[Induction and maintenance of anesthesia with propofol and with thiopental-isoflurane. Comparative study]

Thirty one patients of both sexes, ASA I-II, aged 18-65 years have undergone a randomized trial in order to compare two anesthetic techniques. Patients in group I (n = 15) received a 2.5 mg/kg induction dose of propofol followed by a continuous infusion of the same drug at 3.6-9 mg/kg/h. Patients in group II (n = 16) were induced with 4 mg/kg thiopentone and maintained with 0.5-1.5% isoflurane. Both groups were evaluated for time and quality of induction, collateral effects, quality and hemodynamic stability during maintenance and time and quality of recovery. Induction time for patients in group I (49.6 +/- 15 seg) was significantly longer than for group II patients (23 +/- 3 seg) (p less than 0.01). Respiratory depression (apnea period longer than 20 seconds) was also commoner and longer in group I (p less than 0.01) although no problems were observed with manual ventilation. One patient in group I required an extra dose for induction. Both groups had similar hemodynamic changes along the procedure. Awakening time for patients in group I (24.2 +/- 7.3 min) was significantly longer than for patients in group II (14.3 +/- 4.4 min) (p less than 0.001). Although surgery times were longer in group I, a possible cumulative effect of propofol for infusions over 90 min cannot be discarded.