Effect of transcutaneous auricular vagus nerve stimulation on postoperative pain in patients undergoing thoracoscopic partial lung resection: a randomized, double-blind, controlled clinical trial.
BACKGROUND: Postoperative pain after thoracic surgery remains common and challenging. Transcutaneous auricular vagus nerve stimulation (taVNS) is a noninvasive neuromodulation technique with potential analgesic effects. This study aimed to evaluate the efficacy and safety of taVNS for postoperative pain management in patients undergoing thoracoscopic partial lung resection. METHODS: Adults undergoing thoracoscopic partial lung resection were randomized to active or sham taVNS. The primary outcome was cough pain intensity at 48h post-surgery, assessed by Numeric Rating Scale (NRS). Secondary outcomes included cough pain at 24h and 72h, resting pain, moderate-to-severe pain incidence, opioid consumption, quality of recovery, postoperative pulmonary complications , chest tube duration, hospital stay, postoperative nausea/vomiting, and adverse events. RESULTS: Among 119 analyzed patients (active n = 60, sham n = 59), active taVNS reduced cough pain scores at 24h, 48h, and 72h postoperatively, as well as resting pain (p < 0.05). It also lowered the incidence of moderate-to-severe cough pain at 24h and 48h, reduced cumulative postoperative opioid use at 24h and 72h, and decreased rescue analgesia on postoperative day 3 (p < 0.05). Active taVNS was associated with a lower incidence of postoperative pneumothorax (p < 0.05). No serious adverse events occurred. CONCLUSION: Perioperative taVNS was associated with a modest analgesic benefit and reduced postoperative opioid requirements after thoracoscopic partial lung resection. The observed reduction in postoperative pneumothorax requires cautious interpretation, and further multicenter trials are needed to determine its clinical utility.