Best evidence in anesthetic practice Prevention: Dimenhydrinate prevents postoperative nausea and vomiting

Structured abstractQuestionIn patients undergoing surgery, does prophylactic dimenhydrinate reduce the frequency of postoperative nausea and vomiting (PONV) compared to placebo?Data sourcesStudies were identified by computerized searches (MEDLINE, EMBASE, Cochrane Library) up to June 2001, citation review, and hand searches of locally available anesthesia journals. No language restrictions were applied.Study selectionStudies were selected if they were randomized controlled trials comparing prophylactic dimenhydrinate or diphenhydramine to placebo.Data extractionData was extracted in duplicate on postoperative nausea, postoperative vomiting, and PONV.Main resultsEighteen trials with a total of 3,045 patients met the inclusion criteria. Compared to placebo, dimenhydrinate reduced the frequency of early (0–6 hr postoperatively) PONV (relative benefit [RB] 1.21; 95% confidence interval [CI] 1.07–1.21) and overall (0–48 hr postoperatively) PONV (RB 1.51; 95% CI 1.27–1.78; Table). Dimenhydrinate reduced overall PONV in subgroups of adults, children, and routes of administration (iv/im orpr).ConclusionProphylactic dimenhydrinate reduces PONV up to 48 hr after surgery.FundingNot reported.