Comparison of two different doses of intravenous morphine on desflurane consumption in patients undergoing total abdominal hysterectomy

Objective: this study evaluates the effects of two different doses of morphine used at anesthesia induction on desflurane consumption,extubation and recovery times,hemodynamic variables and postoperative analgesic requirements during abdominal hysterectomy. method: ninety patients,scheduled for elective abdominal hysterectomy were randomly allocated into three groups. after induction of anesthesia,patients in group s (n=30) received 10 ml saline,group ml (n=30) received 0.1 mg kg-1 morphine and group m2 (n=30) received 0.2 mg kg-1 morphine in 10 ml volume intravenously. anesthesia was maintained with desflurane 6% in a mixture of 33% oxygen and 67% nitrous oxide. the depth of anesthesia was monitorized with bispectral index (bis). bis lewis were kept within 40-60 by changing the concentration of desflurane by 1%. desflurane concentrations and consumption,time to extubation and recovery,hemodynamic variables,postoperative pain scores and supplement analgesic consumption were recorded. results: compared with saline group,bis values were significantly lower in the both morphine groups (p < 0.001). desflurane consumption was significantly lower in both morphine groups (72.75 ml in group s,48.22 ml in group m1 and 15.53 ml in group m2),(p < 0.01). the extubation times were similar but recovery times were longer in the morphine groups (p < 0.001). mean arterial pressure,heart rate variables were higher in group s than the other groups (p < 0.01). postoperative analgesic requirements were higher in group s than in morphine groups (p < 0.01),while more supplemental analgesic were required in the low dose morphine group than in high dose morphine group (p < 0.01). conclusion: in this study,it was concluded that two different doses of intravenous morphine used at anesthesia induction significantly decreased the consumption of desflurane with increased time to recovery without changing time to extubation,and provided effective analgesia with stable hemodynamics in patients undergoing total abdominal hysterectomy.