[The use of propofol in combination with fentanyl or buprenorphine in long-duration anesthesia].

Fifty patients of both sexes, aged between 37 and 60 years old and belonging to ASA classes I, II, III and IV, underwent urological surgery lasting more than two hours under general anesthesia using a continuous infusion of propofol, N2O/O2, vecuronium bromide 0.02% infusion. Patients were divided into two groups of 25, group A and group B, according to whether they received fentanyl or buprenorphine as an analgesic. Propofol and fentanyl consumption in group A were 5.43 +/- 0.7 mg/kg/hour and 10.53 +/- 1.7 micrograms/kg respectively, whereas those of propofol and buprenorphine in group B were 5.71 +/- 1.08 mg/kg/hour and 6.05 +/- 0.06 micrograms/kg; there was a statistically non-significant difference for propofol consumption (p greater than 0.005). During the induction and maintenance phases of anesthesia, hemodynamic parameters decreased significantly (p less than 0.001) in comparison to starting values in both groups, but no statistically significant differences were observed. Buprenorphine prolonged reawakening from anesthesia by a few minutes but at the same time extended postoperative analgesia by several hours, thus improving the overall quality of the immediate postoperative period. The most frequent side effect (32% in group A and 52% in group B) was sinusal bradycardia.