Comparative effectiveness of acupoint stimulation for preventing postoperative nausea and vomiting after general anesthesia: a network meta-analysis of randomized trials

Objective: The objective was to systematically evaluate the effectiveness of different acupoint stimulation techniques in preventing postoperative nausea and vomiting (PONV) after general anesthesia. Methods: The authors searched PubMed, Cochrane Library, Web of Science, and Embase for relevant papers, about the effect of acupoint stimulation for preventing PONV from their inception to 31 July 2023. Two reviewers performed study screening, data extraction, and risk of bias assessment. The authors focused on patient important outcomes, including the incidence of PONV, postoperative nausea (PON), or postoperative vomiting (POV), and the number of patients requiring antiemetic rescue. The authors conducted network meta-analyses to estimate the relative effectiveness between different acupoint stimulation using Stata 17.0 and Revman 5.3 software. Results: The authors included 50 randomized trials involving 7372 participants (median age: 43.5 years, female: 73.3%). The network meta-analysis revealed that compared with the control (sham acupoint stimulation or blank control), antiemetic alone could significantly reduce the incidence of POV (RR 0.49, 95% CI: 0.36–0.69), but could not significantly reduce the incidence of PONV and PON (RR 0.49, 95% CI: 0.36–0.69; RR 0.81, 95% CI: 0.59–1.10; respectively); both TEAS and electroacupuncture alone significantly reduced the incidence of PONV, PON, and POV, and combined with antiemetic was usually more effective than single acupoint stimulation. Conclusions: Both TEAS and electroacupuncture, with or without antiemetic, could significantly reduce the incidences of postoperative nausea and vomiting after general anesthesia.