Download Acute pain relief at a teaching Hospital

Acute Pain Management
Dr Ashish Shetty
MBBS, MD(USA), FRCA, FFPMRCA
National Hospital for Neurology & Neurosurgery, UCLH
Honorary Consultant, Guys & St Thomas Hospital, London
Definition 1
Pain is an unpleasant sensory and emotional experience
associated with actual or potential tissue damage, or described
in terms of such damage.
IASP 1986
Acute Pain
1
Cause is known
2
Temporary (< 6 weeks)
3
Located in area of trauma
4
Resolves spontaneously
5
Trauma, Medical, Surgical
Clinical characteristics of
Acute Pain
 Sudden, sharp, intense, localised
 Usually self-limited
 Consequences
 Neuro-endocrine, Cardio-Respiratory, Gastrointestinal, Urinary
Musculoskeletal
Siddall PJ, et al. Neural Blockade in Clinical Anesthesia and Management of Pain; 1998:675–713.
Bonica JJ. The Management of Pain. Vol. 1; 1990.
24 yr old Jim
 Writhing in Pain
 Fracture of tibia
 Waiting to go to OR
So do post-surgery patients still
have pain?
 Main cause of concern of 57% of patients before surgery1
 Of 3000 surgical and medical patients discharged from
UK hospitals:
 87% had moderate-to-severe pain in hospital
 33% had pain that was present all or most of the time2
1. Warfield CA and Kahn CH: . Anaesthesiology 1995, 83:1090-1094. 2. Bruster S et al: National survey of hospital patients. British
Medical Journal 1994, 309:1542-1546.
How effective is postoperative pain
therapy?
1973–1999:
‘significant (P<0.000l) reduction in the incidence of
moderate-severe pain of 1.9 (1.1–2.7)% per year.’
Severe pain
Hypoventilation
% (95% CI)
Hypotension
% Mean (95% CI)
Intramuscular
analgesia
PCA
29.1
0.8 (0.2-2.5)
3.8 (1.9-7.5)
10.4
1.2 (0.7-1.9)
0.4 (0.1-1.9)
Epidural
analgesia
7.8
1.1 (0.6-1.9)
5.6 (3.0-10.2)
Dolin SJ, Cashman JN, Bland JM. BJA. 2002; 89(3);409-423
Acute pain pathways
Nociceptioninhibiting neurons
Pain
Perception
Noxious
stimulus
Ascending
input
Descending
modulation
Dorsal
horn
Peripheral
nociceptors
Activation of the peripheral
nervous system
Transmission of the pain
signal to the brain
Dorsal root
ganglion
Spinothalamic
tract
Peripheral
nerve
Transmission
Modulation
Input
Activation of CNS
at spinal cord
Primary sensory neurone termination in the dorsal horn
A
A
C
I
II
III
IV
To
dorsal
columns
V
VI
Mechanism
 Peripheral and central sensitisation
 Wind-up
 Recruitment of receptive fields
 Longterm potentiation
 Immediate early gene expression
Importance of Pain management
 Reduce the Risk of Adverse Outcomes
 Maintain the Patient’s Functional Ability, as well as
Psychological Well-being
 Enhance the Quality of Life
 Shortened Hospital Stay and Reduced Cost
 Patient comfort and satisfaction
1. Eisenach JC, et al. Anesthesiology. 1988;68:444–448. 2. Harrison DM, et al. Anesthesiology.
1988;68:454–457. 3. Miaskowski C, et al. Pain. 1999;80:23–29.
4. Finley RJ, et al. Pain. 1984;2:S397.
Pain Assessment Tools
Pain Assessment Tools
 In Adults: Self Report Measurement Scales, such as
Numerical Scales
 In Pediatric Patients:
 Physiologic and Behavioral Indicators of Pain ( Infants,
Toddlers, Nonverbal or Critically Ill Children)
 Face Scale (Age 3-10 yrs)
 Visual Analogue Scales (Age 10-18)
Management of Acute Pain
Pharmacologic
Interventional
Pharmacologic Management
 Alter Nerve Conduction (Local Anesthetics
 Modify Transmission in the Dorsal Horn (Opioids,
Antidepressants)
 CNS modulation
Routes of Administration
 PO
 PR
 IV
 IM
 Transdermal
 Transmucosal
 Epidural
 Intrathecal
Principles Of Pain Management
WHO
Analgesic ladder
Acute Pain Analgesic Staircase
 Stage 1: Immediately post-operative Strong
opioid eg morphine or epidural +/- non-opioid
analgesic
 Stage 2: Oral opioid for moderate to strong
pain +/- non-opioid analgesic( NSAID)
 Stage 3: Prior to discharge
opioid analgesic
Non-
What Endpoint Should Be
Achieved?
 Patient awake and not nauseated
 Ability to mobilise, cooperate with physiotherapy, eg
coughing, deep breathing
 VAS of below 30mm on a scale of 0-100mm seen as
adequate
New developments: Delivery technology
Non-opioid Analgesics
 Paracetamol: Acetaminophen
centrally acting 1g 6h or 1520mg/kg for children
 Diclofenac sodium: 50mg TDS
orally
 NSAIDs: Analgesic,
antipyretic,antiinflammato
ry
 Opioid sparing
 SE: Prostaglandin and
prostacyclin effect
 Ibuprofen, diclofenac,
naproxen, piroxicam
 COX 1 and COX 2
Non-Opioid Analgesics
 Acetaminophen
 NSAIDs ( Ibuprofen, Diclofenac)
 COX-2 inhibitors
 Lidocaine Patch
NSAIDs
 Relieve of Mild to Moderate Pain
 Complication:
 GI Discomfort
 GI Bleeding (Inhibition of COX-1)
 Nephrotoxicity
 Inhibition of Platelet Aggregation
 Osteogenesis
IV NSAID: Ketorolac
 Potent Analgesic
 Parenteral (IV or IM)
 15-30 mg Q 6hr
 Patients Older than 16 yrs
 Should not Exceed 5 days
Cox-2 Inhibitors
Drug
Dose
Celecoxib (Celebrex)
100-200mg PO Bid
Rofecoxib (Vioxx)
Valdecoxib (Bextra)
10-20mg PO Qd
Parecoxib
20-40mg IM
20-100mg IV
Compound Analgesics
 Co-Proxamol: Paracetamol 325mg,
Dextropropoxyphene 32.5mg
 Co-Dydramol: Paracetamol 500mg,
Dihydrocodeine 10mg
 Co-Codamol: Paracetamol 500mg,
Codeine phosphate 8mg
 Aspav:
Aspirin 500mg and opium
alkaloids
Weak opioids
Strong opioids
 Dihydrocodeine 30mg 4 hrly po

Morphine
 Tramadol weak iv,po agonist 50-

Fentanyl

Diamorphine

Pethidine: max 1.2g daily
100mg
 Buprenorphine 200-400mcg sl 4-6h
 Codeine phosphate 30-60mg 4h
Opioid Analgesics
 Bind to Opioid Receptors
 Morphine, Fentanyl, Codeine, Oxycodone,
Hydrocodone, Tramadol
 Multimodal analgesia enhance Opioid Analgesic
Effect
Opioid Analgesics
 Equianalgesic Conversion Charts are used when
Converting form one Opioid to Another, or Converting
from Parenteral to Oral Form
 Respiratory Monitors may be Used Depending on the
Patients Age, Co-existing Medical Problems, or Route
of Opioid Administered
Conversions : Morphine
Oral
Parenteral
300
100
Epidural
10
Intrathecal
1
Patient controlled analgesia
Patient Controlled Analgesia
 Small Doses of Analgesic Drug (Usually Opioids), are
Administered (IV) by Patient
 Allows Basal Infusion and Demand Boluses
 Over Dosage is Avoided
by Limiting the Amount
and Number of Boluses
in a Set Period of Time
Dose Regimens for PCA
Drug
Bolus Dose
(mg)
Lock-Out
(Minutes)
Morphine
1
5
Fentanyl
0.01-0.02
3
Patient Controlled Analgesia
 Advantages
Safe, effective, good analgesia, reduces delay, saves
nursing time, high patient satisfaction, few complications
 Disadvantages
Respiratory depression, nausea and vomiting,
programming errors, costs
PCA
120
100
80
intramuscular
PCA
60
40
20
0
0
1
2
3
4
5
6
7
8
Opioids
Drug
PO
mg
IV mg Starting Oral
Dose mg
Comments
Morphine
30
10
15-30
MS Contin, Release 8-12 hrs
MSIR for BTP
Methadone
20
10
5-10 Qd
Long Half-Life, 24-36 hrs
Accumulates on Days 2-3
Fentanyl
0.020.05
Fentanyl Patch, 12 hrs Delay
Onset and Offset
Opioids
Drug
PO mg
Comments
Precautions
Codeine
30-60
Combined With
Nonnarcotic Analgesics
Maximal Dose for
Acetaminophen
4gm/d
Oxycodone
5-10
Oxycodone 10-30mg Q 4h
Oxycontin 10mg Q 12h
Acetaminophen
or Aspirin toxicity
Tramodol
50-100 Q46hr
Central Acting, Affinity for
Mu Receptors
Maximal Dose
400 mg/d
Multimodal Analgesia
 Reduced doses of
each analgesic
Morphine
 Improved pain relief
Potentiation
 Synergistic /
additive effects
NSAIDs,
paracetamol,
nerve blocks
 Reduces severity of
side effects of each
drug
Kehlet H, Dahl JB. Anesth Analg. 1993;77:1048-1056.
Playford RJ, et al. Digestion. 1991;49:198-203.
Mean (SE) total pain relief for the
0.5- to 8-hour observation period
Diclofenac  Paracetamol 
Codeine
60
***
*p= 0.044; **p= 0.029; *** p= 0.002
*
50
**
40
30
20
10
0
D
P
P+C
D+P
D+P+C
D = 100 mg diclofenac alone;
P = 1 g paracetamol alone;
P+C = 1 g paracetamol plus 60 mg codeine;
D+P = single oral dose 100-mg enteric-coated diclofenac with 1 g paracetamol;
D+P+C = 100-mg enteric-coated diclofenac with 1 g paracetamol plus 60 mg codeine
Breivik et al, Clin Pharmacol Ther 1999;66:625-635
Adjuvant analgesics for opioid
sparing strategies
 Established
 NSAIDs and coxibs (safety and tolerability issues)
 Paracetamol
 Local anaesthetic techniques
 Recent additional choices
 Gabapentin
 Low dose ketamine
 Dexamethasone
Mr Jones will undergo a thoracotomy. What
would be your analgesia of choice?
Interventional Management
 Epidural Analgesia (Continuous Lumbar or Thoracic
Epidural Catheter Placement, PCEA)
 Spinal Analgesia
 Peripheral Nerve Block ( Single Shot or Continuous)
Epidural Space
 Surrounds the Dural
Sac
 Anteriorly: Post.
Long. Ligament
 Posteriorly:
Ligamentum Flavum
 Laterally: Pedicles and
Intervertebral Foramina
Anatomy of Epidural Space
 AP Dimension of the Epidural Space is Largest in the
Lumbar Region, 5-6 mm
 In Thoracic Region the AP Dimension Decreases but
the Space is More Continuous
MIDLINE SAGITTAL VIEW OF THE LUMBAR SPINE
Epidural Anesthesia
Acts the emerging nerve roots from Spinal Cord
“dermatomal “band” of Anesthesia
Level of Anesthesia Depends on :
 Volume of the Drug
 Level of Injection
Epidural Anesthesia
 Lumbar Epidural: Lower Extremity, Pelvic, and Lower
Abdominal Procedures
 Thoracic Epidural: Upper Abdomen and Thoracic
Procedures
 Caudal Injection: More Commonly Used for Pediatric
Patients (Genitourinary and Lower Abdominal
Procedures)
Advantages
 Superior Pain Relief with
 Lower Incidence of DVT and Pulmonary Emboli
 Decrease Blood Loss Intraoperatively
 More Rapid Recovery of Bowel Function
 Earlier Ambulation
 Better PFT
 Suppression of Neuroendocrine Stress Res
Grass JA. The Role of Epidural Anesthesia and Analgesia in Postoperative
Outcome. Anesthesiol Clin North America 01-JUN-2000; 18(2): 407-28
Contraindications
 Absolute
 Relative
 Patient Refusal
 Uncooperative
 Coagulopathy
 Increased ICP
 Skin Infection
Patient
 Pre-existing Neurologic
Disorder
 Anatomical Abnormalities
Drugs used in Epidural
 Local Anesthetics
Lidocaine: 1-2% , 45-90 min.
Bupivacaine: 0.25-0.5% , 90-120 min.
 Opioids : Diamorphine, Fentanyl
 Others :Clonidine, Ketamine etc.
Opioids in Epidural Space
Drug
Dosage
Onset
(min)
Duration
(hrs)
Morphine
2-3 mg
30-90
6-24
Fentanyl
50-100 mcg
5-15
2-4
Diamorphine
Advantages
Disadvantages
 Prolonged Single Dose
 Delayed Onset of
 Thoracic Analgesia with
 Unpredictable Duration
Analgesia
Lumbar Administration
 Minimal Dose Compared
with IV Administration
Analgesia
 Delayed Respiratory
Depression
Local Anaesthetic Techniques
 Local anaesthetics are either esters or amides
 Influence action potential along the nerve
 Local infiltration
 Nerve block/ Plexus block
 Caudal/ epidural/spinal analgesia
Epidural analgesia
Promises of epidural
analgesia
 Mortality
 Morbidity




Cardiovascular
Respiratory
Coagulation
Major infections
 Quality of pain relief
 Hospital costs
Problems
 Dural puncture
 Epidural haematoma
 Epidural abscess
 Failure of technique
 Training
 Resource restraint
Epidural complications
 Failure of Block (Patchy or Unilateral Block)
 Injury to Nerve
 Infection
 Epidural Hematoma or Abscess
 Dural Puncture (Total Spinal or PDPH)
Epidural complications
- Hypotension Secondary to Sympathetic Blockade
- Intravascular Injection (Local Anesthetic Toxicity)
- Respiratory Depression
- Sedation
- Bladder Distention
- Difficulty in Ambulation
Spinal Anesthesia
 Spinal Anesthesia : injecting small amount of local
anesthetic in the CSF
 Results in Rapid Onset of Block
 Rapid onset and requiring low dose of drugs
Spinal Anesthesia
 CSE, Used in Labor
 Preservative Free Morphine -Provides Pain Relief for
Abdominal, Pelvic, or Lower Extrimity Surgeries
 Complications Similar to Epidural Technique Except
for Higher Risk of PDPH
Caudal Block
 Single Injection or Continuous Infusion through a
Catheter
 Excellent Intraoperative and Postoperative Pain Control
 Easier to Perform in Children
 Analgesia that Last About 12 hrs if Bupivacaine Used
 Performed Following Induction of General Anesthesia
Indications for Caudal Block
 Surgeries in Sacral Segments, (Circumcision and other
Urologic Surgeries, Rectal Dilation)
 Combined with Light General Anesthesia Provides
Adequate Intraoperative Analgesia
Complications of Caudal Block
 Infection
 Dural Puncture and Spinal Anesthesia
 Intravascular Injection of Local Anesthetics
Peripheral Nerve Block
 Anesthetising the Nerve that is Innervating Surgical
or Painful Area
 Single Shot or Continuous Infusion through Catheter
 Upper Extrimity: Brachial Plexus, Median, Ulnar or
Radial Nerve
Peripheral Nerve Block
 Lower Extrimity: Sciatic, Femoral, Posterior Tibial,
Sural, Saphenous, Deep and Superficial Peroneal
Nerve
 Intercostal Nerve Block
 Surgical Wound Infiltration of Local Anesthetic
Julie 4yrs old is scheduled for
a fixation of her fractured
femur.
Pain Management in Children
 Consider Physiologic and Anatomic Differences
 Assessment and Communication barriers
 Pain and Anxiety Associated with Minor Procedures
or Unfamiliar Situations
Children
 Opioid sensitive
 PCA/NCA
 Simple analgesics very useful
 Regional analgesia
The Elderly patient
 Slow circulation time
 Associated diseases
 Respiratory recovery
important
 Early mobilisation
Elderly
 Patient Population Older than 65 yrs of Age is
Growing
 Age Related Physiologic Changes (Decreased
Muscle Strength): Decreased Cough
 Decreased Mental Status (Dementia): Decreased
Narcotic Dose
Mr Jones
Your consultant has decided to discontinue
the epidural analgesia. What are the
appropriate next steps?
Step down analgesia
 Aim: To discharge the patient on non-opioid analgesic
medication, often simple analgesics such as
paracetamol 1g QDS
 If the patient is discharged on strong opioids the GP is
informed and a reduction plan advised.
Chronic
pain after
surgery:
Phantom
limb pain
Summary
 Every patient has got individual needs.
 Pain is best treated in a multimodal fashion
 Balanced analgesia with opioids, reduced peripheral
stimulus (NSAID’s), interrupted pain pathways, eg
nerve block and alteration of emotional and behavioural
response
 Careful monitoring of cardiovascular and respiratory
functions in the postoperative patient
 Evidence that good pain relief will reduce the incidence
of ongoing pain
Multidisciplinary Approach
Surgeon
Pharmacist
Nurse
Acute Pain Team
Physiotherapist
Anaesthetist
Psychologist
My Philosophy
 No Pain….
My Philosophy
 No Pain….no Pain
Thank you