Influence of dexmedetomidine on cardiac complications in non-cardiac surgery: a meta-analysis of randomized trials

Background The cardiac protection of dexmedetomidine (Dex) in peri-operative period of patients with non-cardiac surgery is still controversial. Aim of the Review We aimed to evaluate the influence of Dex on cardiac complications in peri-operative period of non-cardiac surgery by using a meta-analysis. Methods PubMed, Embase, the Cochrane library and Springer databases were searched for relevant studies. Patients in the eligible studies were divided into Dex group and placebo group. Relative risk (RR) and the 95 % confidence interval (CI) were calculated to evaluate the outcomes including all-cause mortality, myocardial infarction, myocardial ischaemia, hypotension and bradycardia. Subgroup analysis was performed based on the dosage of Dex. Publication bias was assessed by Egger's test. Results Twenty double-blind randomized controlled trials containing 1157 patients were included in this meta-analysis. The pooled results showed no significant difference between Dex group and placebo group in peri-operative myocardial infarction, myocardial ischaemia and all-cause mortality. However, Dex group showed higher risk of hypotension (RR = 1.46, 95 % CI 1.07, 2.01) and bradycardia (RR = 1.98, 95 % CI 1.33, 2.95) than that of placebo group. In addition, significant publication bias was found among studies involving hypotension and bradycardia. In subgroup analysis, the risk of bradycardia was significantly higher in 1.0 mu g/kg Dex group than that in placebo group. Besides, a higher risk of hypotension in 0.5 mu g/kg Dex group than that in placebo group was found. Conclusions Dex supplement might not reduce the risk of cardiac complications but increases the risk of hypotension and bradycardia in peri-operative period of patients who underwent non-cardiac surgeries.