Dexmedetomidine and cardiac protection for non-cardiac surgery: a meta-analysis of randomised controlled trials.

We conducted a systematic review of the effects of dexmedetomidine on cardiac outcomes following non-cardiac surgery. We included prospective, randomised peri-operative studies of dexmedetomidine that reported mortality, cardiac morbidity or adverse drug events. A PubMed Central and EMBASE search was conducted up to July 2007. The reference lists of identified papers were examined for further trials. Of 425 studies identified, 20 were included in the meta-analysis (840 patients). Dexmedetomidine was associated with a trend towards improved cardiac outcomes; all-cause mortality (OR 0.27, 95% CI 0.01-7.13, p = 0.44), non-fatal myocardial infarction (OR 0.26, 95% CI 0.04-1.60, p = 0.14), and myocardial ischaemia (OR 0.65, 95% CI 0.26-1.63, p = 0.36). Peri-operative hypotension (26%, OR 3.80, 95% CI 1.91-7.54, p = 0.0001) and bradycardia (17%, OR 5.45, 95% CI 2.98-9.95, p < 0.00001) were significantly increased. An anticholinergic did not reduce the incidence of bradycardia (p = 0.43). A randomised placebo-controlled trial of dexmedetomidine is warranted.