Preoperative electroacupuncture for postoperative nausea and vomiting in laparoscopic gynecological surgery: a randomized controlled trial

OBJECTIVE: We aimed to evaluate the effectiveness and safety of preoperative electroacupuncture (EA) on the incidence of postoperative nausea and vomiting (PONV), and severity of postoperative pain, in gynecological patients undergoing laparoscopic surgery. The effects of EA administered at different preoperative time points were compared. METHODS: A total of 413 patients undergoing elective laparoscopic gynecological surgery were randomly allocated into 4 groups receiving EA the day before surgery (Group Pre, n = 103), 30 min before (Group 30, n = 104) or both (Group Comb, n = 103), or usual care alone (Group Usual, n = 103). All acupuncture groups had usual care. The incidence of PONV and pain at 24 h were primary outcomes. Secondary outcomes included the severity of postoperative nausea, vomiting and pain, requirement for antiemetic medication and quality of recovery (QoR)-15 scores after surgery. RESULTS: There were significant differences between the four groups in nausea and vomiting incidence (0-24 h), postoperative antiemetic use (0-48 h), and postoperative pain (0-6 h), with the EA groups recording the lowest levels. Regarding primary outcomes, incidence of nausea and vomiting at 6-24 h was 28/11/18/11% (p = 0.003) 23/5/8/9% (p < 0.001), respectively, for Groups Usual/Pre/30/Comb. Accordingly, EA reduced the incidence of nausea and vomiting at 6-24 h by 61/34/60% and 79/65/61% for Groups Pre/30/Comb, respectively. Regarding secondary outcomes, incidence of nausea and vomiting at 0-6 h was 20/9/11/7% (p = 0.013) and 17/7/9/6% (p = 0.021), respectively, for Groups Usual/Pre/30/Comb. Rescue antiemetics at 0-6 h were required by 18/4/11/4% (p = 0.001) in Groups Usual/Pre/30/Comb. The mean numerical rating scale (NRS) pain score (0-10) at 0-6 h was significantly different between groups (2.45/1.89/2.01/1.97 for Groups Usual/Pre/30/Comb, p = 0.024). There were no significant differences between the three EA-treated groups. CONCLUSION: In gynecological patients undergoing laparoscopic surgery and treated with multimodal antiemetic methods, one session of preoperative EA may be a safe adjunctive treatment for PONV prophylaxis. Optimal timing of EA requires further verification. TRIAL REGISTRATION NUMBER: ChiCTR-INR-16010035 (Chinese Clinical Trial Registry).