The Effect of Low Dose Intra-operative Ketamine on Closed-loop Controlled General Anesthesia

"Once IV access has been obtained and a facemask has been applied for pre-oxygenation, the loading dose (0.25 mg/kg) of the study drug will be given over 60 seconds and the fixed infusion (5 mcg/kg/min to a maximum of 60 mg/hour) will be initiated by the anesthetist through the pump interface.~The study drug will be infused at a constant rate of 5 mcg/kg/min throughout the maintenance phase, until the end of the procedure (last suture), up to a maximum cumulative dose of 100 mg. If at any point the anesthesiologist feels that it is clinically necessary to reduce the amount of study drug infusion rate, they may opt to reduce the infusion rate by 50% (to 2.5 mcg/kg/min), or stop the infusion entirely."

Participants in the control group will receive an equivalent volume bolus and infusion of normal saline to mimic the ketamine infusion in the ketamine group.