Effect of Subanaesthetic Dose of Ketamine on Closed-Loop Controlled Propofol Consumption

INTERVENTION: Intervention1: Clads + keta: CLADS controlled propofol delivery to keep BIS in the range 40 to 60 plus ketamine infusion of 0.5 mg/kg over 30 min Control Intervention1: Propofol CLADS: CLADS controlled propofol delivery to keep BIS in the range 40 to 60 CONDITION: Health Condition 1: N29‐ Other disorders of kidney and ureter in diseases classified elsewhere Health Condition 2: N288‐ Other specified disorders of kidney and ureter Health Condition 3: N20‐N23‐ Urolithiasis PRIMARY OUTCOME: Total propofol consumption (mg/kg/h), measured from the start of maintenance anaesthesia until the end of surgeryTimepoint: Total propofol consumption (mg/kg/h), measured from the start of maintenance anaesthesia until the end of surgery SECONDARY OUTCOME: Hemodynamic variables (heart rate, blood pressure)Timepoint: Measurered every 5 minutes till the end of the surgery Incidence of adverse events related to ketamine (e.g., hypertension, tachycardia, hypersalivation)Timepoint: During the surgery and in the post anaesthesia care unit Percentage of time BIS remained within the range of 40 to 60.Timepoint: From start to end of the surgery Performance parameters of CLADS (median performance error, median absolute performance error, and wobble)Timepoint: Studied for the duration whole of surgery Visual analogue scale (VAS) for postoperative pain on a scale from 0‐100Timepoint: Studies at 1, 2 and 6 hours postoperatively INCLUSION CRITERIA: Age more than 18 years. American Society of Anesthesiologists physical status 1 to 3. Scheduled for elective laparoscopic surgeries general anesthesia. Expected surgical duration more than 60 minutes. Provision of written informed consent.