Opioid-free versus opioid-based anaesthesia and analgesia for patients at low risk for acute postoperative pain undergoing laparoscopic surgery : A randomised controlled trial

Abstract

OBJECTIVE: To evaluate if opioid-free anaesthesia (OFA), is non-inferior to standard of care (SOC), in patients at low risk for acute postoperative pain (APOP).DESIGN: Patient- and assessor-blinded, non-inferiority, randomised, controlled trial.SETTING: Single centre between March 2022 to February 2024.PATIENTS: 154 adult patients, ASA I - II, planned for elective laparoscopic surgery and risk-classified as low risk for APOP based on perceived pain during venous cannulation (VAS < 2.0).INTERVENTION: Patients were randomised to receiving OFA, including sevoflurane, dexmedetomidine, esketamine and lidocaine, or standard of care (SOC), a traditional GABAA and opioid-based strategy. Patients were subjected to the intervention from time to arrival at the day of surgery until discharge from the PACU.MEASUREMENTS: Primary outcome: worst pain intensity in the PACU.SECONDARY OUTCOMES: worst pain, and proportion having NRS ≥ 4, at 24 h (during rest and movement), worst pain and proportion having NRS ≥ 1, at 3- and 6-months (during rest and movement), postoperative recovery at 24 h, PONV in the PACU and at 24 h. Rescue dose opioids in the PACU was an exploratory outcome.RESULTS: Pain scores were 4.8 in the OFA group and 4.6 in SOC group (P = 0.67). At 24 h, worst pain at rest was 5.7 vs 5.0 (P = 0.11), and during movement 5.6 vs 5.3 (P = 0.43). Proportion of patients with NRS ≥ 4 in the PACU was 66 % vs 69 % (P = 0.65) and at 24 h 76 % vs 60 % at rest (P = 0.042) and 73 % vs 69 % during movement (P = 0.65). There was no significant difference in PPOP at 3 or 6 months, either at rest (P = 0.51, P = 0.56) or movement (P = 0.72, P = 0.48), PONV (PACU: P = 0.93), at 24 h: (P = 0.52) or postoperative recovery at 24 h (99 vs 102, P = 0.44). OFA group required less rescue opioids in the PACU (3.4 mg vs 5.1 mg, P = 0.039).CONCLUSION: When individualising anaesthesia based on predicted risk for APOP, OFA is non-inferior to a traditional GABAA and opioid-based anaesthesia strategy, for patients with a low risk for APOP undergoing laparoscopic surgery. No secondary advantages, i.e. lower PONV, less PPOP, better quality of recovery, was associated with OFA