Effect of intraoperative low dose ketamine infusion on postoperative analgesia: A randomized controlled trial.

OBJECTIVE: To evaluate the effect of subanesthetic dose of ketamine on postoperative pain scores and narcotic consumption in patients undergoing abdominal surgery under general anesthesia. Study Design: Randomized, double blinded controlled trial. Place and Duration: At the Department of Anesthesia, Combined Military Hospital, Khuzdar from 1st February 2018 to 31st January 2019. Methodology: Adult patients were randomly allocated into two groups of equal size to receive either IV ketamine bolus, 0.25mg/kg followed by IV infusion, 0.15mg/kg/h (group A) or the same volume/kg of saline (group B). A visual analogue scale (VAS) was used to measure each patient's level of pain on arrival in post anesthesia care unit, at 1, 3, 6, 12, and 24 hours after surgery. Total postoperative morphine consumption and the incidence of side effects were also recorded. Results: Intraoperative low dose ketamine resulted in effective analgesia in first 12 h postoperatively, seen by low pain scores (P=<0.05). The total morphine consumption was also reduced in the ketamine group (P=<0.05). No serious psychomimetic side effects were noted in both the groups. Conclusion: Intraoperative low dose ketamine infusion should be considered as an adjunct to opioids for postoperative pain management. [ABSTRACT FROM AUTHOR]