Effect of Dexmedetomidine on Propofol Requirement During Anesthesia

Dexmedetomidine, a selective alpha-2 agonist agent used for maintaining sedation in intensive care patients in receipt of mechanical ventilation, is being increasingly utilized in anaesthesia practice for facilitating anaesthesia depth as an adjunct to base anaesthetics (intravenous; propofol: inhalational; sevoflurane, desflurane). The investigators intend to assess the anaesthetic potential of dexmedetomidine in controlled anaesthesia settings empowered by the use of an objective, patient response based, safe, efficient, and patented closed loop anaesthesia delivery system (CLADS). CLADS functions on control of processed EEG response parameter captured from anaesthetized patients with the help of a BIS- monitor, which is continuously fed into a automated drug infusion pump. The infusion pump then accordingly delivers the anaesthetic drug to the patients based on pharmacodynamic requirements. If dexmedetomidine has anaesthesia potential then it is likely that propofol use delivered by CLADS can be reduced further. In addition the effect of two drugs (viz, base agent-propofol plus adjunct agent-dexmedetomidine) on different receptor site within the brain would help gain greater anaesthetic depth consistency as well as a lower incidence of intraoperative patient awareness. This prospective randomized two-arm study aims to assess effect of the use of dexmedetomidine on propofol requirements (primary objective), anaesthesia depth consistency, and intraoperative patient awareness (secondary objectives).