Transauricular Vagus Nerve Stimulation for Postoperative Analgesia following Arthroscopic Shoulder Surgery: A Double-Blind, Randomized, Placebo-Controlled Trial

Despite growing interest in non-pharmacological analgesia, clinical evidence supporting transauricular vagus nerve stimulation (taVNS) for postoperative pain management following arthroscopic shoulder surgery remains limited. This study aimed to evaluate the efficacy and safety of taVNS in postoperative analgesia after shoulder arthroscopy. Seventy patients scheduled for arthroscopic shoulder surgery were randomly assigned to two groups on the basis fo computer-generated concealed allocation sequences. The intervention group received taVNS once on the day of surgery and once daily for the following two consecutive days, with each session lasting 2 h. The control group received sham stimulation following an identical schedule. The primary outcome was total sufentanil consumption within 24 h postoperatively. Postoperative sufentanil consumption at 24 and 48 h, resting Numeric Rating Scale (NRS) scores at 4, 6, 12, 24, and 48 h, and the requirement for rescue analgesia were all significantly lower in the taVNS group compared with the sham stimulation group (all P < 0.05). In addition, quality of recovery-15 (QoR-15) scores at 24, 48, and 72 h post surgery were significantly higher in the taVNS group (all P < 0.05). No significant intergroup differences were observed in hemodynamic parameters (all P > 0.05). The incidences of nausea, vomiting, constipation, and gastrointestinal dysmotility were lower in the taVNS group, while other adverse events did not differ significantly between groups. TaVNS demonstrates both safety and efficacy in the management of postoperative pain following shoulder arthroscopy. Its application is associated with a reduction in analgesic requirements and contributes to an improved quality of recovery during the early postoperative period. ClinicalTrials.gov identifier no. ChiCTR2400094087.