Intrapleural Bupivacaine Analgesia for Postoperative Pain Management After Minimally Invasive Video-Assisted Thoracoscopic Surgery: A Randomized Controlled Trial

Postoperative pain is common after video-assisted thoracoscopic surgery (VATS), with pleural irritation caused by chest tube placement being a major contributor. Inadequate pain control may impair respiratory function, delay postoperative recovery, and increase the risk of complications. However, effective and targeted analgesic strategies specifically addressing chest tube-related pain remain limited. This is a single-center, prospective, randomized, double-blind, placebo-controlled superiority trial designed to evaluate the efficacy and safety of programmed intermittent intrapleural administration of bupivacaine at different concentrations for postoperative analgesia after VATS. A total of 249 patients undergoing VATS will be randomly assigned in a 1:1:1 ratio to receive intrapleural injections of 0.25% bupivacaine, 0.125% bupivacaine, or normal saline. The primary outcome is pain intensity during coughing within 48 hours after surgery. Secondary outcomes include pain intensity at rest, plasma bupivacaine concentrations, quality of postoperative recovery, cumulative opioid consumption, and postoperative inflammatory marker levels. This study aims to provide evidence to inform analgesic strategies for chest tube-related pain following VATS and to clarify the optimal use and safety profile of intrapleural bupivacaine.