This document discusses key concepts in post-operative pain management. It defines types of pain and outlines consequences of poorly managed acute post-operative pain such as increased risk of chronic pain, medical complications, and decreased patient satisfaction. The document reviews various analgesic agents including acetaminophen, NSAIDs, opioids, local anesthetics, and the benefits of a multimodal approach. Regional anesthesia techniques like peripheral nerve blocks and epidural analgesia are presented as effective options for post-operative pain control.

1. kEY cONCEPTS iN pOST-OPERATIVE pAIN
mANAGEMENT
Dr Pranav Bansal
Associate Professor
Dept of Anaesthesiology
BPS Govt. Medical College for Women, Khanpur Kalan, Sonepat

2. 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?

3.  ACUTE PAIN
 CUTANEOUS PAIN
 DEEP SOMATIC PAIN
 VISCERAL PAIN
 CHRONIC PAIN
 REFERRED PAIN
 NEUROPATHIC PAIN
 PHANTOM PAIN
TYPES OF PAIN

4. Pain Assessment Visual Analogue
Scale

5. Why Treat Pain?
 Basic human right!
 Moral responsiblity
 ↓ suffering and post operative complications
 ↓ likelihood of chronic pain development
 ↑ patient satisfaction

6. Consequences of poorly managed
acute post-operative pain
 The Patient may suffer from:
 CVS: Tachycardias, dysrhythmias, Ischaemia
 Resp: atelectasis, pneumonia
 GI: ileus, anastamosis failure
 Hypercoagulable state: DVT
 Impaired immunological state:
Delayed wound healing

7.  Psychological:
 Anxiety, Depression, Fatigue, Sleep
Deprivation
 Chronic Post-surgery Pain
 ForThe Healthcare professional:
 Low Morale
 Complaints to/towards/against Institute
 Litigation
Consequences of poorly managed
acute post-operative pain

8. CAUSES OF VARIATION IN ANALGESIC
REQUIREMENTS
 Site and type of surgery
 Age, gender
 Psychological factors
 Pharmacokinetic variability
 Pharmacodynamic variability

10. Surgical pain
Mild Intensity
Pain
Herniotomy
Varicose vein
Gynecological
laparotomy
Moderate Intensity
Pain
Hip replacement
Hysterectomy
Maxillofacial
Severe Intensity
Pain
Thoracotomy
Major abdominal
surgery
Knee surgery
Paracetamol /NSIADs /
weak opiods
Wound infiltration
Regional block analgesia
Add weak opioid or
rescue analgesia
Paracetamol /NSIADs
+Wound infiltration
Peripheral nerve block
Systemic opioids
PCA
Paracetamol /NSIADs
+ Wound infiltration
Epidural anesthesia
Systemic opioids
PCA
Treatment modality
Surgical procedure

11. WHO Analgesic Ladder

12. WHO analgesic guidelines
 Oral medications whenever possible
 Dose “by the clock” – but always have “as
needed”medications for breakthrough pain
 Titrate the dose
 Use appropriate dosing intervals
 Be aware of relative potencies
 Treat side effects

13. Multimodal (Balanced) Analgesia
Using 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 alone
 Can provide additive or synergistic effects
 Provides better analgesia with less side
effects (mainly opiate related S/E)
Always consider multimodal analgesia when treating pain

14. The administration of analgesic agents prior to an
injury in order to prevent development of central
nervous system hyperexcitability or
Preemptive analgesia

15. Methods to Treat Postoperative Pain
 Pharmacologic (Medications (PO/IV/PR)
 Acetaminophen (Paracetamol)
 NSAIDs
 Opioids
 Alpha-2 agonists
 Procedures
 Regional Anesthesia
 LA infiltration at incision site
 Nonpharmacologic Approaches
 Music and Audioanalgesia
 Transcutaneous electrical nerve stimulation (TENS)

16. Site of Action of Analgesics

17. Acetaminophen (Paracetamol)
 First-line treatment if no contraindication
 Mechanism: thought to inhibit prostaglandin
synthesis in CNS → analgesia, antipyretic
 Typical dose: 650 to 1000 mg PO every 6H
 Max dose: 4 g / 24 hrs from all sources
 Warning: ↓ dose / avoid in those with liver
damage

18. NSAIDs
 First-line treatment
 Mechanism
 Block cyclooxygenase (COX) enzyme → ↓
prostaglandin synthesis
 COX-2 → Prostaglandins → pain, inflammation,
fever
 COX-1 → Prostaglandins → gastric protection,
hemostasis
 No physical dependence
No tolerance
Ceiling effect

19. NSAID
Drug Dosage Maximum daily
dose
Diclofenac
Piroxicam
Ibuprofen
Ketorolac
Ketoprofen
50 mg PO bd/tds
20 mg OD
200-800 mg q 6 hr.
3 x 30-40 mg/day
(only IV form)
4 x 50 mg/day
200 mg
40 mg
3200 mg
Cox-2 inhibitor
Celecoxib
Parecoxib
100-200 mg PO bid
40 mg followed by
1-2 x 40 mg/day
(IV form)
400 mg

20. NSAIDs
 Warnings: ↓dose / avoid if
 GI ulceration
 Bleeding disorders / Coagulopathy
 Renal dysfunction
 High cardiac risk – COXII inhibitors
 Asthma
 Allergy

21. Tramadol
 Multiple mechanism
 Weak µ-receptor agonist
 Inhibit serotonin & NE reuptake
 Application :
Mild to Moderate Post-op pain
 Dose : 50-100 mg PO q 4-6 hr.
 Max. 400 mg/d
 Side effect: Nausea and Vomitting

22. Opioids
 Essential element of pain management
 Mechanism
 Action on opioid receptor
 Located mainly in spinal cord & brain stem, some in
peripheral tissue

23. Opioids receptors
Receptors
Mu (μ or OP3)
μ1
μ2
Kappa (κ or OP2)
Delta (δ orOP1)
Sigma(σ)
Clinical effect
Analgesia, sedation, euphoria
Resp. depression, physical dependence
Spinal analgesia, resp. depression
Analgesia, resp. depression
Dysphoria, hallucination, tachycardia
hypertension

24. Opioids
1.Agonists
: stimulate receptor
: no ceiling effect ( no limit mg/kg)
: moderate to severe pain
: Codiene, morphine, pethidine, fentanyl,
methadone

25. Opioids
2. Partial agonists
: ceiling effects eg. Buprenorphine

26. Opioids
3. 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

27. Side Effects include:
 Nausea / Vomiting, Pruritus, Constipation, Urinary
Retention, Ileus, Sedation, Respiratory Depression,
Tolerance
 Opioid Overdose
Manifests as Somnilence, respiratory depression,
bradycardia, miosis.
 Management:
 Stimulate patient
 Attach Monitors/ IV Lines and record Vitals
 Airway, Breathing, Circulation
 Shift to ICU
Opioids

28. Opioid Overdose
 Opioid Reversal
 Naloxone - Pure antagonist at all
the Opioid receptors
 Reverses effects of opioid
overdose (for 30-45min)
0.4mg ampuole
Dilute: 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

29. 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
action
 Bupivacaine (Sensorcaine) – slow onset, longer
duration
 Ropivacaine: longer duration, less cardiotoxic

30. Agents
Lidocaine
-infiltration
-epidural
-plexus or nerve
Bupivacaine
-infiltrate
-epidural
-plexus or nerve
% solution
0.5-1
1-2
0.75-1.5
0.125-0.25
0.25-0.75
0.25-0.5
Duration(h)
1-2
1-2
1-3
1.5-6
1.5-6
8-24+
Max dose
7mg/kg
3 mg/kg
Local Anaesthetics

31. Potential side effects of Local
anesthetics
- Residual motor weakness
- Peripheral nerve irritation
- Cardiac arrhythmias
- Allergic reactions
-Sympathomimetic effects (due to vasoconstrictors)

32. Regional Anesthesia techniques in
PostOperative Pain Management

33. Peripheral nerve blocks
Ilioinguinal/hypogastric : herniorrhaphy
Brachial plexus : arm, hand
Thoracic: Intrapleural Regional Anaesthesia (IPRA),
Paravertebral, intercostal blocks
Penile : circumcision
Intercostal/paravertebral : breast
Lower Limb: Femoral, sciatic, popliteal, ankle
Paracervical : F&C, D&C, cone biopsy
Abdomen:TAP blocks

34. Epidural Analgesia
 Epidural 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

35. Patient Controlled Analgesia Pump

36. Regime for using IV Morphine in PCA pump

37. Regime for using Epidural Opioids with LA in
PCA pump

38. Advantages of PCA:
 Allows patient participation and gives them
autonomy in their treatment
 Rapid titration
 Precise Analgesic calculations for scientific
studies
 Reduced analgesic requirements
 Reduced incidence of breakthrough pain
 Less staffing and monitoring concerns

39. A model for organizing postoperative
pain management unit

40. A model for organizing
postoperative pain management

41. .......In a Nutshell
Excellent Post Operative
analgesia means:
 Improved patient satisfaction and Doctor-
Patient relationship.
 Better rehabilitation
 Earlier discharge from hospital & return to
function
 ↓ likelihood of chronic pain
 Reduced health care costs