Awakening from anesthesia and recovery of cognitive function after prolonged sevoflurane, isoflurane or propofol anesthesia in elderly patients

The aim of this study was to evaluate the awakening from anesthesia and recovery of cognive function after prolongcal sevoflurane, isoflurane or propofol anesthesia in elderly patients. The study was carried out on 45 educated consented patients. ASA I-III, aged 60 years or older, of both genders, undergoing elective urologic, orthopedic or gynecological operations. Anesthesia was induced with propofol 1-2 mg/ kg. fentanyl I mg/ kg and maintained with N2O and the study drugs. Patients were randomly allocated, into 3 groups [15 each] to receive either sevoflurane 1-1.5% [group I], isoflurane 0.5-1.5% [group 2] or propofol infusion at a rate of 2-6 mg /kg/ hr [group 3]. These anesthetics were titrated to achieve adequate level of surgical anesthesia and to maintain heart rate and blood pressure within 20% of the baseline values. At the end of anesthesia, muscle relaxants were reversed, also. N2O and the study durgs were turned off suddenly without previous tapering. The following recovery times were recorded [extubation, emergence, triple orientation, response to command, first anlgesic intake and discharge from recovery room] Aldrete score and Mini-Mental State test [MMS] were used as indicators of cognitive function and measured preoperatively and at 15,30,60, 90,120 and 360 minutes from admission to recovery room Also, postoperative side effects were assessed. The results showed that sevoflurane had shorter times to extubation]8.26 +/- 0.52 vs 10.32 +/- 1.19 or 13.56 +/- 1.35 min], emergence [6.77 +/- 0.79 vs 12.4 +/- 1.58 or 11.33 +/- 1.67 min], response to command]9.53 +/- 1.29 vs 13.2 +/- 1.05 or 15.0 +/- 1.53 min] and orientation [11.86 +/- 1.23 vs 15.35 +/- 1.17 or 16.87 +/- 1.09 min] compared to propofol or isoflurane respectively [P< 0.05] The extubation time and response to command time were faster after propofol in comparison with isoflurane [P< 0.05]. The time to first analgesic intake was longer after isoflurane compared to sevoflurane or propofol [P< 0.05]. however, the discharge time from the recoveryroom was not statistically significant between the three groups. More patients in sevoflurane and propofol groups had Aldrate score A'8 at 15 and 30 min from admission to recovery room than in isoflurane one. MMS test showed a delay in the recovery of cognitive function for 30, 60 and 90 min, compared lo preoperative values, in propofol sevoflurane and isofluranc groups respectively [P<0.05]. However, there was a rapid recovery of cognitive function m sevoflurane and propofol groups compared to isoflurane one at 15, 30, 60,and 90 min [P< 0.05]. The side effects during recovery showed a lower incidence of nausea and vomiting in the propofol group [P< 0.05]. In conclusion, both sevoflurane and propofol are useful alternatives for maintenance of anesthesia after prolonged operations in elderly patients in terms of recovery times, return of cognitive function and side effects