Multimodal Approach to Postoperative Pain Management
The foundation of postoperative pain management should include a combination of acetaminophen and NSAIDs or COX-2 selective inhibitors, administered pre-operatively or intra-operatively and continued postoperatively, with opioids reserved as rescue analgesics only when needed. 1
Basic Analgesic Regimen
- Acetaminophen should be administered at the beginning of postoperative analgesia at a typical dose of 1g every 6 hours as it provides effective analgesia for about half of patients with acute postoperative pain for approximately four hours 1, 2
- Pre-emptive acetaminophen (given before surgical incision) reduces 24-hour opioid consumption and postoperative vomiting compared to post-incision administration 3
- NSAIDs should be used for moderate pain when not contraindicated, with evidence showing they reduce morphine consumption and related side effects 1, 4
- A combination of two non-opioid drugs (NSAID and acetaminophen) should always be used to reduce the need for opioid rescue analgesics 5
- A single intra-operative dose of intravenous dexamethasone 8-10 mg is recommended for its analgesic and anti-emetic effects 1, 5
Regional Anesthesia Techniques
- Regional anesthesia techniques should be utilized whenever feasible as part of multimodal analgesia 1
- For lower extremity or abdominal procedures, techniques such as:
- For upper extremity procedures:
- Brachial plexus blocks with long-acting local anesthetics 5
- Local infiltration of the surgical wound with anesthetics like bupivacaine or ropivacaine can be effective 6
Opioid Management
- Opioids should be reserved as rescue analgesics in the postoperative period 1
- For breakthrough pain in PACU (Post-Anesthesia Care Unit), intravenous fentanyl or other suitable agents can be used 5
- On the ward, consider oral or intravenous tramadol or nalbuphine as rescue medications 5
- Patient-controlled analgesia (PCA) is recommended when IV route is needed in patients with adequate cognitive functions 1
Adjuvant Medications
- Glucocorticoids have shown benefit in postoperative pain outcomes, with dexamethasone 10 mg reducing pain scores, opioid consumption, and enabling earlier ambulation 5
- Gabapentinoids (pregabalin 75-150 mg every 12 hours or gabapentin 300-600 mg every 8 hours) can be considered for patients with inadequate pain control from basic analgesics 6, 7
- Ketamine (maximum dose of 0.5 mg/kg/h) can be considered in surgeries with high risk of acute pain 1
Special Considerations
Pediatric Patients
- For pediatric patients, dosing should be weight-based:
- Ibuprofen: 10 mg/kg every 8 hours
- Diclofenac: 1 mg/kg every 8 hours
- Paracetamol: 15 mg/kg every 6 hours (max daily dose: 60 mg/kg) 5
Patients with Allergies to NSAIDs and Opioids
- Maintain paracetamol as the base of treatment 6
- Consider adding gabapentinoids if paracetamol alone is insufficient 6
- Alpha-2 agonists like dexmedetomidine may be useful alternatives 6
Common Pitfalls and Caveats
- NSAIDs should be used cautiously in patients with colon or rectal anastomoses due to potential correlation with dehiscence 1
- Avoid exceeding maximum toxic doses of local anesthetics, particularly for peri-prosthetic orthopedic infiltrations 1
- Ketorolac (Toradol) should not exceed 120 mg daily and treatment duration should not exceed 5 days 8
- Avoid using ketorolac in patients with aspirin/NSAID-induced asthma, pregnant patients, or those with cerebrovascular hemorrhage 8
- Monitor for side effects of gabapentinoids, such as sedation and dizziness, especially in the first 24-48 hours 6
- Dexmedetomidine can cause bradycardia and hypotension, requiring careful monitoring 6
Procedure-Specific Recommendations
Total Hip Arthroplasty
- Paracetamol in combination with NSAIDs or COX-2 inhibitors is recommended 5
- A single dose of dexamethasone 8-10 mg has shown improved postoperative pain outcomes 5
- Local infiltration analgesia can be considered, though evidence is inconsistent 5