The induction, maintenance, and recovery characteristics of spinal versus general anesthesia in elderly patients

Study Objective: To compare the induction and recovery profiles of three combinations of general anesthesia when used as an alternative to spinal anesthesia for elderly patients. Design: Randomized, prospective, open-label study. Setting: Large referral hospital Patients: 100 [ASA physical status I, II, and III] patients over 60 years of age undergoing brief transurethral surgery. Interventions: In Groups Propofol-Propofol (P-P), Propofol-Isoflurane (P-I), and Propofol-Desflurane (P-D), anesthesia was induced with fentanyl (1 to 2 mu g/kg IV) and propofol (1.0 to 2.0 mg/kg IV) and maintained with 70% nitrous oxide in oxygen and either a propofol infusion (75 to 150 mu g/kg/min) or isoflurane (end-tidal 0.7% to 1.2%) or desflurane (end-tidal 1 % to 4%), respectively. After induction, a laryngeal mask airway was placed and spontaneous ventilation was maintained. In Group Spinal (S), 1.5 ml 4% lidocaine (60 mg), in an equal volume of 10% dextrose, was administered intrathecally. Measurements and Main Results: Induction and recovery characteristics were compared. Induction with propofol was technically easier and significantly (medp < 0.0001) faster (4.6 +/- 1.7 min, 4.7 +/- 2.2 min, and 3.8 +/- 1.4 min for Groups P-P, P-I, and P-D, respectively) than induction of spinal anesthesia (9.3 +/- 3.4 min). During the induction period mean arterial blood pressure and heart rate were significantly higher in Group S. Emergence extubation, and orientation times were similar among the general anesthesia treatment groups. In Group S, patient-generated pain scores were lower (p < 0.05) and recovery room admission longer (p < 0.001). Time to return to baseline digit symbol substitution test (DSST) scores was marginally improved in Groups P-P and P-D when compared to Group P-I. Postoperative nausea, sleepiness, anxiety, and coordination were unaffected by the treatment modality. Conclusion: General anesthesia with propofol and desflurane facilitates shorter induction and recovery times without adversely affecting patient comfort. Therefore, this technique may be preferable to spinal anesthesia for elderly patients undergoing short transurethral surgical procedures. (C) 1998 by Elsevier Science Inc.