Download Obstetric Anaesthesia

Nonobstetric Surgery during
Pregnancy: Are we ready?
Berrin Günaydin, MD, PhD
Gazi University Faculty of Medicine
Department of Anesthesiology, Ankara, Turkey
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Multidisciplinary approach is a must for non-obstetric
surgery during pregnancy
Epidemiology
Each year over 75000 (87000) pregnant women in USA
undergo nonobstetric surgery
Semin Perinatol 2002
Chestnut’s 2009
Each year 5700-76000 (115000) pregnant women in EU
undergo nonobstetric surgery
Minerva Anestesiol 2007
Chestnut’s 2009
Epidemiology
Need for nonobstetric surgery 0.75%-2% (0.3%-2.2%)
J Clin Anesth 2006
Chestnut’s 2009
42% during the 1st trimester
35% during the 2nd trimester
23% during the 3rd trimester
These operations are either directly (such as; cerclage) or
indirectly (such as; appendectomy) related to pregnancy
Semin Perinatol 2002
FETAL CONCERNS
Risk of Teratogenicitiy
 Organogenesis is between 15-70 days after last
menstrual period
Manifestations of teratogenicity
 Death (abortion, fetal death and stillbirth in humans
and fetal resorption in animals)
 Structural abnormalities
 Growth restriction
 Functional deficiencies are usually associated with
exposure during late pregnancy or after birth (4th
intrauterine month to 2nd postnatal month)
IARS 2006
Risk of Teratogenicity
During maintaining normal maternal physiology
 local anesthetics
 volatile anesthetics
 induction agents (barbiturates, ketamine and propofol)
 muscle relaxants (wide margin of safety because of limited placental transfer)
 opioids are not teratogen in clinical concentrations
Evidence does not support association between diazepam & craniofacial defects
N2O is a weak teratogen in rodents by inhibiting methionine
synthase which alters DNA synthesis under certain conditions (at
50% concentrations for 24 hours)
No human data support increased risk for congenital anomalies
Minerva Anestesiol 2007
IARS 2006
J Clin Anesth 2006
FETAL CONCERNS
Preterm Labor
 It is unclear whether nonobstetric surgery, manipulation
of uterus or underlying condition is responsible from
increased incidence of preterm delivery and abortion
 22% of 778 patients who underwent appendectomy
between 24 to 36 weeks gestation delivered within first
week after surgery
Mazze &Kallen. A Swedish registry study of 778 cases. Obstet Gynecol 1991
 No increased risk of delivery one week after surgery
 2nd trimester procedures and those not involving uterine
manipulation carry the lowest risk of preterm labor
FETAL CONCERNS
Preterm Labor
 Evidence doesn’t suggest that any anesthetic agent or technique
influence the risk of preterm labor
 Prophylactic tocolytics may be considered but are associated
with side effects (it is unclear whether they affect the outcome
due to their limited efficacy for prevention of preterm labor)
 Selective administration at high risk patients (e.g. cervical
cerclage) or after 24 weeks gestation
 Additional surveillance is required for patients receiving potent
analgesics postoperatively
FETAL CONCERNS
Nondrug Factors
 Prolonged hypoxia and hypercarbia and severe hypoglycemia
 Maternal stress and anxiety
 Hyperthermia (teratogen in humans and animals)
 congenital CNS anomalies associated with maternal fever >38.90C during 1st
half of pregnancy
 Ionizing radiations (teratogen in humans and animals)
 No increase in anomalies/growth restriction from exposure <5-10rads
Behavioral Teratology
 Anesthetics act by potentiation of GABAA receptors or
antagonism of NMDA receptors induce widespread
neuronal apoptosis during period of synaptogenesis
 Result in hippocampal (cornu ammonis:CA & dentat
gyrus:DG) synaptic function deficit and persistent
memory/learning impairments
 The implications for human fetus or infants is unknown
Jevtovic-Todorvic et al. Early exposure to common anesthetic agents causes widespread
neurodegeneration in developing rat brain and persistent learning deficits. J Neurosci 2003
Role of ketamine on the apoptotic
effect of isoflurane in rats
Kartal S, Gunaydin B.
• Effects of ketamine (NMDA receptor antagonist) on the
isoflurane (GABA-A agonist) induced apoptotic
neurodegeneration was investigated
• Apoptotic neurodegeneration has been shown in
hypocampus (CA-1 and dentat gyrus) which was mediated
by caspase 3, 8 and 9
• Significantly more immunoreactive cells for caspase 3, 8
and 9 in group Iso+Ket were observed in the hypocampus
• Isoflurane induced apoptosis in rats increased by ketamine
Caspase 8
Caspase 8
Caspase 9
CA-1
Caspase 3
DG
Uteroplasental Perfusion & Fetal
Oxygenation
Causes of hypoxia
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Difficult intubation
Esophageal intubation
Pulmonary aspiration
High levels of regional block
Systemic local anesthetic toxicity
Airway compromise from trauma
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Causes of decreased
uteroplacental perfusion
Aortocaval compression
High spinal or epidural blockade
Hemorrhage
Hypovolemia
Hyperventilation
Deep levels of general anesthesia
High dose of ά adrenergic agents
Increased circulating catecholamines
Uterine hypertonus from ketamine
>2mg/kg in early pregnancy or toxic
doses of local anesthetics
TIMING OF SURGERY
 Elective surgery should not be performed during pregnancy
 Surgery should be avoided during the 1st trimester
 2nd trimester is the optimal time
 Urgent operations like abdominal emergencies, malignancies,
neurosurgical and cardiac conditions
 In serious maternal illness, primary goal is to preserve mother’s life
 Simultaneous C/S or prior to surgical procedure to avoid fetal risks
associated with special patient positioning (sitting or prone
position), prolonged anesthesia, major intraoperative blood loss,
maternal hyperventilation, deliberate hypotension or
cardiopulmonary bypass
FETAL MONITORING
 Continuous FHR monitoring (using transabdominal doppler)
feasible after 18 weeks of gestation
 FHR variability manifests after 25 to 27 weeks of gestation
 FHR patterns from drug effects (opiates, induction and
inhalation agents) should be distinguished from fetal hypoxia
 FHR monitoring allows optimization of intrauterine environment
 Nonreassuring pattern may indicate need to improve maternal
oxygenation, increase blood pressure, increase uterine
displacement, change site of surgical retraction or begin
tocolysis
FETAL MONITORING
According to ACOG opinion
 “The decision to use intraoperative FHR monitoring
should be individualized and each case warrants a
team approach for safety of woman and her baby”
 Plan should be in place for proceeding with urgent or
emergent cesarean delivery in the event of persistent
nonreassuaring FHR pattern
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Anesthetic Management
Preoperative care
Preanesthetic medications
Preoperative medication is traditionally withheld
•Sedatives are usually avoided (if necessary, 0.5-2 mg midazolam and/or 2550 µg fentanyl can be considered)
•Glycopyrolate (Anticholinergic agent of choice)
Does not readily cross the placenta
Prophylaxis
H2 receptor antagonists
Metoclopramide (10 mg IV)
Cholinergic agonist peripherally
Dopamin receptor antagonist centrally
Increases lower esophageal sphincter tone (antiemetic effect)
Reduces gastric volume by increasing gastric peristalsis
Crosses placenta but no significant effect on the fetus
Clear nonparticulate antacids
Sodium bicitra ( oral 30 mL)
Kuczkowski KM. Arch Gynecol Obstet 2007
Reduces gastric acidity
Anesthetic Management
Prevention of aortocaval compression
Positioning must ensure 15⁰ left lateral tilt (since changes in
maternal position can have profound hemodynamic effects, either
Trendelenburg or reverse Trendelenburg’s positions should be
carried out slowly)
J Clin Anesth 2006
Maternal and fetal monitoring
ECG, heart rate, SpO2 and ETCO2
Blood pressure (noninvasive or invasive)
Peripheral nerve stimulator
Temperature
FHR and uterine activity
Chestnut’sObstetric Anesthesia Principles and Practice2009
Anesthetic
Technique
Both regional and general anesthesia techniques have been
successfully used for nonobstetric surgery
Regional Anesthesia
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Decreased protein binding due to
low albumin
Increased sensitivity to peripheral
neural blockade
More extensive blockade with
epidural and spinal anesthesia
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General Anesthesia
Rapid sequence IV induction
Denitrogenation (100% O2 for 5 min)
Effective cricoid pressure
Endotracheal intubation is mandatory
In case of failed intubation, LMA can
be used in the reverse Trendelenburg’s
position for brief periods
Alveolar hyperventilation, reduction
of FRC and 30% reduction of MAC
Decreased thiopental requirements
J Clin Anesth 2006
EFFECTS OF ANESTHETIC
AGENTS ON THE FETUS
Inhalation
agents
Intravenous
induction
agents
Neuromuscular
blocking agents
Decreased plasma
 N2O may impair DNA Thiopental history of safe use cholinesterase levels by 25%
Prolonged neuromuscular
synthesis and inhibit  (propofol added to list later) blockade with Sch is
cell division
 Benzodiazepines are avoided uncommon due to increased Vd
 No evidence suggests during organogenesis
reproductive toxicity  Narcotics may be related to
with sevoflurane or
intrauterine fetal asphyxia
desflurane in clinical  Morphine and fentanyl have
concentrations
also history of safe use
Chestnut’sObstetric Anesthesia Principles and Practice2009
Vecuronium when Sch is
contraindicated (prolonged duration)
Rocuronium alternative to SCh
in high doses (longer duration of action)
Cis-atracurium less desirable
for RSI (shorter duration due to
Hoffman’s elimination in vivo)
Reversal Agents
 Anticholinesterases have a theoretical concern because of
increased uterine tone that may precipitate preterm labor
 Transplacental transfer of anticholinesterase is predicted as
limited due to molecular size & structure of neostigmine but
it can have significant fetal effecs
 Although atropine which readily crosses placenta may cause
fetal tachycardia and loss FHR variability, it may be
preferable to counteract fetal effects of neostigmine instead
of glycopyrolate
IARS 2006
Postoperative Care
 FHR and uterine activity should be monitored during
recovery from anesthesia
 Satisfactory maternal analgesia can be achieved with
systemic narcotic PCA or PCEA when available
 Regional analgesia provides better pain relief and less
effect on FHR variability
 Use of NSAI drugs is avoided (because of potential premature
closure of DA and development of oligohydramnios)
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Specific Situations
Laparoscopy
Cardiac surgery requiring CPB
Neurosurgery
Malignancy- metastatic breast cancer requiring
surgery
Type of surgery
 Laparoscopic surgery
The most common abdominal procedures
 Appendectomy 1/1500-2000 pregnanccy
 Cholecystectomy 1-8/10000 pregnancy
 Cardiac surgery requiring bypass
 Neurosurgery
J Clin Anesth 2006
SAGES Committee Opinion
I. Obtain an obstetric consult preoperatively
II. Delay elective cases until 2nd trimester
III. Use lower ext pneumatic compression
devices (pregnancy and pneumoperitoneum
may induce a hypercoagulable state)
IV. Follow maternal and fetal physiologic
status intraoperatively (maternal ETCO2)
Society of American Gastrointestinal Endoscopic Surgeons (SAGES)
Guidelines for laparoscopic surgery during pregnancy
SAGES Committee Opinion
V.
Protect uterus with lead shield for
intraoperative cholangiography
VI. Use open technique to gain
pneumoperitoneum
VII. Tilt table left side down to move gravid
uterus off vena cava
VIII.Minimize pneumoperitoneum to 8 to 12 mm
Hg
Society of American Gastrointestinal Endoscopic Surgeons (SAGES)
Guidelines for laparoscopic surgery during pregnancy
Appendectomy
 The most common nonobstetric surgical
emergency during pregnancy
 Appears to occur more frequently in the 2nd and
3rd trimesters
 The mortality of appendicitis complicating
pregnancy is the mortality of delay
Laparoscopic Surgery During Pregnancy
Adding pneumoperitoneum to an enlarged uterus
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Limits diaphragm expansion
Increases peak airway pressure
Decreases FRC
Decreases thoracic cavity compliance
Increases ventilation-perfusion mismatching
Laparoscopic Surgery During Pregnancy
 CO2 pneumoperitoneum
hypercapnia and hypoxemia
 Hyperventilation
reduce uteroplacental blood flow
 Reduced venous return and cardiac index
significant hypotension
 Intermittent pneumatic compression devices
and thrombophylaxis are important
Cardiac surgery during pregnancy
Incidence of heart disease in pregnancy 1%-4%
Decompensation may peak at 28 to 30 weeks
Maternal mortality rate 20% to 35%
Cardiac surgery indications are few
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Severe valve disease
Malfunction of prosthetic valve
Major vessel disease
Traumatic aortic rupture
Pulmonary embolism
Heart tumor
Patent foramen ovale
Clin Obstet Gynecol 2009
Cardiac surgery during pregnancy
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Fetal bradycardia is common during bypass
Hypothermia is associated with uterine irritability
Duration of CPB does not affect fetal outcome
Maternal temperature above 29.5⁰C is associated with
better fetal survival
 Highest maternal mortality occurs if surgery is performed
at delivery or immediately postpartum
Clin Obstet Gynecol 2009
CPB
 Moderate hypothermia during bypass
 Persistent fetal bradycardia
 Warm cardiopulmonary bypass will improve
 Increase pump flow, if FHR<80 bpm
 Ensure adequate uteroplacental perfusion
 Maintain pump flow 30-50% greater than usual
 Maintain perfusion pressure at or above 60 mmHg
 Avoid aortocaval compression
 Optimize acid-base status, oxygenation, and ventilation
Kuczkowski KM, CME Rev 2003
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24 year old parturient at 32 weeks’ gestation
158 cm, 60 kg
Severe mitral stenosis
Open mitral commissurotomy
General anesthesia
– Induction with propofol, fentanyl, pancuronium
– Maintenance by TIVA
• Continuous FHR monitorization
• CPB under mild hypothermia (30-32ºC)
• 10 min after aortic cross clamping, progressive
decelerations in FHR tracing followed by asystole
• After rewarming, heart was defibrillated and CPB was
discontinued
• Then, protamine was administered
• Since no FHR, pregnancy termination was considered by
obstetricians
• However, 2 hours after patient was transferred to the ICU,
normal and rhythmic FHR returned
• Parturient vaginally delivered at term
• Authors conclude that loss of fetal heart sounds during
CPB should not always indicate fetal death
Neurosurgery During Pregnancy
Neurosurgical Approach
 Controlled hypotension (Volatile anesthetic, nitroglycerin or nitroprusside)
 Reduction in SBP of 25-30% or MBP< 70mmHg causes
reduction in uteroplacental blood flow
Nitroprusside
 crosses placenta resulting in fetal hypotension
 converted to cyanide (may cause significant toxicity & fetal death)
 Discontinue if
Infusion rate> 0.5 mg/kg/hour
Maternal metabolic acidosis
Resistance to the agent
 Hypothermia - Fetal bradycardia
 Hyperventilation Decreased placental O2 transfer & umbilical vessel
vasoconstriction
 Diuresis - Significant negative fluid shift for fetus
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Case 2: Sequential operation (C/S followed anterior corpectomy &
posterior spinal decompression) at 34 weeks’ of gestation
38 yr old parturient who underwent radical mastectomy and
chemotherapy 9 years ago due to invasive ductal Ca stage II/III
Admitted with paraplegia due to spine metastasis at 31 weeks
1850 g healthy baby was delivered by C/S under general anesthesia
Rapid sequence IV induction with propofol and Sch (7.0 mm cuffed tube)
After delivery, anesthesia was maintained in 0.7 MAC isoflurane
and remifentanil infusion
Clinical Suggestions
All women between 12 to 50 years should have the
last menstrual period documented
If pregnancy is diagnosed, surgery is postponed
until 2nd trimester if possible
Elective surgery is postponed until after delivery, if
not possible then 1st trimester should be avoided
 1st trimester: theoretical risk of teratogenicity is increased
 2nd trimester: optimal time to perform surgery
 3rd trimester: preterm labor and maternal risk is high
J Clin Anesth 2006
Objectives for anesthetic management
during non-obstetric surgery
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Provide maternal safety
Avoid using teratogenic drugs
Maintain uteroplasental perfusion by
preventing intrauterine fetal asphysia
Avoid preterm labor
Potential teratogens during pregnancy
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Angiotensin converting enzim inhibitors
Alkol
Androjenler
Antitiroid drugs
Carbamazepin
Chemotherapeutic drugs
Cocaine
Coumadin
Dietilstilbesterol
Lead
Lithium
Mercury
Phenytoin
Radiation (>0.5Gy)
Streptomycine/Canamycine
Tetracycline
Trimetadion
Valproic acite
Vitamine A
ACOG Committee Opinion No: 474
Nonobstetric surgery during pregnancy
ACOG Committee on Obstetric Practice
Obstet Gynecol. 2011 Feb;117(2 Pt 1):420-1
The American College of Obstetricians and Gynecologists'
Committee on Obstetric Practice acknowledges that the issue
of nonobstetric surgery during pregnancy is an important
concern for physicians who care for women. It is important
for a physician to obtain an obstetric consultation before
performing nonobstetric surgery and some invasive
procedures (eg, cardiac catheterization or colonoscopy)
because obstetricians are uniquely qualified to discuss aspects
of maternal physiology and anatomy that may affect
intraoperative maternal-fetal well-being. Ultimately, each
case warrants a team approach (anesthesia and obstetric care
providers, surgeons, pediatricians, and nurses) for optimal
safety of the woman and the fetus
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Arch Gynecol Obstet. 2007 Sep;276(3):201-9. Epub 2007 Mar 13.
Laparoscopic procedures during pregnancy and the risks of anesthesia: what does an
obstetrician need to know?
Kuczkowski KM.
Source
Department of Anesthesiology, University of California San Diego (UCSD) Medical
Center, 200 W. Arbor Drive, San Diego, CA 92103-8770, USA. [email protected]
Abstract
BACKGROUND:
Nonobstetric surgery may be necessary during any stage of gestation.
METHODS:
The purpose of this article is to review the current recommendations (using Medline search
for the relevant publications) for the perioperative anesthetic management of pregnant
women undergoing laparoscopy for indications unrelated to pregnancy.
RESULTS:
The current estimates of the incidence of nonobstetric surgery in pregnancy range from 1%
to 2%. Laparoscopy is the most common surgical procedure performed in the first trimester
of pregnancy, whereas appendectomy is the most common procedure performed during the
remainder of pregnancy.
CONCLUSIONS:
In the past pregnancy was considered as an absolute contraindication to laparoscopy.
However, recent years have brought an extensive experience with this technique during
gestation.
ACOG Committee
on Obstetric Practice acknowledges that the
issue of nonobstetric surgery and anesthesia
in pregnancy is an important concern for
physicians who care for women. However,
there are no data to allow us to make
specific recommendations.
Number 284, August 2003
Thank you -Teşekkürler...
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