Principles of Surgery Principles of Surgery PERI-OPERATIVE PERI-OPERATIVE

ANALGESIAANALGESIA

Joseph Kay, MD FRCPCSunnybrook & Women’s College HSC

Assistant Professor, University of Toronto

Why should we treat Why should we treat peri-operative pain?peri-operative pain?

pain and suffering complications likelihood of chronic pain patient satisfaction speed of recovery LOS cost productivity and quality of life

Adverse effects of poor pain Adverse effects of poor pain managementmanagement

CardiovascularRespiratoryGastrointestinal\GenitourinaryNeuroendocrine\MetabolicMusculoskeletalImmunologicalPsychological

Current pain managementCurrent pain management

Pain can virtually be eliminated with minimal side effects

BUT

70% inpatients still have moderate or severe pain 40% outpatients have significant pain in 1st 24 h

WARFIELD Anesthesiol 1995 83:1090 BEAUREGARD Can J Anesth 1998 45:304

Barriers to effective pain Barriers to effective pain management Imanagement I

ANESTHESIOLOGIST

Inadequate pain educationUnderestimation analgesic requirementsFailure to recognize patient variabilityInadequate use local\regional techniquesComplications from side effects

Barriers to effective pain Barriers to effective pain management IImanagement II

PATIENT

Expectation of severe painInadequate pain educationAnalgesic side effectsFear of addiction

Barriers to effective pain Barriers to effective pain management IIImanagement III

NURSE

Expectation of severe painInadequate pain educationFear of causing analgesic side effects e.g

respiratory depression, addictionInsufficient time for assessment/ treatment

Barriers to effective pain Barriers to effective pain management IVmanagement IV

SURGEON

Belief that pain is ‘normal’ and not harmfulConcern that pain may mask injuryInadequate pain education‘Don’t ask don’t tell’Complications from side effects\addiction

Barriers to effective pain Barriers to effective pain management Vmanagement V

HOSPITAL

Inadequate funding & resources with pain as low priority

Inadequate commitment Lack of accountability

Traditional opioid analgesiaTraditional opioid analgesia

Parenteral prn

Traditional opioid analgesiaTraditional opioid analgesia

Sedation Respiratory depression Nausea & Vomiting Urinary retention Ileus Constipation Pruritus

Multimodal AnalgesiaMultimodal Analgesia

Using more than one drug, acting at a different place or with a different mechanism, each with a lower dose than if used alone, thus providing better analgesia with less side effects.

Multimodal AnalgesiaMultimodal Analgesia

Opioid NSAID (COXIB) Acetaminophen Local anesthetic block Other adjuncts

Multimodal AnalgesiaMultimodal Analgesia

Multimodal AnalgesiaMultimodal Analgesia

Better analgesia Less side effects Can decrease hospital stay May improve surgical outcome May decrease chronic pain

KEHLET Br J Surg 1999 86:227 CAPDEVILLA Anesthesiol 1999 91:8

REUBEN Anesthesiol 2001 95:390

Multimodal AnalgesiaMultimodal AnalgesiaOpioidsOpioids

Systemic - oral/parenteral/transdermalNeuraxial - spinal/epiduralPeripheral - intra-articular, periosteal

Multimodal AnalgesiaMultimodal AnalgesiaOpioidsOpioids

Sites of action

Central: dorsal horn spinal cord Peripheral: synovium

periosteum

Multimodal AnalgesiaMultimodal AnalgesiaOpioidsOpioids

Systemic

Oral - contin + b/t Parenteral - iv PCA

sc infusion + b/t

Multimodal AnalgesiaMultimodal AnalgesiaOpioidsOpioids

Neuraxial

Spinal - single shot Epidural - continuous infusion

(+local anesthetic)

Multimodal AnalgesiaMultimodal AnalgesiaOpioidsOpioids

Peripheral

Intra-articular Iliac crest bone graft

OpioidOpioidIntraoperative vs PostoperativeIntraoperative vs Postoperative

THA 40 pts Intra-operative group:

achieved VAS<3 42 vs 76 min morphine PACU 7 vs 15 mg respiratory depression

PICO Can J Anesth 2000 47:309

OpioidOpioidOral Controlled ReleaseOral Controlled Release

Oxycontin

TKA 59 pts 29 oxycontin vs 30 placebo Oxycodone q4h prn Oxycontin group: pain LOS 2.3 days ROM

CHEVILLE J Bone Jt Surg Am 2001 83A6:915

OpioidOpioidIliac Crest InfiltrationIliac Crest Infiltration

Spine fusion 60 pts

Group I: saline into donor site

Group II: 5 mg i.m morphine

Group III: 5 mg morphine into donor site

OpioidOpioidIliac Crest InfiltrationIliac Crest Infiltration

Gp III 50% less morphine 24h lower pain scores > 2h pain at 1 yr 5% vs 33%

REUBEN Anesthesiol 2001 95:390

Multimodal AnalgesiaMultimodal Analgesia NSAID / COXIBSNSAID / COXIBS

potent analgesics for mild-moderate painadjunct to opioid for moderate-severe pain VAS 2/10 opioid consumption 30-50% opioid related side effects

NSAIDNSAID

Spinal fusion 70 pts Morphine PCA ketorolac 0-30 mg iv q6h

Ketorolac 7.5-30 mg: morphine use pain VAS sedation nausea

REUBEN Anesth Analg 1998 87:98

NSAIDNSAIDside effectsside effects

GI ulceration mild platelet dysfunctioninhibition bone fusionmild Na+ retention / hypertension renal function in low flow states

NSAIDNSAIDside effectsside effects

CAN WE MAKE A BETTER NSAID?

Keep analgesic potencyReduce side effects

NSAIDNSAIDmechanism of actionmechanism of action

inhibits cyclo-oxygenases (COX-1&2) which convert arachidonic acid to prostaglandins (PG)

PGE2 to sensitize nociceptors

PGE2, PGI2, TXA2 for homeostasis

COXCOX2 isoforms2 isoforms

COX-1 constitutive – everywhere ‘housekeeping’

PGE2, PGI2, TXA2

COX-2 constitutive in kidney, CNS induced by trauma / pain

main source PGE2 for sens.

PGEPGE22

productionproduction

EP

receptor

BK

receptor

Tissue Injury

IL-1

Peripheral induction of COX-2

Central induction of COX-2

PGEPGE22 sensitizationsensitization

EP

receptor

BradykininBK

receptor

PGE2

Tissue Injury

PGE2

YESYES

Can we make a selective COX-2 inhibitor with excellent analgesia and less side effects than a conventional NSAID?

COX-2 COX-1

Active site

Arachidonicacid

Active site

Arachidonicacid

NSAIDNSAID

COX-2 COX-1

Active site

COX-2 Inhibitor

Active site

Arachidonicacid

COX-2 Inhibitor

PGE2 PGI2 TXA2

Arachidonicacid

COX-2 inhibitorsCOX-2 inhibitors

CelecoxibRofecoxibValdecoxib

COXIBCOXIBanalgesic potencyanalgesic potency

similar to or more potent than NSAIDsvaldecoxib 40 mg = ketorolac 30 mg = 2 percocets! 24h duration

DANIELS J Am Dent Assoc 2002 133:611 MEHLISCH J Oral Maxillofac Surg 2003

61:1030

COXIBCOXIBpre-emptive effectpre-emptive effect

rofecoxib 50 mg given 1 h pre-incision vs post pain opioid consumption

prevents PGE2 sensitization from up-regulated COX-2

REUBEN Anesth Analg 2002 94:55

COXIBCOXIBside effects: GIside effects: GI

incidence ulcers or bleeding compared to conventional NSAIDs

BOMBARDIER NEJM 2000 343:1520

COXIBCOXIBside effects: renal functionside effects: renal function

COX-2 constitutive in kidney same effect as conventional NSAID mild Na+ retention, blood pressure renal blood flow in hypovolemia or CO

Avoid in hypovolemia, CHF, renal dysfunction, uncontrolled BP ,DM

BRATER J Pain Symptom Management 2002 23:S15

COXIBCOXIBside effects: bone fusionside effects: bone fusion

conventional NSAIDs inhibit bone growth & fusion

coxibs do not appear to clinically affect bone fusion

rofecoxib/celecoxib vs control vs ketorolac in spinal fusion patients

9/132 vs 6/90 vs 23/120

GLASSMAN Spine 1998 23:834 REUBEN ASRA Annual mtg 2002 Abstract PD-16 LEWIS Proc NA Spine mtg 2000 64

COXIBCOXIBside effects:allergyside effects:allergy

Can use in asthmaticsMay use rofecoxib with caution in ASA

allergyAvoid celecoxib/valdecoxib with sulfa allergy

GLASSER Pharmacotherapy 2003 23:551 STEVENSON J Allergy Clin Immun 2001 108 :47

COXIBCOXIBside effects: platelet functionside effects: platelet function

NO effect on plateletsNO effect on bleedingPatients on warfarin may have INR (need to adjust dose for cel/rof)

LEESE Am J Emerg Med 2002 20:275 HOMONCIK Clin Exp Rheumatol 2003 21 :229

SummarySummaryCOXIBS compared to NSAIDsCOXIBS compared to NSAIDs

more potent analgesic avoid opioidlonger duration once a daypre-emptive effect use pre-op no effect on platelets use pre-op less or no GI S/E use in riskno effect on bone fusion use in ortho

Multimodal Analgesia Multimodal Analgesia AcetaminophenAcetaminophen

Central COX 3 inhibitor opioid use by 30% opioid related side effects

SHUG Anesth Analg 1998

Multimodal Analgesia Multimodal Analgesia AcetaminophenAcetaminophen

Avoid with:

hepatic insufficiency alcoholism malnutrition P450 inducers

Multimodal Analgesia Multimodal Analgesia Acetaminophen + NSAIDAcetaminophen + NSAID

usual adjunct for PCA opioidcombination better than either aloneVAS rest & dynamic

FLETCHER Can J Anesth 1997 44:479

Multimodal AnalgesiaMultimodal Analgesia Local anestheticLocal anesthetic

InfiltrationIntraperitonealNerve blockNeuraxial

Local anestheticLocal anesthetic

Movement assoc pain reduces function

Local anesthetic blocks A & c fibres

Incisional local infiltrationIncisional local infiltration

Lap chole 157 pts periportal & intraperitoneal bupivacaine pre-incision or at end

pain first three hours with pre-incisional periportal bupivacaine (+/- intraperitoneal)

LEE Can J Anesth 2001 48:545

Peritoneal local infiltrationPeritoneal local infiltration

Appendectomy Peritoneal infiltration 0.5% bupivacaine

pain scores analgesic consumption

COLBERT Can J Anesth 1998 45:734

Local infiltrationLocal infiltration

Bupivacaine is

BACTERICIDAL

AYDIN Eur J Anesth 2001 18:687

Nerve BlockNerve BlockSingle shotSingle shot

ankle block interscalene

0.5% bupivacaine 6-24h postop analgesia

Nerve BlockNerve BlockContinuousContinuous

Continuous Femoral Nerve Blk

post total knee arthroplasty

compared to

PCA or epidural

Nerve BlockNerve BlockContinuous femoralContinuous femoral

Better analgesia Less morphine use Less opioid related side effects Better ambulation & hemodynamic stability

CAPDEVILLA Anesthesiol 1999 91:8 SINGELYN Anesth Analg 1998 87:88CHELLY J Arthroplasty 2001 16:436

Nerve BlockNerve BlockContinuous femoralContinuous femoral

Better surgical outcome

Less perioperative bleeding Increased flexion with CPM Earlier hospital discharge Less time in rehabilitation

CAPDEVILLA Anesthesiol 1999 91:8 SINGELYN Anesth Analg 1998 87:88CHELLY J Arthroplasty 2001 16:436

Nerve BlockNerve BlockSingle shot femoralSingle shot femoral

40 ml 0.25% bupivacaine vs saline post TKA

pain VAS 1-2 50% morphine use 50% morphine related side effects Better ambulation LOS 3 vs 4 days

WANG Reg Anesth Pain Med 2002 27:139

Nerve BlockNerve BlockContinuous interscalene /poplitealContinuous interscalene /popliteal

Disposable pumps Major shoulder /leg

surgery can be done as an outpatient

$

Nerve BlockNerve BlockContinuous popliteal nerve block at homeContinuous popliteal nerve block at home

30 pts randomized to local anesthetic or saline

Rescue oral opioids VRS 0 vs 4/10 Sleep disturbances 10x

less O opioid pills vs 8

ILFIELD Anesthesiology 2002 97:208

Epidural AnalgesiaEpidural Analgesia

Epidural AnalgesiaEpidural Analgesia

LOCAL /OPIOID

superior analgesia better

cardiopulmonary function

earlier return bowel function

Epidural AnalgesiaEpidural Analgesia

LOCAL /OPIOID

better ambulation decreased hospital stay safe to use on wards

Epidural AnalgesiaEpidural Analgesia

Sigmoidectomy

Early ambulation & feeding2 day median hospital stay

KEHLET Br J Surg 1999 86:227

SummarySummary

Pre-op Coxib Local infiltration / blockAcetaminophen / Coxib post-opControlled release opioid Thoracic epidural for major abdominal &

thoracic surgeryContinuous nerve blocks for extremity

surgery