Postoperative pain

Background

• Acute pain is common after surgery, and for many it will be moderate or severe
• Postoperative pain is associated with poor clinical outcomes, patient dissatisfaction, and long-term morbidity including chronic pain
• Normal healing can take up to 3 months; pain lasting beyond this time is assumed to be pathologic

Clinical Manifestations

• Typical postoperative pain is nociceptive, well-localized, described as sharp, aching, or throbbing

Prognosis and Complications

• Results in decreases in quality of life, sleep, physical activities, and mental status
• May result in chronic pain

Management

Preoperative

• Evaluation and assessment for risk of severe postoperative pain
• Consider referral to Acute Pain Service

Intraoperative

• Regional or neuraxial anaesthetic is preferred for those at high risk of postoperative pain
• Intraoperative lidocaine or ketamine infusions can be considered

Postoperative

• Comprehensive daily pain assessment

Mild Pain

• First-line: acetaminophen 500 to 1000 mg PO q6h for 3 to 5 days, plus one of:
  • Celecoxib 100 to 200 PO bid for 3 to 5 days, or
  • Ibuprofen 200 to 800 mg PO bid for 3 to 5 days, or
  • Naproxen 250 to 500 mg PO bid for 3 to 5 days
• If NPO: acetaminophen 1000 mg IV q6h (if available) for 3 to 5 days plus ketorolac 15 mg IV q8h for 3 days
• As well as one of the following:
  • Oxycodone 5 to 10 mg PO q4h prn
  • Hydromorphone 1 to 2 mg PO q4h prn
  • Morphine 5 to 15 mg PO q4h prn

Moderate-to-Severe Pain

• Standing acetaminophen and NSAIDs, if possible
• Consider patient-controlled anaesthesia (PCA)
• Consider postoperative regional anaesthetic
• Consider intravenous ketamine
  • Intermittent infusion: 0.1 mg/kg IV q4h, titrated to maximum dose of 0.35 mg/kg
  • Continuous infusion: 0.1 mg/kg/h IV continuous infusion, titrated to maximum dose 0.25 mg/kg/h
• Consider lidocaine infusion
• Consider cannabinoids
• Consider gabapentinoids