Effectiveness of transcutaneous electrical acupoint stimulation for postoperative nausea, vomiting and pain in cancer patients: a systematic review and meta-analysis of randomized controlled trials

Objective To evaluate the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) in relieving postoperative pain and reducing the incidence of postoperative nausea and vomiting (PONV) in patients undergoing cancer surgery. Methods A systematic search was conducted in PubMed, Web of Science, Embase, the Cochrane Library, CNKI, and Wanfang databases to identify randomized controlled trials (RCTs) published between January 2015 and May 2025. Postoperative pain scores at different time points, assessed using the visual analog scale (VAS) or numerical rating scale (NRS), as well as the incidence of PONV, postoperative nausea (PON), and postoperative vomiting (POV), were extracted. Subgroup analyses were performed according to the timing of TEAS intervention and pain assessment methods. The risk of bias was evaluated using the Cochrane Risk of Bias (RoB) tool, and the meta-analysis was conducted using RevMan 5.4 software. Results A total of 16 randomized controlled trials involving 2,017 postoperative cancer patients were included (1,125 in the TEAS group and 892 in the control group). Meta-analysis of 13 studies showed that TEAS significantly reduced postoperative pain scores (SMD = −1.19, 95% CI: −1.42 to −0.95, p < 0.00001). Eleven studies indicated that TEAS decreased the incidence of PONV (RR = 0.47.95% CI:0.37~0.61, P