Adding dexmedetomidine to morphine-based analgesia reduces early postoperative nausea in patients undergoing gynecological laparoscopic surgery: A randomized controlled trial

Abstract

Purpose: Few studies have investigated the effect of dexmedetomidine on postoperative nausea and vomiting (PONV) in patients following gynecological laparoscopic surgery. We investigated if adding dexmedetomidine to a morphine-based patient-controlled analgesia (PCA) could reduce the incidence of PONV in this patient population. Methods: In this double-blind randomized-controlled trial,122 patients undergoing gynaecological laparoscopic surgery were randomly allocated to receive either a mixture of dexmedetomidine 1μg ml-1 and morphine 0.5mg ml-1 (Group Dex) or morphine 0.5mg ml-1 alone (Group Ctrl) for postoperative i.v. PCA. PCA pump was programmed as followed: bolus dose 2ml, lockout interval 8 minutes and background infusion at a rate of 1ml h-1. The primary outcome was the incidence of nausea and vomiting within 24 hours after operation. Results: The incidence of nausea and total PONV during the first 2h period was significantly lower in the Group Dex than in the Group Ctrl (10% vs 25%, P=0.031 and 0.031, respectively). There were no significant differences in regard to the total incidence of PONV (41% vs 52%, P=0.204), PONV score, time to first onset of PONV, or the need for rescue antiemetics in the first 24 hr following surgery between the two groups. Conclusions: For female patients undergoing gynecological laparoscopic surgery, adding dexmedetomidine to morphine-based PCA reduced the incidence of early postoperative nausea but not total PONV within 24h after surgery.