Objective: The depth of sedation produced by 3 different infusion doses of propofol was compared by means of Observer Assessment of Alertness and Sedation Scores(OAA/S) and Bispektral Indeks (BIS) during spinal anesthesia.

Materials and methods: With the permission of hospital ethics committee, 18-60 year old 60 patients in ASA I-III who would undergo spinal anesthesia were divided into 3 groups, randomly. Following spinal anesthesia, 1mg.kg-1 propofol bolus was given to all patients intravenously and then, a continuous infusion of propofol, 3mg.kg-1.h-1 in GroupI, 4mg.kg-1.h-1 in GroupII and 5mg.kg-1.h-1 in GroupIII were started. Heart rate(HR), mean arterial pressure(MAP), perypheral oxygen saturation(SpO2), respiration rate(RR), BIS, OAA/S were recorded before propofol infusion and during 45min. with intervals of 5min after infusion. Side effects and complications were observed during infusion.

Results: OAA/S and BIS were significantly lower than basal values at all measurements in all groups. In GroupI, OAA/S was significantly higher at 20thmin than the other groups. In GroupIII, OAA/S at 15th min was lower than the other groups. Even the decreases at HR, MAP, RR and SpO2 were observed, there had been no important cardiovascular or ventilatory depression requiring either to stop infusion or urgent therapy.

Conclusion: Considering OAA/S values, 3mg.kg-1.h-1 propofol dose was found to reach the optimum sedation level in the highest ratio without any adverse effects. Besides, 4 and 5mg.kg-1.h-1 dose of propofol maintained deeper sedation without any adverse effects.©2006, Fırat Üniversitesi, Tıp Fakültesi