Comparison of TIVA by Closed Loop Anaesthesia Delivery System Versus Target Controlled Infusion Device

Total intravenous anaesthesia (TIVA) is now being adopted as a preferred technique for providing GA because of its various inherent advantages like reduced PONV incidence, improved quality of recovery post GA, anti-inflammatory and anti-oxidant action, anti-neoplastic activity, analgesic action, and absence of greenhouse effect. Over the years propofol-TIVA delivery has become more methodical due to the use of target-controlled infusion (TCI) systems. The current TCI technology has evolved with the introduction of the 'open' TCI concept wherein syringes of any configuration can be attached to the TCI-pumps having pre-programmed propofol PK-PD models. The two most commonly use propofol PK-PD models are the Marsh and Schneider models targeting the propofol blood plasma concentration and effect site concentration in the brain respectively. Automated delivery of propofol using computer-controlled closed loop anaesthesia device delivers propofol based on patient's frontal cortex electrical activity as determined by bispectral index (BIS). Evaluation of anaesthesia delivery by these systems has shown that they deliver propofol and maintain depth of anaesthesia with far more precision as compared to manual administration. A recent advance in propofol delivery has been the development of automated closed loop anaesthesia delivery system. These devices deliver propofol based on patient's frontal cortex electrical activity as determined by bispectral index (BIS).Closed loop anaesthesia delivery system (CLADS) is an indigenously developed continuous automated intravenous infusion system which delivers propofol based on patients' EEG profile (BIS) feedback. Currently there is no data available comparing the efficacy of TCI delivered propofol versus automated propofol delivery systems. The investigators hypothesize that automated propofol delivery by CLADS will provide more consistent anaesthesia depth maintenance as compared to TCI delivered propofol. This randomized controlled