Effects Of Dexmedetomidine Combined With Azasetron On Postoperative Nausea And Vomiting In Adult Patients Undergoing Ambulatory Thyroidectomy

Background:Postoperative nausea and vomiting（PONV）is a common and disturbing problem in patients undergoing ambulatory thyroidectomy.This prospective trial aimed to explore whether dexmedetomidine（DEX）combined with azasetron（AZA）can further decrease the incidence of PONV in patients undergoing ambulatory thyroidectomy compared with AZA.Methods:This single-center,randomized,double-blind trial involved 172 adult patients who were to undergo ambulatory thyroidectomy.Before anesthesia,individuals were randomized to the DEX+AZA group and the AZA group.In the DEX+AZA group,patients received dexmedetomidine at 0.5μg/kg for 10 min and then the infusion rate was reduced to 0.1μg·kg^-1·h^-1until the end of surgery.Patients in the AZA group received 0.9%saline at the same infusion rates as was used in the DEX+AZA group.At the completion of surgery,10 mg of azasetron was administered to patients in both groups.The primary outcome was the incidence of 24h PONV after ambulatory thyroidectomy.The secondary outcomes included residence time in recovery room,pain scores,severity of nausea,and adverse events.Results:In terms of the incidence of nausea and vomiting within 24 hours after surgery,there was no statistical difference between the DEX+AZA group and AZA group[36%（30 of 84）vs.38%（32 of 84）;P=0.749;relative risk,0.94;95%confidence interval（CI）,0.63–1.40).The incidence of severe nausea was not significantly different between the DEX+AZA group and the AZA group[57%（12 of 21）vs 43%（9 of 21）;P=0.355;relative risk,1.33;95%CI,0.72–2.50).Conclusions:In adult patients undergoing ambulatory thyroidectomy,our results suggest that intraoperative dexmedetomidine combined with azasetron failed to significantly decrease the incidence of 24-hour PONV compared with azasetron alone.