pranav post operative pain management
TRANSCRIPT
kEY cONCEPTS iN pOST-OPERATIVE pAIN mANAGEMENT
Dr Pranav BansalAssociate ProfessorDept of Anaesthesiology
BPS Govt. Medical College for Women, Khanpur Kalan, Sonepat
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.
IASP Pain Definition (1994, 2008)
According to Katz and Melzack, pain is a personal and subjective experience that can only be felt by the sufferer.
It is easier to find men who will volunteer to die, than to find those who are willing to endure pain with patience. Julius Caesar
What is Pain?
ACUTE PAINCUTANEOUS PAINDEEP SOMATIC PAINVISCERAL PAINCHRONIC PAINREFERRED PAINNEUROPATHIC PAINPHANTOM PAIN
TYPES OF PAIN
Pain Assessment Visual Analogue Scale
Why Treat Pain?
Basic human right!Moral responsiblity ↓ suffering and post operative complications↓ likelihood of chronic pain development↑ patient satisfaction
Consequences of poorly managed acute post-operative pain
The Patient may suffer from:CVS: Tachycardias, dysrhythmias, IschaemiaResp: atelectasis, pneumoniaGI: ileus, anastamosis failureHypercoagulable state: DVTImpaired immunological state:
Delayed wound healing
Psychological:Anxiety, Depression, Fatigue, Sleep
DeprivationChronic Post-surgery Pain
ForThe Healthcare professional:Low MoraleComplaints to/towards/against InstituteLitigation
Consequences of poorly managed acute post-operative pain
CAUSES OF VARIATION IN ANALGESIC REQUIREMENTS
Site and type of surgeryAge, gender Psychological factors Pharmacokinetic variabilityPharmacodynamic variability
Surgical pain
Mild Intensity PainHerniotomyVaricose veinGynecological laparotomy
Moderate Intensity PainHip replacementHysterectomyMaxillofacial
Severe Intensity PainThoracotomyMajor abdominal surgeryKnee surgery
Paracetamol /NSIADs / weak opiodsWound infiltrationRegional block analgesiaAdd weak opioid or rescue analgesia
Paracetamol /NSIADs +Wound infiltrationPeripheral nerve blockSystemic opioidsPCA
Paracetamol /NSIADs+ Wound infiltration Epidural anesthesia Systemic opioidsPCA
Treatment modality
Surgical procedure
WHO Analgesic Ladder
WHO analgesic guidelinesOral medications whenever possibleDose “by the clock” – but always have “as
needed”medications for breakthrough painTitrate the doseUse appropriate dosing intervalsBe aware of relative potenciesTreat side effects
Multimodal (Balanced) AnalgesiaUsing more than one drug for pain control
Different drugs with different mechanisms/ sites of action along pain pathway
Each with a lower dose than if used aloneCan provide additive or synergistic effectsProvides better analgesia with less side effects
(mainly opiate related S/E)
Always consider multimodal analgesia when treating pain
The administration of analgesic agents prior to an injury in order to prevent development of central nervous system hyperexcitability or sensitization
Preemptive analgesia
Methods to Treat Postoperative PainPharmacologic (Medications (PO/IV/PR)
Acetaminophen (Paracetamol)NSAIDsOpioidsAlpha-2 agonists
ProceduresRegional Anesthesia LA infiltration at incision site
Nonpharmacologic ApproachesMusic and AudioanalgesiaTranscutaneous electrical nerve stimulation (TENS)
Site of Action of Analgesics
Acetaminophen (Paracetamol)First-line treatment if no contraindicationMechanism: thought to inhibit prostaglandin
synthesis in CNS → analgesia, antipyreticTypical dose: 650 to 1000 mg PO every 6HMax dose: 4 g / 24 hrs from all sourcesWarning: ↓ dose / avoid in those with liver
damage
NSAIDsFirst-line treatmentMechanism
Block cyclooxygenase (COX) enzyme → ↓ prostaglandin synthesis
COX-2 → Prostaglandins → pain, inflammation, feverCOX-1 → Prostaglandins → gastric protection,
hemostasis
No physical dependenceNo toleranceCeiling effect
NSAIDDrug Dosage Maximum daily
doseDiclofenacPiroxicamIbuprofen Ketorolac
Ketoprofen
50 mg PO bd/tds20 mg OD200-800 mg q 6 hr.3 x 30-40 mg/day (only IV form)4 x 50 mg/day
200 mg40 mg
3200 mg
Cox-2 inhibitorCelecoxib Parecoxib
100-200 mg PO bid40 mg followed by 1-2 x 40 mg/day (IV form)
400 mg
NSAIDsWarnings: ↓dose / avoid if
GI ulceration Bleeding disorders / CoagulopathyRenal dysfunctionHigh cardiac risk – COXII inhibitorsAsthmaAllergy
TramadolMultiple mechanism
Weak µ-receptor agonistInhibit serotonin & NE reuptake
Application : Mild to Moderate Post-op pain
Dose : 50-100 mg PO q 4-6 hr.Max. 400 mg/dSide effect: Nausea and Vomitting
OpioidsEssential element of pain managementMechanism
Action on opioid receptorLocated mainly in spinal cord & brain stem, some
in peripheral tissue
Opioids receptorsReceptorsMu (μ or OP3)
μ1μ2
Kappa (κ or OP2)Delta (δ orOP1)Sigma(σ)
Clinical effect
Analgesia, sedation, euphoriaResp. depression, physical dependenceSpinal analgesia, resp. depressionAnalgesia, resp. depressionDysphoria, hallucination, tachycardiahypertension
Opioids
1.Agonists : stimulate receptor : no ceiling effect ( no limit mg/kg)
: moderate to severe pain : Codiene, morphine, pethidine,
fentanyl, methadone
Opioids2. Partial agonists
: ceiling effects eg. Buprenorphine
Opioids3. Agonists-antagonists
: agonist-κ or σ receptor but antagonist to μ receptor
: can used in mild to moderate pain : ceiling effects
: precipitate withdrawal in opioids dependent
E.g: Pentazocine, Nalbuphine, Nalorphine
Side Effects include:Nausea / Vomiting, Pruritus, Constipation, Urinary Retention,
Ileus, Sedation, Respiratory Depression, Tolerance
Opioid OverdoseManifests as Somnilence, respiratory depression, bradycardia, miosis.
Management: Stimulate patient Attach Monitors/ IV Lines and record VitalsAirway, Breathing, Circulation Shift to ICU
Opioids
Opioid OverdoseOpioid Reversal
Naloxone - Pure antagonist at all the Opioid receptors
Reverses effects of opioid overdose (for 30-45min)0.4mg ampuoleDilute: 1mL Naloxone + 9mL
Saline = 0.04 mg/mL conc.Give 0.04 to 0.08 mg (1 to 2
mL) IV every 3-5 minutes till condition improves
Local Anaesthetics
LA bind sodium channels preventing propagation of action potentials along nerves
Wide variety of LA with different characteristics:Lidocaine (Lox) – fast onset, short duration of
actionBupivacaine (Sensorcaine) – slow onset, longer
duration Ropivacaine: longer duration, less cardiotoxic
AgentsLidocaine-infiltration-epidural-plexus or nerveBupivacaine-infiltrate-epidural-plexus or nerve
% solution
0.5-11-2
0.75-1.5
0.125-0.25
0.25-0.750.25-0.5
Duration(h)
1-21-21-3
1.5-61.5-68-24+
Max dose
7mg/kg
3 mg/kg
Local Anaesthetics
Potential side effects of Local anesthetics- Residual motor weakness- Peripheral nerve irritation- Cardiac arrhythmias- Allergic reactions-Sympathomimetic effects (due to vasoconstrictors)
Regional Anesthesia techniques in PostOperative Pain Management
Peripheral nerve blocksIlioinguinal/hypogastric : herniorrhaphyBrachial plexus : arm, handThoracic: Intrapleural Regional Anaesthesia (IPRA), Paravertebral, intercostal blocksPenile : circumcisionIntercostal/paravertebral : breastLower Limb: Femoral, sciatic, popliteal, ankleParacervical : F&C, D&C, cone biopsyAbdomen:TAP blocks
Epidural AnalgesiaEpidural Catheter placed in lumbar or thoracic
segments. LA+ Opioids given via bolus dosing, Infusion pump or
Patient Controlled Analgesia pump•Superior analgesia compared to Intravenous drugs in thoracic/ abdominal procedures•Reduced systemic opiate requirements•Improves GI blood supply
Patient Controlled Analgesia Pump
Regime for using IV Morphine in PCA pump
Regime for using Epidural Opioids with LA in PCA pump
Advantages of PCA:Allows patient participation and gives
them autonomy in their treatmentRapid titrationPrecise Analgesic calculations for
scientific studiesReduced analgesic requirementsReduced incidence of breakthrough painLess staffing and monitoring concerns
A model for organizing postoperative pain management unit
A model for organizing postoperative pain management
.......In a Nutshell Excellent Post Operative analgesia means:
Improved patient satisfaction and Doctor-Patient relationship.
Better rehabilitationEarlier discharge from hospital & return to
function↓ likelihood of chronic painReduced health care costs