Faster wash-out and recovery for desflurane vs sevoflurane in morbidly obese patients when no premedication is used.

BACKGROUND The aim of this study was to compare desflurane vs sevoflurane kinetics and dynamics in morbidly obese patients and their recovery profile when no premedication had been used. METHODS Twenty-eight unpremedicated obese patients were randomly allocated to receive either sevoflurane (n = 14) or desflurane (n = 14) as the main anaesthetic agent. After induction of anaesthesia, either sevoflurane 2% or desflurane 6% was administered for 30 min via a non-rebreathing circuit. The kinetics of sevoflurane and desflurane were determined by measuring and recording end-tidal samples during this time. The bispectral index was used to indicate the level of hypnosis. At the end of the procedure, the end-tidal concentrations of sevoflurane and desflurane were recorded during the first 5 min after stopping their administration. Time from discontinuation of the anaesthetic drugs to eye opening on verbal command, squeezing the observer's hand on command, extubation, stating their name, giving their correct date of birth, discharge from the recovery room, and duration of the surgery and anaesthesia were also recorded. RESULTS The F(A)/F(I) ratio was significantly higher in the desflurane group from the 15th to the 30th min. The wash-out phase was faster for desflurane during the total observation period. When desflurane was used, recovery was also faster. CONCLUSIONS Desflurane provides faster wash-in and wash-out than sevoflurane in morbidly obese patients, and recovery is much faster after desflurane administration when no premedication has been used.