Effect of transcutaneous auricular vagus nerve stimulation on perioperative anxiety in patients undergoing radical mastectomy: study protocol for a randomized controlled clinical trial

Background: Breast cancer patients often experience significant concerns regarding surgery, which predisposes them to negative emotions such as anxiety, adversely affecting both surgical outcomes and postoperative recovery. However, research on interventions for perioperative anxiety remains limited. This study focuses on patients undergoing radical mastectomy to investigate the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on perioperative anxiety, aiming to provide novel clinical strategies for its prevention and management. Methods: This prospective, double-blind, randomized controlled trial will enroll 202 eligible patients with radical mastectomy. Patients are randomly assigned to either the treatment group (taVNS group) or the control group (sham stimulation group). In treatment group, taVNS is administered 30 min before anesthesia induction and at the same time point daily for postoperative days 1-3, using specific stimulation parameters. The control group was given a sham stimulus. Primary outcome is the perioperative anxiety remission rate, which assessed by comparing post-intervention (after the final session) and pre-intervention (before the first session) scores in patients subjected to either full-course taVNS or sham stimulation. Secondary outcomes are Hamilton Anxiety Rating Scale (HAMA), Pittsburgh Sleep Quality Index (PSQI), 3-Minute Diagnostic Interview for Confusion Assessment Method-Defined Delirium (CAM-3D), Numerical Rating Scale (NRS), Fatigue, Resistance, Ambulation, Illnesses, and Loss of Weight (FRAIL) and heart rate variability (HRV). Discussion: The strength of this study lies in the adoption of taVNS as an intervention for perioperative anxiety and the establishment of a comprehensive efficacy evaluation system. taVNS may alleviate anxiety by modulating autonomic nervous function and restoring the balance between sympathetic and parasympathetic activity. This study aims to provide an innovative approach for mitigating perioperative anxiety, with the potential to improve patient outcomes and enhance quality of life. Clinical trial registration: https://www.chictr.org.cn/indexEN.html, Identifier ChiCTR2500106867.