The Effect of Liposomal Bupivacaine Erector Spinae Plane Block

This is a single-center, randomized, controlled, double-blind clinical trial. A total of 148 patients undergoing elective open upper abdominal surgery will be included and randomly assigned 1:1 to receive ultrasound-guided erector spinae plane block with liposome bupivacaine plus bupivacaine hydrochloride or bupivacaine hydrochloride alone. The primary outcome is the AUC of resting pain scores from 0 to 72 hours postoperatively. This study aims to evaluate the analgesic efficacy and safety of liposome bupivacaine and provide a long-acting and safe postoperative analgesia strategy.