Effect of Subanaesthetic Dose of Ketamine on Depth of Anaesthesia Consistency

Ketamine (concentration 5mg/ml) will be administered at 0.05-ml/kg over 5-minutes followed by continuous intraoperative ketamine infusion of 0.05-ml/kg /h.

Propofol administration rate will be controlled by a feedback loop facilitated by BIS monitoring using the conventional closed loop anaesthesia delivery system (CLADS). A BIS value of 50 will be used as the target point for induction and maintenance of anaesthesia.

Normal saline bolus 0.05-ml/kg will be administered over 5-minutes and it will be followed by continuous intraoperative normal saline infusion at 0.05-ml/kg /h.