Postoperative analgesia and vomiting, with special reference to day-case surgery: a systematic review.

BACKGROUND

Day-case surgery is of great value to patients and the health service. It enables many more patients to be treated properly, and faster than before. Newer, less invasive, operative techniques will allow many more procedures to be carried out. There are many elements to successful day-case surgery. Two key components are the effectiveness of the control of pain after the operation, and the effectiveness of measures to minimise postoperative nausea and vomiting.

OBJECTIVES

To enable those caring for patients undergoing day-case surgery to make the best choices for their patients and the health service, this review sought the highest quality evidence on: (1) the effectiveness of the control of pain after an operation; (2) the effectiveness of measures to minimise postoperative nausea and vomiting.

METHODS

Full details of the search strategy are presented in the report. RESULTS - ANALGESIA: The systematic reviews of the literature explored whether different interventions work and, if they do work, how well they work. A number of conclusions can be drawn. RESULTS-ANALGESIA, INEFFECTIVE INTERVENTIONS: There is good evidence that some interventions are ineffective. They include: (1) transcutaneous electrical nerve stimulation in acute postoperative pain; (2) the use of local injections of opioids at sites other than the knee joint; (3) the use of dihydrocodeine, 30 mg, in acute postoperative pain (it is no better than placebo). RESULTS-ANALGESIA, INTERVENTIONS OF DOUBTFUL VALUE: Some interventions may be effective but the size of the effect or the complication of undertaking them confers no measurable benefit over conventional methods. Such interventions include: (1) injecting morphine into the knee joint after surgery: there is a small analgesic benefit which may last for up to 24 hours but there is no clear evidence that the size of the benefit is of any clinical value; (2) manoeuvres to try and anticipate pain by using pre-emptive analgesia; these are no more effective than standard methods; (3) administering non-steroidal anti-inflammatory drugs (NSAIDs) by injection or per rectum in patients who can swallow; this appears to be no more effective than giving NSAIDs by mouth and, indeed, may do more harm than good; (4) administering codeine in single doses; this has poor analgesic efficacy. RESULTS-ANALGESIA, INTERVENTIONS OF PROVEN VALUE: These include a number of oral analgesics including (at standard doses): (1) dextropropoxyphene; (2) tramadol; (3) paracetamol; (4) ibuprofen; (5) diclofenac. Diclofenac and ibuprofen at standard doses give analgesia equivalent to that obtained with 10 mg of intramuscular morphine. Each will provide at least 50% pain relief from a single oral dose in patients with moderate or severe postoperative pain. Paracetamol and codeine combinations also appear to be highly effective, although there is little information on the standard doses used in the UK. The relative effectiveness of these analgesics is compared in an effectiveness 'ladder' which can inform prescribers making choices for individual patients, or planning day-case surgery. Dose-response relationships show that higher doses of ibuprofen may be particularly effective. Topical NSAIDs (applied to the skin) are effective in minor injuries and chronic pain but there is no obvious role for them in day-case surgery. RESULTS-POSTOPERATIVE NAUSEA AND VOMITING: The proportion of patients who may feel nauseated or vomit after surgery is very variable, despite similar operations and anaesthetic techniques. Systematic review can still lead to clear estimations of effectiveness of interventions. Whichever anti-emetic is used, the choice is often between prophylactic use (trying to prevent anyone vomiting) and treating those people who do feel nauseated or who may vomit. Systematic reviews of a number of different anti-emetics show clearly that none of the anti-emetics is sufficiently effective to be used for prophylaxis. (ABSTRACT TRUNCATE