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

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.