Pain Management in Surgical Patients

Introduction to Alternative Opioids

For patients with morphine allergy, alternatives such as fentanyl (approximately 7.5 times more potent than IV morphine) and hydromorphone (approximately 5 times more potent than morphine) can be considered, as they cause less histamine release than morphine, making them beneficial for patients with histamine-mediated allergies, particularly useful in patients with renal dysfunction due to fewer active metabolites, available in transdermal patches for stable pain management 1, 2, 3

Administer 1g IV acetaminophen every 6 hours to reduce opioid consumption, can be started preoperatively as part of preemptive analgesia, reduces opioid consumption by approximately 6.34 mg morphine equivalent per 24 hours 4
Use NSAIDs if not contraindicated, as they reduce opioid consumption by approximately 10.18 mg morphine equivalent per 24 hours, significantly reduce nausea and vomiting compared to placebo, but caution is needed to monitor for bleeding risk, especially at surgical sites, and avoid in patients with renal dysfunction (eGFR <50 mL/min) 4, 5
Consider COX-2 Inhibitors, as they reduce opioid consumption by approximately 10.92 mg morphine equivalent per 24 hours, but are contraindicated in patients with history of atherothrombosis 5
Regional Anesthesia Options, such as thoracic epidural analgesia (TEA) for open abdominal surgery, and transversus abdominal plane (TAP) blocks for minimally invasive surgery, can be considered 6
IV Lidocaine Infusion, with a bolus of 1-2 mg/kg followed by 1-2 mg/kg/h, decreases intraoperative anesthetic requirements and postoperative pain, improves return of bowel function, but requires continuous ECG monitoring during infusion 5, 6

Dexamethasone, 8 mg IV at induction, reduces postoperative pain 5
Gabapentinoids can be considered as part of multimodal regimen for neuropathic pain component 4
Regular assessment of pain using validated pain scales, monitor for respiratory depression, especially with opioid therapy, and reassess pain control and adverse effects at appropriate intervals 4
Vital signs should be monitored regularly, especially respiratory rate and oxygen saturation, as recommended by the American College of Critical Care Medicine 7

Patient-Controlled Analgesia (PCA) is recommended for patients with adequate cognitive function, start with bolus injection in opioid-naïve patients, and consider hydromorphone PCA as an alternative to morphine PCA 4
Avoid intramuscular route for analgesic administration 4
Do not rely on monotherapy, multimodal analgesia is superior for pain control and reduces side effects 4
Avoid NSAIDs in combination with curative doses of anticoagulants due to increased bleeding risk 5
Do not underestimate the importance of regular pain assessment, inadequate assessment leads to inadequate treatment 4
The National Comprehensive Cancer Network recommends morphine as the first-line opioid for acute severe pain management in patients with fractures, due to its rapid onset, established efficacy, and predictable pharmacokinetics 2
For opioid-naïve patients with severe pain needing urgent relief, parenteral opioids administered intravenously are recommended by the National Comprehensive Cancer Network 2
Consider adding non-opioid analgesics (acetaminophen, NSAIDs if not contraindicated) to reduce total opioid requirements, as recommended by the World Journal of Emergency Surgery and the European Society of Emergency Medicine 8
Proper immobilization of fractures will significantly reduce pain requirements, according to the World Journal of Emergency Surgery and the European Society of Emergency Medicine 8

The American College of Critical Care Medicine recommends titration of IV morphine every 15 minutes as required until adequate pain control is achieved 7
If a patient receives two bolus doses in an hour, it's reasonable to consider continuous infusion by doubling the hourly rate, according to the American College of Critical Care Medicine 7
Avoid abrupt discontinuation of opioids to prevent withdrawal symptoms, as advised by the National Comprehensive Cancer Network 9
In patients with significant renal dysfunction, fentanyl may be preferred as it has fewer active metabolites, as suggested by the National Comprehensive Cancer Network and the European Society for Medical Oncology 2, 9