Upsala journal of medical sciences
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Comparative Study
A comparison of auditory evoked potentials and spectral EEG in the ability to detect marked sevoflurane concentration alterations and clinical events.
Level of consciousness monitors can distinguish between consciousness and unconsciousness during anaesthesia induction and awakening. However, this distinction is rarely a clinical problem. What we do need is a peroperative indicator signalling when the anaesthetic depth comes close to awakening, or when it is too deep. We investigated the ability of the Alaris fast extracted AEP (AAI) and the GE Healthcare Spectral Entropy algorithms State- and Response Entropy (SE/RE) to respond to marked changes in sevoflurane concentration during stable surgery and to clinical incidents. ⋯ The Spectral EEG monitor performed significantly better, with a larger number of events detected, compared with the AAI-monitor. However, at the best half the number of events was detected. An anaesthetic ceiling effect might to some part explain this finding. Notwithstanding, continuous anaesthetic depth monitoring may add information to low sensitive semi-continuous standard autonomic monitoring.