BACKGROUND Few studies have investigated the effect of dexmedetomidine on postoperative nausea and vomiting (PONV) in patients underwent gynecological laparoscopic surgery. We investigated if adding dexmedetomidine to a morphine-based patient-controlled analgesia (PCA) could decrease the incidence of PONV in this high-risk patient population. METHODS In this prospective, randomized, double-blind and placebo-controlled study, 122 patients underwent gynecological laparoscopic surgery were assigned into two groups. Patients in the dexmedetomidine group (Group Dex) received a loading dose of dexmedetomidine 0.4 μg/kg before the end of surgery, followed by morphine 0.5 mg/ml plus dexmedetomidine 1 μg/ml for postoperative i.v. PCA. Patients in the control group (Group Ctrl) received normal saline before the end of surgery, followed by morphine 0.5 mg/ml alone for postoperative i.v. PCA. PCA pump was programmed as followed: bolus dose 2 ml, lockout interval 8 min and background infusion at a rate of 1 ml/h. The primary outcome was the incidence of nausea and vomiting within the first postoperative 24 h. RESULTS Although there were no significant differences in regard to the total incidence of PONV (41.0% vs 52.5%, P = 0.204), PONV score, time to first onset of PONV, or the need for rescue antiemetics within the first postoperative 24 h between the two groups, the incidence of nausea and total PONV during the first 2 h period was significantly lower in the Group Dex than in the Group Ctrl (9.8% vs 24.6%, P = 0.031 and 0.031, respectively). More patients in Group Dex were over sedated or had bradycardia during the PACU compared with Group Ctrl (P = 0.040 and 0.036, respectively). CONCLUSION Our protocol in which dexmedetomidine was administered postoperatively - after a loading dose - to intravenous PCA morphine in patients undergoing gynecological laparoscopic surgery, had only early antiemetic effects, while no clinically meaningful antiemetic effect could be evidenced within the first 24 h after surgery. TRIAL REGISTRATION Current control trial registered at Chictr.org.cn: ChiCTR1800017172. Date registered: 07/16/2018.

中文翻译：

---

在基于妇科腹腔镜手术的患者中，在以吗啡为基础的镇痛中添加右美托咪定可减少术后早期的恶心：一项随机对照试验。

背景技术很少有研究研究右美托咪定对妇科腹腔镜手术患者术后恶心和呕吐（PONV）的影响。我们调查了在基于吗啡的患者自控镇痛（PCA）中添​​加右美托咪定是否可以降低该高危患者人群PONV的发生率。方法在这项前瞻性，随机，双盲和安慰剂对照研究中，将122例行妇科腹腔镜手术的患者分为两组。右美托咪定组（Dex组）的患者在手术结束前接受负荷剂量的右美托咪定0.4μg/ kg，随后接受吗啡0.5 mg / ml加右美托咪定1μg/ ml进行静脉内PCA手术。对照组（Ctrl组）的患者在手术结束前接受了生理盐水，随后是吗啡0。静脉内PCA术后仅5 mg / ml。PCA泵的程序设置如下：推注剂量2 ml，锁定间隔8分钟，本底输注速度为1 ml / h。主要结局是术后24小时内出现恶心和呕吐的发生率。结果尽管在PONV的总发生率（41.0％比52.5％，P = 0.204），PONV评分，首次开始PONV的时间或术后24小时内首次使用止吐药之间没有显着差异。两组，头2小时内恶心和总PONV的发生率在Dex组比Ctrl组显着降低（分别为9.8％和24.6％，P = 0.031和0.031）。与Ctrl组相比，更多的Dex组患者在PACU期间过度镇静或有心动过缓（分别为P = 0.040和0.036）。结论我们的方案是，在接受妇科腹腔镜手术的患者中，在负荷剂量后，右旋美托咪定是在静脉内PCA吗啡给药后，仅具有早期止吐作用，而在手术后的头24小时内没有明显的临床止吐作用。试验注册目前在Chictr.org.cn注册的对照试验：ChiCTR1800017172。注册日期：07/16/2018。ChiCTR1800017172。注册日期：07/16/2018。ChiCTR1800017172。注册日期：07/16/2018。