Anaesthesia Depth Consistency and System Performance of a Hermetic Closed-loop Anaesthesia Delivery System: A Randomized Validation Pilot Study

Total intravenous anaesthesia (TIVA) is now a preferred technique for providing general anaesthesia (GA) because of its various inherent advantages like reduced postoperative nausea and vomiting (PONV), improved quality of post-operative recovery, anti-inflammatory and antioxidant action, anti-neoplastic activity, analgesic action, and absence of greenhouse effect. The evolution and advancement in automated anaesthesia delivery systems particularly for propofol have made propofol-TIVA more efficient by removing the human interface for both rate and concentration adjustments. Automated computer-controlled closed loop anaesthesia device adjusts propofol delivery based on patient's frontal cortex electrical activity determined by bispectral index (BIS). Closed loop anaesthesia delivery system (CLADS) is an indigenously developed patented (Patent no.502/DEL/2003 \& US 9,108,013 B2) computer-controlled anaesthesia delivery system which works with feedback loop information elicited by BIS monitoring and delivers propofol TIVA to the patient via a non-TCI automated infusion pump. It has been an extensively used and validated in patients undergoing both cardiac and non-cardiac surgical procedures. A new compact and upgraded version of CLADS is now available. This new version incorporates the anesthetic depth monitor, hemodynamic monitor, controller, user interface and actuator syringe pump into a single, compact and user-friendly module. The investigators aim to conduct a prospective randomized pilot study comparing the new CLADS and older CLADS version with respect to: adequacy of anaesthesia depth maintenance, performance characteristic of propofol delivery system, propofol requirement, haemodynamics stability, recovery from anesthesia and postoperative sedation.