surgical anesthetic, avoiding airway manipulation and hemodynamic
instability that might accompany induction. Our block placement required < 30 minutes and one
attempt per patient, by residents as well as an attending anesthesiologist. All patients remained stable
intraoperatively.
References:
1. Jin, F, Chung, F. “Minimizing perioperative adverse events in the elderly.” Br. J. Anaesth. 2001 87
(4): 608-624.
2. Arenal, Juan, BengoecheaBeeby, M. “Mortality associated with emergency abdominal surgery in
the elderly.” Can J Surg. 2003 April; 46(2): 111-116.
A254
DIAGNOSTIC AND THERAPEUTIC OCCIPITAL NERVE BLOCKS FOR REPORTED TRAUMA
INDUCED OCCIPITAL NEURALGIA
J. Walker, S. Howell
1
2
Anesthesia, WVU Healthcare, Morgantown, WV, USA
Chronic headaches can be debilitating for many patients. Headache disorders often have a nebulous
etiology, unpredictable course, and can be difficult to manage. We describe a post-traumatic
headache that began after a motor vehicle collison. The patient sustained multiple injuries including a
scalp laceration and bilateral occipital condyle fractures. Oral agents were unable to quell this
patient's headaches. The diagnosis of occipital neuralgia was suspected based on history and the
patient received dramatic relief after ultrasound guided bilateral occipital nerve blocks.
Case Presentation: A 45 year old, 127 kg male was hospitalized following a motor vehicle accident.
He struck a tree while driving home from work and sustained multiple injuries including traumatic
ventral hernia, traumatic left testicular hematoma, open bilateral superior and inferior pubic rami
fractures, scalp laceration, nasal bone fractures, and bilateral occipital condyle fractures. During his
four week hospital stay, the headaches became more frequent and severe. His past medical history
was only remarkable for type II diabetes mellitus. Hospital medications consisted of Xanax, Cymbalta,
MS-Contin, Percocet, Flexeril, Ultram, metoprolol, simvastatin, and metformin. The headaches were
characterized by sharp pain radiating in posterior to anterior direction. A typical headache episode
was characterized with severe intensity that often lasted several hours. There were no associated
symptoms such as nausea, emesis, or photophobia, or aura. Neurology was consulted for evaluation
and management of these headaches. The diagnosis of occipital neuralgia was made along with
recommendations for bilateral occipital nerve blocks and the addition of gabapentin to his regimen.
Bilateral occipital nerve blocks were performed under ultrasound guidance with 3 mL 0.25%
bupivacaine and epinephrine. The patient reported relief of his headaches and had no complaints of
lingering headaches upon hospital discharge or at his outpatient follow-up visit.
Discussion/References: To be presented on poster.
Funding: No funding or financial interests.
A255
CONTINUOUS POSTOPERATIVE ANALGESIA VIA QUADRATUS LUMBORUM (QL) BLOCK - AN
ALTERNATIVE TO TRANSVERSUS ABDOMINIS PLANE (TAP) BLOCK
N. Yakovleva, M. Visoiu
1
Anesthesiology, Acute Interventional Perioperative Pain Service, University of Pittsburgh Medical
2
Center, Department of Anesthesiology, Acute Interventional Perioperative Pediatric Pain Service,
Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
Continuous administration of local anesthetic via TAPcatheter provides satisfactory postoperative
analgesia for lower abdominal surgery (1,2). We report a case of successfully performed continuous
quadratus lumborum block that provided effective postoperative analgesia in a child requiring
colostomy closure.
The patient is a 5 years old girl, 23 kg, scheduled for colostomy takedown. She had a colostomy after
blunt rectal trauma. Continuous QL block was performed after completion of surgery, with the
patient´s left side up. After cleaning the skin a high frequency probe connected to an S-nerve
ultrasound machine was positioned with a transverse orientation, between iliac crest and costal
margin and QL muscle was visualized (Figure 1). An 18G, 9cm Tuohy needle was oriented in plane,
from anterior to posterior direction, the needle tip was positioned between the anterior border of QL
muscle and its fascia. After negative aspiration, 10 ml of ropivacaine 0.5 % was injected .The needle
held in place and a 20G multi-orifice catheter advanced between the QL muscle and its fascia, left at
13.5 cm at skin. A posterior spread of normal saline solution under QL muscle seen with real time
Doppler imaging, confirming the catheter position.
[Ultrasound image of QL muscle]
The amount of intraoperative opioids was 3.7 mcg /kg of fentanyl, and 0.065 mg/kg of morphine.
Ropivacaine 0.2% infusion started at 5 ml/hr, or 0.43mg/kg/hr.
In 2 hours after the completion of the surgery, the patient was able to ambulate to the bathroom. She
reported complete loss of sensation for touch and temperature across her left abdomen, under
umbilicus, up to midline. She received morphine 0.96 mg/kg, on postoperative day (POD) 1, and 0.48
mg/kg, on POD 2. The minimum pain score was 0/10, the highest pain score was 4/10, with a mean
pain score of 0.42/10 and a median pain score of 1/10. The catheter remained in place for 3 days and
removed after administration of acetaminophen 12 mg/kg, by mouth. The patient was discharged on
POD 4.
To our knowledge, this is the first case reported of continuous QL block.
QL muscle inserts into the lower border of the last rib and by four small tendons into the apices of the
transverse processes of the upper four lumbar vertebrae. Between its fascia and the muscle are the
twelfth thoracic, ilioinguinal and iliohypogastric nerves. The local anesthetic deposited under QL
muscle can be transported into paravertebral space along tissue plane, but also along vascular,
lymphatic and nervous system.
Additional research is required to determine the relative indication of this continuous technique of
local anesthetic infusion compared to TAP and paravertebral.
1. Abdallah FW, Chan VW, Brull R. Transversus abdominis
plane block: a systematic review. Reg Anesth Pain Med 2012;37:193-209.
2. Visoiu M, Boretsky KR, Goyal G, Cladis FP et al. Postoperative analgesia via transversus
abdominis plane (TAP) catheter for small weight children-our initial experience. Pediatr Anesth
2012;22:281-4.
A signed parental consent was obtained.
There is no funding for this research.
The authors reported no conflicts of interest
A256
INSERTION OF PERIPHERAL NERVE CATHETERS USING IN-PLANE NEEDLE INSERTION
WITH LONG AXIS VIEWS OF THE NERVES
M. Yared, W. Ali Sakr Esa, H. Elsharkawy
Cleveland Clinic Foundation, Cleveland, OH, USA
Continuous peripheral nerve catheters are used to provide prolonged post-operative analgesia.
Having the catheter closer to the target nerve may potentially decrease the total volume of local
anesthetic required. Challenges involved with catheter placement include losing visualization of the
catheter tip as it is advanced. The ultrasound-guided catheter insertion approaches include:
1. Needle in-plane, nerve short-axis,
2. Needle out-of-plane, nerve short-axis, and
3. Needle in-plane, nerve long-axis.
With the needle in-plane, nerve short-axis technique, it is easier to identify structures and to find the
catheter tip relative to the nerve. However, since the needle is perpendicular to the nerve, when the
catheter is threaded, it may go beyond the nerve.
With the needle out-of-plane, nerve short-axis approach, the needle and nerve are parallel to each
other which can potentially allow the catheter to stay closer to the nerve when threaded. However, the
needle appears as a dot, which could represent the tip or the shaft, and thus compromise safety.
The needle in-plane and nerve long-axis technique is more technically difficult and potentially more
time consuming to perform because it requires precise alignment of the US beam with the needle and
the nerve and a relatively straight nerve. However, the entire shaft and tip of the needle can be
visualized. It also aligns the nerve, needle, and catheter parallel to each other which potentially allows
for more control over the positioning of the catheter since there is better visualization of the catheter's
advancement in relationship to the nerve.
We performed four cases of peripheral nerve catheter placement using long-axis views of the nerves
while maintaining the needle in-plane with the US. We performed this on the femoral, sciatic, popliteal,
and supraclavicular plexus nerves. First, we identified the nerves in short axis then rotated the probe
90 degrees. With minor probe manipulation, we advanced the needle in-plane and then advanced the
catheter under real time ultrasound guidance 5 cm beyond the tip of the needle. We injected local
anesthetic which showed optimum position of the catheter tip in all cases.
Although the in-plane, long axis approach has rarely been reported, we did not find this technique
difficult to perform. We encountered some difficulty identifying the supraclavicular plexus nerves in
their long axis views. We were successful in using this approach to place the nerve catheters and did
not have any incidence of secondary catheter failure. Future studies are needed to evaluate whether
aligning the catheter and the nerve parallel to each other would prevent migration of the catheter
away from the nerve and decrease the incidence of secondary nerve catheter failure.
[Femoral Nerve Long Axis View]
[Supraclavicular Plexus Nerves in Long-Axis View]
References:
Ilfeld BM, MD, MS, Fredrickson MJ, MD, and Mariano ER, MD, MAS. Ultrasound-Guided Perineural
Catheter Insertion: Three Approaches, but Little Illuminating Date. Reg Anesth Pain Med. 2010; 35(2):
123-126.
Koscielniak-Nielsen ZJ, MD PhD FRCA, Rasmussen H, MD, and Hesselbjerg L, MD. Long-Axis
Ultrasound Imaging of the Nerves and Advancement of Perineural Catheters Under Direct Vision: A
Preliminary Report of Four Cases. Reg Anesth Pain Med. 2008; 33(5): 477-482.
A257
PULMONARY EMBOLISM DURING DORSAL COLUMN STIMULATOR (DCS) TRIAL
Vikas Kumar, M.D., Palak Bipin Turakhia, M.D., Manoj Subbarao Wunnava, M.D.
Anesthesiology, Univ. of North Carolina Hospitals, Chapel Hill, NC, USA
Background
We present the case of an 85 year old female with spinal stenosis, previously responsive to injection
therapy but with declining efficacy over time. The patient had also been trialed on various oral agents
including gabapentin, hydrocodone/APAP and baclofen with minimal relief. She was deemed an
appropriate candidate for a dorsal column stimulator. The patient´s medical history was significant for
breast cancer that had been treated with a partial mastectomy and radiation therapy. She also had a
history of deep venous thromboembolism and was anticoagulated with warfarin. After obtaining
clearance from her hematologist-oncologist, the patient was discontinued from her warfarin therapy
and underwent a percutaneous dorsal column stimulator trial. Two days into the trial, the patient
developed a symptomatic pulmonary embolism (PE) with associated right heart strain and atrial
fibrillation. She was admitted to an outside hospital for stabilization but was started on systemic
anticoagulation with enoxaparin and warfarin prior to the date of her planned trial lead removal. We
ultimately readmitted the patient, transitioned her anticoagulation to a heparin infusion and then pulled
the trial dorsal column stimulator lead once the her coagulation profile had normalized. Specifically,
we adhered to the guidelines for epidural catheters set forth by the American Society of Regional
Anesthesia and Pain Medicine. This was our only reference since specific guidelines do not exist for
neuromodulation therapies.
Objective
To research the incidence of PE/deep venous thrombosis (DVT) after dorsal column stimulator
implantation in the literature and evaluate risk of recurrent PE/DVT after cessation of anticoagulation
therapy. In addition, we hope to discuss any recommendations for discontinuation of anticoagulation
and surveillance prior to cessation of anticoagulation in a high risk patient population.
Methods
Pubmed literature search
Results/Discussion
Venous thromboembolism during dorsal column stimulator trial or after permanent implantation must
be an exceedingly rare complication, as there are no case reports in the literature describing such a
complication. Recurrent venous thromboembolism after cessation of anticoagulation, however, is
quite a common occurrence, with incidences as high as 50% in observational studies. It is common
practice now to continue anticoagulation indefinitely in patients who are high risk for recurrence and
low risk for bleeding complications. Prior to proceeding with discontinuation for any of our procedures,
we must have a conversation with regards to risk stratification with both the patient and their
hematologist/oncologist.
References
1. Agnelli G, Becattini C. Treatment of DVT: how long is enough and how do you predict recurrence. J
Thromb Thrombolysis. 2008 Feb;25(1):37-44. Epub 2007 Oct 1.
2. Heit JA. Predicting the risk of venous thromboembolism recurrence. Am J Hematol. 2012 May;87
Suppl 1:S63-7. Epub 2012 Feb 24.
3. Horlocker TT, et al. Regional anesthesia in the patient receiving antithrombotic or thrombolytic
therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines
(Third Edition). Reg Anesth Pain Med. 2010 Jan-Feb;35(1):64-101.
4. Konstantinides S, Goldhaber SZ. Pulmonary embolism: risk assessment and management. Eur
Heart J. 2012 Dec;33(24):3014-22. Epub 2012 Sep 7.
Funding
No grants or third-party research funding was utilized.