Endotracheal tube (ETT) is the gold standard conduit for providing controlled ventilation during general anaesthesia (GA). however, the supra-glottic airway (SGA) devices in particular the laryngeal mask airway (LMA) and its variants have become a reliable alternative to ETT for carrying out controlled ventilation. Of the several variants of LMA available today, the proseal LMA (PLMA) is preferred for controlled ventilation. The various advantages of LMA includes, a lower incidence of postoperative sore throat and superior haemodynamic profile during surgery. However, one aspect of providing anaesthesia with LMA compared to ETT is the ability of LMA to maintain equivalent depth of anaesthesia with lower anaesthetic requirement, is quiet intriguing and evidence to this regard is very limited. By measuring the anaesthesia requirement using a robust computerised delivery system such as the closed loop anaesthesia delivery system (CLADS) we can establish for sure the anaesthesia required for maintaining intraoperative mechanical ventilation with the use of these two (ETT and PLMA) airway management devices. This randomised controlled study aims to calculate the anaesthesia requirement as determined by the total amount of propofol consumed for maintaining anaesthesia with ETT versus PLMA