Effect of opioid-free anesthesia on postoperative recovery in elderly patients undergoing laparoscopic abdominal surgery: a randomized controlled trial

Abstract

Background Opioid-free anesthesia (OFA) has been proposed to reduce opioid-related adverse effects, although its impact on overall postoperative recovery remains uncertain. We evaluated whether OFA improves postoperative quality of recovery compared with opioid-based anesthesia (OA) in elderly patients undergoing laparoscopic abdominal surgery. Methods In this single-center randomized controlled trial, 200 patients aged ≥60 years undergoing elective laparoscopic abdominal surgery were randomized to receive either OFA (dexmedetomidine, esketamine, and lidocaine) or conventional OA. The primary outcome was quality of recovery measured using the QoR-15 questionnaire at 24 h after surgery. Secondary outcomes included postoperative nausea and vomiting (PONV), pain scores, opioid consumption, gastrointestinal recovery, sleep quality, chronic postsurgical pain, hemodynamic events, extubation time, PACU length of stay, and hospital length of stay. Results A total of 195 patients completed the study (OFA, n = 98; OA, n = 97). QoR-15 scores at 24 h were higher in the OFA group (110 ± 12 vs. 106 ± 15, mean difference 4 points, 95% CI 2–8; p = 0.002). However, the observed difference was below the prespecified threshold for clinical significance and was no longer present at 48 or 72 h. OFA reduced the incidence of PONV during the first 72 postoperative hours and modestly reduced postoperative opioid consumption. Gastrointestinal recovery occurred earlier with OFA, whereas pain scores were largely similar between groups except during the immediate PACU period. OFA was associated with longer extubation times, prolonged PACU stay, and a higher incidence of intraoperative hypertension. Hospital length of stay and postoperative delirium were similar between groups. Although chronic postsurgical pain at 3 months was less frequent in the OFA group, this secondary finding should be considered exploratory. Conclusion In elderly patients undergoing laparoscopic abdominal surgery, OFA reduced postoperative nausea and vomiting and modestly accelerated gastrointestinal recovery. However, it did not result in a clinically meaningful improvement in overall postoperative recovery as measured by the QoR-15 and was associated with delayed emergence, prolonged PACU stay, and more frequent intraoperative hypertension. These findings suggest that the principal benefit of OFA in this setting may be reduction of opioid-related adverse effects rather than substantial enhancement of global postoperative recovery.