Peri-operative use of ketamine infusion versus dexmedetomidine infusion for analgesia in obese patients undergoing bariatric surgery: A double-blinded three-armed randomized controlled trial

Background: The development of different techniques in bariatric surgeries has required the development of novel anesthetic techniques to reduce the incidence of complications and improve post-operative patient outcomes. Ketamine and dexmedetomidine have been used for their peri-operative analgesic profiles in different studies. Methods: : Ninety patients were studied and randomized equally into three groups. The Ketamine group received a bolus dose (0.3 mg/kg) of ketamine over 10 min followed by an infusion (0.3 mg/kg/h). The Dexmedetomidine group received a bolus dose (0.5 mcg/kg) of dexmedetomidine over 10 min followed by an infusion (0.5 mcg/kg/h). The control group received normal saline infusion. The total morphine dose was the primary outcome ,and intra-operative fentanyl requirements, time to extubation, post-operative nausea and vomiting (PONV), Numerical Rating Scale (NRS) scores, and Modified Observer’s Agitation/Sedation Scale (MOASS) scores were secondary outcomes of the study. Results: : The Dexmedetomidine group showed decreased intra-operative fentanyl requirements (160.000 ± 42.345 µcg), less time to extubation (3.700 ± 0.925 min), and better scores on MOASS than the other groups. Post-operative NRS scores and the morphine requirement in the Ketamine group (1.867 ± 2.921 mg) were lower than in the other groups. The Dexmedetomidine group showed the lowest scores for PONV. Conclusions: : The Dexmedetomidine group showed lower total fentanyl doses, a significantly shorter time to extubation, better MOASS scores, and lower PONV. The Ketamine group showed significantly lower NRS scores and morphine doses than the other two groups. Dexmedetomidine was effective on the reduction of intraoperative fentanyl requirement with early extubation, and ketamine was effective on the reduction of postoperative pain. Trial Registration: this trail has been registered on clinicaltrials.gov registry (NCT04576975) since 06/10/2020