Recovery of elderly patients from two or more hours of desflurane or sevoflurane anaesthesia.

BACKGROUND: The solubility of desflurane compared with sevoflurane suggests more rapid recovery from desflurane anaesthesia. This could be important after prolonged anaesthesia and fast recovery may be advantageous in the elderly where slow recovery of mental function is a concern. We compared emergence from desflurane vs sevoflurane in elderly patients undergoing two or more hours of anaesthesia.

METHODS: Fifty ASA physical status I, II, or III patients, 65 yr of age or older, undergoing anaesthesia expected to last two or more hours were randomly assigned to receive desflurane/nitrous oxide or sevoflurane/nitrous oxide anaesthesia. Patients were given 1-2 microg x kg(-1) fentanyl i.v. and anaesthesia was induced with propofol 1.5-2.5 mg x kg(-1) i.v. and maintained with either desflurane 2-6% or sevoflurane 0.6-1.75% with nitrous oxide 65% in oxygen. Inspired anaesthetic concentrations were adjusted to obtain adequate surgical anaesthesia and to maintain mean arterial pressure within 20% of baseline values. Early and intermediate recovery times were recorded. Digit-Symbol Substitution Test (DSST) scores and Visual Analog Scale (VAS) scores for pain and nausea were recorded before pre-medication and every 15 min in the Post Anaesthesia Care Unit (PACU) until patients were discharged.

RESULTS: Early recovery times are given as median, quartiles. The times to extubation (5 (4-9); 9 (5-13) min), eye opening (5 (3-5); 11 (8-16) min), squeezing fingers on command (7 (4-9); 12 (8-17) min); and orientation (7 (5-9); 16 (10-21) min) were significantly less (P<0.05) for desflurane than for sevoflurane. Intermediate recovery, as measured by the DSST and time to ready for discharge from the PACU (56 (35-81); 71 (61-81) min) was similar in the two groups.

CONCLUSIONS: Early but not intermediate recovery times of elderly patients undergoing a wide range of surgical procedures requiring two or more hours of anaesthesia is significantly (P<or=0.05) faster after desflurane.