Approach to management

Postoperative pain is best dealt with by pre-empting the build up of pain and titrating the analgesic to the individual's clinical response.

• explain to the patient about the nature of the operation and pain beforehand; this has been shown to reduce the requirements for analgesia
• review the analgesic content of premedication, the intraoperative period and the early postoperative period
• assess the present level of patient pain; ideally this should be done by the same clinician at each stage to establish a standardized trend:
  • physiological indices: anxiety; sweating; restlessness; immobility; nausea; vomiting; pallor; tachycardia; tahcypnoea; hypertension; dry mouth; large pupils
  • patient assessment:
    • verbal description, e.g. "discomfort" to "agony"
    • numerical rating, e.g. scale of 1 to 10
    • visual analogue, e.g. sliding scale
• if pain relief is insufficient, administer a small dose of analgesic and wait a period long enough for it to have acted, e.g. at least 10 minutes for intravenous opioids. If the pain is still not relieved, repeat the dose. If the pain is partly relieved, give a smaller dose.
• pain relief is then managed by regular application of a dose of analgesic suitable to the circumstances, i.e. the amount of patient pain, the likelihood of complications with high doses of analgesic, and whether the pain is of a magnitude predicted by the operation. Hence, thoracic injury is more painful than abdominal injury, and the longer an operation lasts, the more analgesia is required. Common types of analgesia at this stage include intramuscular and continuous infusion/patient-demand infusion intravenous opioids.
• consider a combination of drugs and/or other techniques as "balanced analgesia" is effective at reducing the need for one agent, e.g. opioids, with dangerous side effects