Opioid free versus opioid based anesthesia in abdominal gynecological surgery: a prospective randomized controlled trial

Background & objective: Opioids have been in use by the anesthesiologists in almost all major surgical cases since ages, but these are not without side effects. During the recent past, opioid free anesthesia-a wonderful technique, has gained rapid popularity as it saves the patient from the side effects. Many drugs and drug combinations have been advocated. Ketamine-lidocaine combination produces central desensitization of the pain pathways, and an anti-inflammatory and anti-hyperalgesic effect in a synergistic manner. We compared opioid free versus opioid based anesthesia in abdominal gynecological surgery regarding analgesic efficacy and the side effects. Methodology: After trial registration (PACTR202007844671903), 68 patients enrolled in this study were divided into two groups (34 each) according to the analgesics used. Under GA, Group O received loading dose of fentanyl 1 mu g/kg followed by infusion at a rate of 1 mu g/kg/h. Group OF received ketamine 0.5 mg/kg as a bolus, a loading dose of lidocaine 1.5 mg/kg followed by infusion 1.5 mg/kg/h. The primary outcome objective was postoperative pain assessed for 24 h using VAS score. Results: The VAS score was significantly lower in Group OF during the first 4 postoperative hours; at immediate postoperative time-VAS0 (p 0.001), after one hour-VAS1 (p 0.001), 2h after-VAS2 (p = 0.001), and 4 h after-VAS4 (p = 0.001). Also, Group OF showed significantly lower recovery time (p = 0.001), higher RASS score (p = 0.001), less rescue analgesic consumption, no bowel dysfunction with stable peri-operative hemodynamics. Conclusion: Opioid free anesthesia is a promising technique, using ketamine-lidocaine combination in abdominal gynecological surgeries enhanced patients recovery with better analgesia profile and stable hemodynamics. Abbreviations: HR-heart rate; MABP-mean arterial blood pressure; NIBP-non-invasive blood pressure; NMDA-Nmethyl D-aspartate; NSAIDs-non steroidal anti-inflammatory drugs; OFA-opioid free anesthesia; PACU-post anesthesia care unite; RASS-Richmond agitation sedation score; RR-respiratory rate; VAS-visual analogue score; VCV-volume controlled ventilation