Effects of transcutaneous auricular vagus nerve stimulation on perioperative anxiety in patients undergoing laparoscopic colorectal cancer surgery: a study protocol for a double-blind, prospective, single-centre, randomised controlled trial

BACKGROUND: Perioperative anxiety, characterised by tension, worry or fear from preoperative to postoperative phases, is prevalent among patients with colorectal tumour. It exacerbates intraoperative haemodynamic instability, postoperative pain and delirium and prolongs hospital stay, underscoring the need for effective management. Transcutaneous auricular vagus nerve stimulation (TaVNS) represents a promising non-invasive intervention for anxiety alleviation. This study aims to evaluate the efficacy of TaVNS in reducing perioperative anxiety in patients with colorectal tumour, thereby providing evidence for its clinical application. METHODS AND ANALYSIS: This randomised, prospective, double-blind, single-centre controlled trial will enrol 120 patients undergoing laparoscopic surgery for colorectal tumours. These patients will be randomly assigned to either the TaVNS group (n=60) or the control group (n=60). Both groups will receive corresponding stimulation for half an hour on the day before surgery and after extubation postoperatively. For the primary outcome measure, differences in anxiety scores will be assessed using the Hospital Anxiety and Depression Scale (HADS) on postoperative days 1-3 and 3 months postoperatively in patients with laparoscopic colorectal tumours. For the secondary outcome measures, the incidence of postoperative delirium, pain scores, Richards-Campbell sleep questionnaire scores and the occurrence of various postoperative adverse reactions will be compared. ETHICS AND DISSEMINATION: This study has received approval from the Ethics Committee of Jiangsu Cancer Hospital on 28 September 2025 (Approval number KY-2025-149). The research findings will be published in international peer-reviewed academic journals and presented at academic conferences. TRIAL REGISTRATION NUMBER: ChiCTR2500112808.