Abstract
BACKGROUND: Liposomal bupivacaine provides prolonged analgesia, but evidence for its efficacy in anterior quadratus lumborum block (QLB) for laparoscopic gynecological surgery remains limited. This study compared liposomal bupivacaine combined with bupivacaine (LB) versus bupivacaine combined with dexamethasone (BD). METHODS: In this randomized controlled trial, 136 patients undergoing laparoscopic hysterectomy or myomectomy were randomized to receive anterior QLB with either LB or BD. The primary outcome was cumulative oxycodone consumption within 48 h postoperatively. Secondary outcomes included oxycodone use across predefined postoperative intervals, resting and cough numerical rating scale (NRS) pain scores, pain area under the curve (AUC), opioid-free proportion within 72 h, duration of analgesia, and postoperative adverse events. RESULTS: 67 LB and 69 BD patients completed the study. Cumulative 48-h oxycodone consumption was comparable between the two groups (1 mg [0-3] vs. 2 mg [0-6], P = 0.192; median difference 0 mg, 95% CI -2 to 0 mg). Oxycodone use across 0-12, 0-24, 0-48, 48-72, and 0-72 h did not differ significantly. Although the LB group showed statistically lower oxycodone use during the 12-24 and 24-48 h periods, median values were 0 mg in both groups. Resting and cough NRS scores and 72-h pain AUC were similar between the two groups. Approximately 45% of patients remained opioid-free during the first 72 h after surgery in both groups. The duration of analgesia was significantly longer in the BD group (1,553 vs. 561 minutes, P < 0.001). Adverse event rates were low and comparable. CONCLUSION: Liposomal bupivacaine combined with bupivacaine did not reduce opioid consumption or improve analgesic outcomes compared with bupivacaine-dexamethasone for anterior QLB in laparoscopic gynecological surgery. Both regimens provided effective and well-tolerated analgesia. TRIAL REGISTRATION: Chinese Clinical Trials Registry Platform (chictr.org.cn): ChiCTR2500096893.