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

Background. The solubility of desflurane compared with sevofluranesuggests more rapid recovery from desflurane anaesthesia. Thiscould be important after prolonged anaesthesia and fast recoverymay be advantageous in the elderly where slow recovery of mentalfunction is a concern. We compared emergence from desfluranevs sevoflurane in elderly patients undergoing two or more hoursof anaesthesia. Methods. Fifty ASA physical status I, II, or III patients, 65yr of age or older, undergoing anaesthesia expected to lasttwo or more hours were randomly assigned to receive desflurane/nitrousoxide or sevoflurane/nitrous oxide anaesthesia. Patients weregiven 1–2 µg kg^–1 fentanyl i.v. and anaesthesiawas induced with propofol 1.5–2.5 mg kg^–1 i.v. andmaintained with either desflurane 2–6% or sevoflurane0.6–1.75% with nitrous oxide 65% in oxygen. Inspired anaestheticconcentrations were adjusted to obtain adequate surgical anaesthesiaand to maintain mean arterial pressure within 20% of baselinevalues. Early and intermediate recovery times were recorded.Digit-Symbol Substitution Test (DSST) scores and Visual AnalogScale (VAS) scores for pain and nausea were recorded beforepre-medication and every 15 min in the Post Anaesthesia CareUnit (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), squeezingfingers on command (7 (4–9); 12 (8–17) min); andorientation (7 (5–9); 16 (10–21) min) were significantlyless (P<0.05) for desflurane than for sevoflurane. Intermediaterecovery, as measured by the DSST and time to ready for dischargefrom the PACU (56 (35–81); 71 (61–81) min) was similarin the two groups. Conclusions. Early but not intermediate recovery times of elderlypatients undergoing a wide range of surgical procedures requiringtwo or more hours of anaesthesia is significantly (P