Comparison between opioid-free anaesthesia and opioid-based anaesthesia for laparoscopic tubal ligation- A non-inferiority randomized double-blind controlled trial

Opioids are frequently utilized under anaesthesia; however, they are associated with side effects that includes nausea, vomiting, hypotension, respiratory depression/apnoea, bradycardia, somnolence, urinary retention, and constipation, cancer recurrence etc. In recent years, the concept of opioid-free anaesthesia (OFA) has emerged. Opioid-free anaesthesia has been found to be as efficacious as conventional opioid-based anaesthesia (OBA) in terms of decreased incidence of PONV and pain management. Laparoscopic tubal ligation is a common day care laparoscopic gynaecological procedure where OFA protocol may be of greater benefit as these patients are discharged on the same day and avoiding opioids related adverse events with the use of OFA protocol may significantly improve QoR in these patients.  Hence this study has been designed with the aim to evaluate and compare the efficacy of OFA and OBA in day care laparoscopic tubal ligation. Patients will be randomly allocated into one of the two groups. Group OB will receive GA using IV fentanyl under standard institutional protocol and Group OF will   group will receive magnesium sulphate 40mg/kg in 100 ml of saline over 15 minutes (without exceeding 2.5gm) before induction of anaesthesia and inj. dexamethasone o.1 mg/kg after induction of anaesthesia. The primary outcome is AUC- NRS Pain score in 24 hours. The secondary outcomes are Pain intensity using NRS Pain at Rest (NRS-R) and Movement (NRS-M) at 0-3h, 3-6 h, 6- 12 h, 12 -24 h, Rescue analgesic consumption in the first 24 h, PONV score at 0-3h, 3-6 h, 6-12 h and 12-24 h, Rescue antiemetic consumption in the first 24 h, Intraoperative and postoperative haemodynamic, Time to Aldrete score ≥ 9, Quality of Recovery (QoR-15) score, and adverse events like constipation, urinary retention, nausea, vomiting etc.