A Prospective Comparative Study of Opioid-Free Anesthesia and Opioid-Based Anesthesia for Postoperative Pain Relief in Patients Undergoing Laparoscopic Surgeries: A Double-Blinded Randomized Controlled Trial

Background: Opioid-based anesthesia (OBA) is widely used for laparoscopic surgery but may be associated with opioid-related adverse effects, including postoperative nausea and vomiting (PONV), respiratory depression, pruritus, and delayed recovery.This study aimed to evaluate the effectiveness and safety of opioid-free anesthesia (OFA) compared with OBA in patients undergoing elective laparoscopic surgery, with postoperative pain assessed as the primary outcome.Methods: This double-blind, randomized controlled trial was conducted in the Department of Anesthesiology at Shri Sathya Sai Medical College and Research Institute, Chengalpattu, India.Sixty-two adults undergoing elective laparoscopic surgery were randomly allocated to OFA (n = 31) or OBA (n = 31).Postoperative pain was assessed using the Visual Analog Scale (VAS) at 2, 6, 12, 24, and 48 hours.Secondary outcomes included rescue analgesia, perioperative hemodynamic parameters, PONV, and other postoperative adverse events.Results: Baseline demographic and clinical characteristics were comparable between the groups.VAS scores were significantly lower with OFA at six hours (3.2 ± 0.8 vs. 4.6 ± 1.2; Holm-adjusted p < 0.001), 12 hours (3.2 ± 0.9 vs. 4.0 ± 0.8; p = 0.004), and 24 hours (3.0 ± 0.6 vs. 3.4 ± 0.4; p = 0.009), whereas scores at 2 and 48 hours were comparable.Rescue analgesia within six hours was required by one patient (3.2%) in the OFA group and six patients (19.4%) in the OBA group (Fisher's exact p = 0.104).Among participants with a recorded rescueanalgesia event, the reported mean time to first rescue analgesia was longer with OFA (8.7 ± 1.9 vs. 7.0 ± 1.7 hours; p < 0.001).Heart rate and systolic blood pressure were comparable between the groups, while diastolic blood pressure and mean arterial pressure were higher with OFA at six hours postoperatively.PONV at six hours and overall complications were less frequent with OFA.Conclusions: OFA was associated with improved early postoperative analgesia, with lower VAS scores at 6, 12, and 24 hours following elective laparoscopic surgery.Although rescue analgesia within six hours was numerically less frequent with OFA, the difference was not statistically significant.OFA was also associated with lower PONV at six hours and fewer overall complications.Perioperative hemodynamic parameters were broadly comparable, with modest differences in diastolic blood pressure and mean arterial pressure at six hours.Larger multicenter randomized trials are warranted to confirm these findings.