Dexmedetomidine for antiemesis in gynecologic surgery: a meta-analysis of randomized controlled trials

Purpose: Postoperative nausea and vomiting (PONV) is a common complication after gynecological surgeries. This meta-analysis was conducted to evaluate the efficacy of dexmedetomidine on PONV after gynecological surgeries. Methods: Three main electronic databases including Pub Med, Embase and Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) were searched by two researchers independently. The meta-analysis was completed using Review Manager. Results: Eleven RCTs with 692 patients were included in this meta-analysis. Dexmedetomidine a bridged postoperative nausea [Risk Ratio (RR)=0.59, 95% confidence interval (CI): 0.44 to 0.79] and vomiting [RR=0.48, 95% CI: 0.36 to 0.64] compared with placebo. Despite of higher incidence of intra operative bradycardia [RR 2.87, 95% CI 1.08 to 7.58] and hypotension [RR 4.26, 95% CI 1.43 to 12.69], we found significant decrease in postoperative shivering [RR 0.23, 95% CI 0.13 to 0.40] and pruritus [RR 0.40, 95% CI 0.17 to 0.93] in dexmedetomidine group, as well as the pain scores [standard mean difference (SMD)-0.96, 95% CI-1.37 to-0.54]. Significant reductions in the need for intraoperative fentanyl (RR 0.10, 95% CI 0.01-0.76, I-2 0%), antiemetic (RR 0.62, 95% CI 0.39-0.99, I-2 0%) and postoperative analgesic (RR 0.18, 95% CI 0.08-0.42, I-2 0%) were also elicited. Conclusions: The current meta-analysis exhibits that dexmedetomidine is superiority to placebo in attenuating the incidence of PONV, postoperative shivering, pruritus, as well as the pain scores in patients undergoing gynecological surgeries. Still, the potential cardiovascular complications should be taken seriously.