Biphasic EEG changes in relation to loss of consciousness during induction with thiopental, propofol, etomidate, midazolam or sevoflurane

摘要: The time course of four EEG effect variables, amplitude in the 2-5 Hz and 11-15 band, spectral edge frequency 95% (SEF95), bispectral index (BIS), response to increasing concentrations thiopental, propofol, etomidate, midazolam, or sevoflurane during a 10 min induction anaesthesia was studied 25 patients determine existence biphasic study relationship moment loss consciousness. A effect, that is, an initial increase variable followed by decrease at higher concentrations, transition from consciousness unconsciousness found (both bands) SEF95 for all anaesthetics except midazolam. There concentration-related BIS anaesthetics. no consistent between occurrence peak value With rapidly changing drug anaesthesia, none these variables could be correlated