Analgesics for pain after traumatic or orthopaedic surgery: what is the evidence--a systematic review

To assess analgesic drugs in the treatment of postoperative pain after traumatic and orthopaedic surgery (TOS).

A systematic review of randomised clinical trials (RCTs).

Electronic PubMed, EMBASE, The Cochrane Library, and hand searches.

RCTs of analgesics administered by oral, intramuscular, intravenous, subcutaneous or rectal route, were compared to other analgesics or placebo, in patients under TOS. Study design, characteristics of the study population, analgesic drugs tested, pain intensity and pain relief scores, and adverse effects were assessed.

Ninety-two RCTs (9,596 patients) met our inclusion criteria. Forty-two (46%) were placebo-controlled, and 50 (54%) were direct comparisons between non-opioid, opioid, and/or combinations of both. Patients' mean age (SD) was 49 years (18). In most trials, gastrointestinal ulcer, liver and renal diseases were exclusion criteria. Only 30 trials (33%) were double-blind and reported standardised outcomes of pain intensity and pain relief; 19 of these were single-dose, and follow up of analgesic effects lasted no more than 12 h in 23 (77%). Globally, only nine trials (10%) were double blind, described dropouts or withdrawals, performed analysis by intention to treat, and reported the effects magnitude.

Evidence from RCTs on the treatment of postoperative pain after TOS is inadequate for clinical decision making. Assessment of analgesics in pain after TOS should be based on agreed clinically relevant outcomes, in representative patients, and for longer observation periods. In addition, it should include direct comparisons between candidate drugs or their combinations and between various drug administration schedules.