156 patients of American Society of Anesthesiologists (ASA) physical status I and II were assigned to three groups. The patients were all on schedule for elective general surgery under general anesthesia with duration of at two to four hours. All patients were induced with Etomidate (0.2mg/kg), Midazolam (0.05-0.1mg/kg), Sufentanil (0.3-0.5µg/kg) and a bolus dose of Cisatracurium (0.15mg/kg). Patients were aged between 20 and 65. The maintenance of anesthesia in each group varies as follows: Patients in Group 1 were all maintained with Total Intravenous Anesthesia, Group 2 with Sevoflurane at 1% and propofol infusion, Group 3 with only sevoflurane. Muscle paralysis is maintained using a closed-loop computer gated infusion of Cisatracurium which kept T1 <1% by giving increasing the infusion rate intra-operatively when required. Analgesia was maintained by intermittent bolus dose of 10-20 µg of Sufentanil.