Comparative analgesic effects of lidocaine-dexmedetomidine co-administration in major laparoscopic gynecologic surgery: a randomized controlled trial.
Background The intraoperative co-administration of lidocaine and dexmedetomidine has been proposed as an opioid-sparing strategy; however, its effectiveness as an intraoperative multimodal analgesia (MMA) strategy remains unclear. We evaluated its effect on postoperative opioid consumption in patients undergoing major laparoscopic gynecologic surgery. Methods We conducted a randomized controlled trial comparing intraoperative placebo with lidocaine-dexmedetomidine co-administration in patients undergoing major laparoscopic gynecologic surgery within a standardized Enhanced Recovery after Surgery (ERAS) pathway. Patients were assigned to receive intraoperative placebo or lidocaine at 1.5 mg/kg/h co-administered with dexmedetomidine at either 0.4 or 0.7 μg/kg/h. The primary outcome was 24-h cumulative opioid consumption. Results Twenty-four-hour cumulative opioid consumption differed significantly between the groups (P = 0.004). Median morphine-equivalent dose was 16.6 mg (12.1, 22.3) in the control group, 11.3 mg (8.1, 19.5) in the lidocaine-dexmedetomidine 0.4 group, and 11.1 mg (6.8, 16.5) in the 0.7 group, corresponding to relative reductions of 32% and 33% in median consumption, respectively. Both dexmedetomidine doses (0.4 and 0.7 μg/kg/h), when co-administered with lidocaine, were associated with significantly lower opioid consumption than the control group, with no significant differences between the two doses. Pain scores during mobilization were lower in both treatment groups during the first 48 h postoperatively, without an increase in adverse events. Conclusion Intraoperative co-administration of lidocaine and dexmedetomidine effectively reduced postoperative opioid consumption and pain during mobilization as an intraoperative MMA strategy within an ERAS pathway. The higher dexmedetomidine dose provided no additional opioid-sparing benefit during the first 24 postoperative hours.