General Medical Information

Postoperative Pain

David M. Barrs

Postoperative pain is often inadequately controlled as a result of a variety of factors, including fear of side effects (e.g., respiratory depression, nausea), fear of addiction, or failure to give medicine as prescribed. The otolaryngologist should give consideration to pain control in the preoperative and postoperative periods. A complete explanation of the procedure to the patient can alleviate anxiety that contributes to pain. Continuing concern and reassurance postoperatively are also important in the psychologic management of pain relief.

Pharmacologic treatment of postoperative pain revolves around the administration of systemic opioids. Patient-controlled analgesia is an increasingly popular method of delivering postoperative pain relief without the delay associated with formulating i.v. or intramuscular injections. Morphine remains the drug of choice for analgesia in severe pain. Meperidine and codeine are frequently used in otolaryngology, but methadone and buprenorphine also can be considered. Buprenorphine is a mixed narcotic agonist and antagonist that has a longer duration of action than morphine. To be effective, systemic opioids must be given in adequate dosage in the immediate postoperative period. Consideration should be given to i.v. administration, which is more reliable than intramuscular or oral administration. The principal side effect in the postanesthetic period is respiratory depression, and it may be particularly pronounced in elderly patients. Respiratory depression can be treated with 0.4 mg of naloxone given intravenously. In a mixed agonist-antagonist like buprenorphine, naloxone may have less effect, and 1.0 to 1.5 mg/kg of doxapram given intravenously is preferable. Opioids may cause vasodilatation and secondary hypotension, which can usually be treated by elevation of the feet.

NSAIDs can play an important adjunctive role in postoperative pain relief. The combination of NSAIDs and opioid potentiates analgesia. NSAIDs are antiinflammatory, antipyretic, and decrease platelet adhesion, which has a beneficial effect on the prevention of deep venous thrombosis. The side effect of gastrointestinal bleeding is minimal, but it is a concern. In most otolaryngology operations, the routine use of NSAIDs should be considered. Other adjunctive procedures, such as transcutaneous electrical nerve stimulation, cryoanalgesia, and epidural-intrathecal opioid administration, are treatment modalities used in other specialties but less frequently in head and neck surgery.