In this group patients were aged from 20 to 45. Propofol infusion was used to maintain Bispectral Index (BIS) between 45 and 55.

Intermittent doses of sufentanil 10-20 microgram were given intra-operatively on a required basis.

In this group patients were aged from 46 to 65. Propofol infusion was used to maintain Bispectral Index (BIS) between 45 and 55.

Intermittent doses of sufentanil 10-20 microgram were given intra-operatively on a required basis.

In this group patients were aged from 66 to 85. Propofol infusion was used to maintain Bispectral Index (BIS) between 45 and 55.

Intermittent doses of sufentanil 10-20 microgram were given intra-operatively on a required basis.

In this group patients were aged from 46to 65. Propofol infusion was used to maintain Bispectral Index (BIS) between 45 and 55.

Dexmedetomidine infusion is started at induction,a bolus dose of 0.5 µg/kg is given over the first hour which is followed by infusion of 0.4 µg/kg/hr.

Intermittent doses of sufentanil 10-20 microgram were given intra-operatively on a required basis.

In this intervention we compared the cisatracurium consumption, recovery index and sufentanil consumption between P2 and D. The reason we are comparing patients in group D with P2 is that because they belong to the same age group.

Measurements were done during the operation. Cisatracurium infusion was controlled a closed loop computer system. The degree of neuromuscular blockage was assessed every 20 seconds throughout the procedure using the train of four testing. It was done by counting the number and amplitude of twitches evoked after electrical stimulus and the rate of infusion maintained itself at the low rate of 0.20µg/kg/min as long as the T1 response is less than 1%. When the T1 > 1%, the rate of infusion would automatically increase to 5.0 µg/kg/min until T1 < 1%, after which the infusion rate would fall back to 0.20µg/kg/min. The controlled infusion described above administered small doses of cisatracurium intra-operatively to maintain a muscle relaxation of more than 99%. The system saved the time and amount of drug given throughout the operation, from which the consumption was calculated in µg/kg/min.

Analgesia was maintained by intermittent bolus dose of 10-20 µg of Sufentanil when the pulse and blood pressure would increase by more than 20% of the baseline, and BIS in the required range, as this would indicate an increase perception of pain but adequate anaesthesia. Sufentanil consumption was calculated for each patient in µg/kg/hr and the length of the operation was determined as from induction to the time of skin closure.

Recovery Index, time for the Train-Of-Four (TOF) value to increase from 25% to 75%, was measured in each patient who completed the study. Its measurements were recorded in minutes.