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 co mbinations of general anesthesia when used as an alternative to spinal anes thesia 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 surge ry. 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% n itrous oxide in oxygen and either a propofol infusion (75 to 150 mu g/kg/mi n) 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 s pontaneous ventilation was maintained. In Group Spinal (S), 1.5 ml 4% lidoc aine (60 mg), in an equal volume of 10% dextrose, was administered intrathe cally. 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 m in for Groups P-P, P-I, and P-D, respectively) than induction of spinal ane sthesia (9.3 +/- 3.4 min). During the induction period mean arterial blood pressure and heart rate were significantly higher in Group S. Emergence ext ubation, and orientation times were similar among the general anesthesia tr eatment 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 base line digit symbol substitution test (DSST) scores was marginally improved i n Groups P-P and P-D when compared to Group P-I. Postoperative nausea, slee piness, anxiety, and coordination were unaffected by the treatment modality . Conclusion: General anesthesia with propofol and desflurane facilitates sho rter induction and recovery times without adversely affecting patient comfo rt. Therefore, this technique may be preferable to spinal anesthesia for el derly patients undergoing short transurethral surgical procedures. (C) 1998 by Elsevier Science Inc.