The effect of preoperative PC6 intradermal acupuncture combined with dexamethasone and palonosetron on preventing postoperative nausea and vomiting in bilateral orthognathic surgery: a research protocol for blind, double-dummy, randomized controlled clinical trial

Background: Pain and postoperative nausea and vomiting (PONV) are the most prevalent postoperative complications following orthognathic procedures. Acupuncture therapy is advocated as one of the treatment alternatives for preventing PONV. This trial aims to investigate the efficacy of preoperative intradermal acupuncture in combination with dexamethasone and palonosetron in high-risk patients undergoing bimaxillary orthognathic surgery, employing a multimodal risk-reduction strategy aligned with consensus guidelines. Methods: This single-center, double-blind, randomized controlled trial will enroll 216 participants allocated to two groups: group A, the acupoint stimulation group and group B, the sham stimulation group. All subjects will receive standardized PONV prophylaxis including dexamethasone 5 mg IV, palonosetron 0.075 mg IV, target-controlled propofol infusion (0.5 μg/mL), and laryngeal packing following anesthesia induction. Patients in both groups receive two sterile thumb-tack needles - one real needle and one identical-appearing sham needle without a pointed tip. In group A, the real needles are placed at the PC6 acupoint, and the sham needles are placed at the sham acupoint on the forearm. In group B, the real needles are placed at the sham acupoint, while the sham needles are placed on the PC6 acupoint. Finally, all patients will have the sterile opaque patches applied to each acupoint for allocation concealment. The needles will remain in place up to 24 h postoperatively at least. The primary outcome will be the incidence of PONV at 24 h postoperatively. Secondary outcomes will include the incidence rates of PONV at different postoperative intervals and a 15-point quality of life recovery score at 24 h postoperatively. Discussion: Despite dual-mechanism pharmacological prophylaxis, orthognathic surgery patients exhibit persistent postoperative nausea rates approaching 50%. It is necessary to introduce a third combined measure to prevent PONV. This trial aims to investigate a novel triple-modality prophylactic strategy for PONV mitigation in bimaxillary orthognathic procedures. Systematic review registration: https://itmctr.ccebtcm.org.cn/mgt/project/view/1966089260633292800, Identifier ITMCTR2025001713.