What is the general post-operative analgesic protocol for adult patients undergoing surgery?

General Post-Operative Analgesic Protocol

The foundation of post-operative pain management should be scheduled multimodal analgesia combining acetaminophen 1g every 6 hours with NSAIDs (ibuprofen 600-800mg every 6-8 hours or diclofenac), supplemented by regional anesthesia when feasible, with opioids reserved strictly as rescue medication for breakthrough pain only. 1, 2, 3

Core Multimodal Regimen (Start Pre-operatively or Intra-operatively)

Non-Opioid Foundation

• Acetaminophen 1g IV or PO every 6 hours (maximum 4g/day), initiated 1-2 hours before surgery or intra-operatively and continued postoperatively 1, 2, 3
• NSAIDs or COX-2 inhibitors started pre-operatively and continued postoperatively: 1, 2, 3
  • Ibuprofen 600-800mg PO every 6-8 hours, OR
  • Diclofenac (HPβCD-diclofenac formulation preferred), OR
  • Celecoxib (COX-2 selective inhibitor)
• Dexamethasone 8-10mg IV as a single intra-operative dose for analgesic and anti-emetic effects 2, 3

This combination provides superior analgesia compared to single agents and significantly reduces opioid requirements. 1, 4 The scheduled administration (not "as needed") is critical—these medications must be given around-the-clock to maintain therapeutic levels. 2, 5

Regional Anesthesia Techniques (Procedure-Specific)

For Open Abdominal Surgery

• Mid-thoracic epidural analgesia (T8-T10 level) with low-dose local anesthetic combined with short-acting opioid provides superior analgesia and earlier return of gut function 1
• Continue for 48-72 hours postoperatively, removing by the time bowel function returns 1
• Treat hypotension from sympathetic blockade with vasopressors (not fluids) if patient is euvolemic 1

For Laparoscopic Surgery

• Spinal analgesia or transversus abdominis plane (TAP) blocks combined with IV acetaminophen reduce opioid requirements 1
• Epidural analgesia may prolong length of stay in laparoscopic cases compared to spinal techniques 1

For Orthopedic Surgery (Lower Extremity)

• Femoral nerve block or fascia iliaca block with long-acting local anesthetics (ropivacaine 0.2-0.5% or bupivacaine) 2, 3
• These blocks significantly reduce postoperative pain and opioid consumption 2

Local Wound Infiltration

• Ropivacaine 0.75% or liposomal bupivacaine infiltrated at surgical closure 2

Opioid Management (Rescue Only)

For High-Intensity Pain (VAS ≥50/100)

• Hydromorphone 1-1.5mg IV for breakthrough pain 5
• Patient-controlled analgesia (PCA) provides superior control compared to continuous infusion 3, 5
• Start with bolus injection in opioid-naïve patients 3

For Moderate-to-Low Intensity Pain (VAS <50/100)

• Tramadol PO/IV or nalbuphine as rescue medications 3
• Weak opioids (codeine-containing products like Tylenol #3 should be avoided due to poor efficacy—7-10% of patients cannot metabolize codeine due to CYP2D6 polymorphism) 5

Critical Opioid Precautions

• Avoid intramuscular administration due to associated pain 2, 3
• Minimize use in patients with obstructive sleep apnea to prevent cardiopulmonary complications 3
• For abdominal surgery, implement intestinal prophylactic regimen (stool softeners, stimulant laxatives) as opioids exacerbate postoperative ileus 5

Adjuvant Medications (Selective Use)

Gabapentinoids

• Gabapentin 300mg PO given 2 hours pre-operatively reduces pain at 2,6, and 12 hours postoperatively 2
• Reserve for patients at high risk of intense pain or chronic postoperative pain—not for routine use 2, 3
• Taper and discontinue when no longer necessary 3

Ketamine

• Low-dose ketamine (maximum 0.5mg/kg/h) after anesthesia induction for surgeries with high risk of acute pain or in pain-vulnerable patients 3
• Reduces pain scores and opioid consumption for 48 hours, particularly after major chest, abdominal, and orthopedic surgery 1

Critical Contraindications and Precautions

NSAIDs/COX-2 Inhibitors - Avoid in:

• Cardiovascular disease (increased myocardial infarction risk, especially when combining coxibs with NSAIDs) 1, 2, 3
• Significant bleeding risk or active peptic ulcer disease 2
• Aspirin-sensitive asthma 2
• Colon or rectal anastomoses—potential correlation with anastomotic dehiscence and wound healing inhibition 1, 5
• Renal dysfunction (combination of coxibs and NSAIDs affects kidney function) 1, 3

Acetaminophen Precautions

• Never exceed 4g daily 2, 3
• Use cautiously in liver disease—monitor alanine aminotransferase levels 1, 2

Monitoring and Assessment Protocol

Pain Assessment

• Evaluate pain using validated scales (Visual Analog Scale or Numerical Rating Scale) at regular intervals 2, 3
• Reassess 30-60 minutes after each intervention for both pain control and adverse reactions 3

Red Flags Requiring Escalation

• Pain intensity increases rather than decreases after day 3 5
• New symptoms suggesting complications (fever, abdominal distension, peritonitis) 5
• Breakthrough opioids required more than 2-3 times daily after day 4 5
• Significant worsening of pain—reevaluate for postoperative complications 2, 3

Follow-up

• Daily contact (telephone or email) during first postoperative days 2
• Combined nurse service with clinician supervision provides better outcomes 3

Expected Pain Trajectory and Tapering

• By day 3-4 postoperatively, pain should transition from moderate-severe to mild-moderate with optimized multimodal analgesia 5
• Most patients require minimal to no opioids by day 3-4 5
• Continue scheduled non-opioid regimen for 7-10 days total, tapering opioids over days 4-7 5

Common Pitfalls to Avoid

• Administering acetaminophen and NSAIDs "as needed" instead of scheduled—this fails to maintain therapeutic levels 2, 5
• Relying on codeine-containing products—inherently unreliable with poor NNT of 4.4 compared to NSAIDs (NNT 2.7) 5
• Fluid overload in patients with epidural analgesia—negates benefits of epidural for gut function 1
• Combining coxibs with traditional NSAIDs—increases cardiovascular and renal complications 1, 3
• Exceeding maximum toxic doses of local anesthetics in wound infiltration 3
• Neuraxial administration of magnesium, benzodiazepines, neostigmine, tramadol, or ketamine—should be avoided 3