Incremental effect of adding dexmedetomidine to low-dose droperidol on postoperative nausea and vomiting in adults undergoing laparoscopic surgery: a randomized controlled trial

Abstract Background This randomized controlled trial evaluated whether the addition of intraoperative dexmedetomidine (DEX) to low-dose droperidol further reduces postoperative nausea and vomiting (PONV) in adults undergoing laparoscopic surgery. Methods A total of 116 patients were randomly allocated to either the dexmedetomidine plus droperidol group (DEX + DRO, n = 58) or the droperidol-alone group (DRO, n = 58). Before anesthesia induction, the DEX + DRO group received dexmedetomidine (0.5 µg/kg infused over 10 min), followed by continuous infusion (0.4 µg/kg/h) until surgical closure. The DRO group received volume-matched 0.9% saline at equivalent rates. Five minutes before the end of surgery, all patients received 0.625 mg droperidol. PONV was assessed at 0–24 h postoperatively across three intervals: postanesthesia care unit (PACU), from PACU discharge to 6 h postoperatively (PACU—6 h), and 6–24 h. The primary outcome was the 24‑h PONV incidence. Secondary outcomes included pain intensity, anxiety scores, and adverse events (hypotension, bradycardia, hypoventilation, oversedation, and agitation). Results All 116 patients were analyzed. The DEX + DRO group had a significantly lower 24‑h PONV incidence (29% vs. 48%; χ 2 = 4.39, p = 0.036) and lower PONV rates during the PACU—6 h period (28% vs. 47%, χ 2 = 4.47, p = 0.034). No significant differences were observed in rescue antiemetic requirements, pain scores at any time point, or adverse events. Conclusion Compared with low-dose droperidol alone, the addition of intraoperative DEX significantly reduced the 24‑h incidence of PONV in adults undergoing laparoscopic surgery, an effect primarily driven by reduction during the early postoperative period (PACU discharge to 6 h). Trial Registration This trial was registered with the Chinese Clinical Trial Registry ( www.chictr.org.cn , ChiCTR2400081794) on March 12, 2024.