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Monitoring depth of anaesthesia

Schneider, G.; Sebel, P. S.

European Journal of Anaesthesiology: May 1997 - Volume 14 - Issue - pp 21-28
Update in Intravenous Anaesthesia: Original Papers

In clinical practice, indirect and non-specific signs are used for monitoring anaesthetic adequacy. These include haemodynamic, respiratory, muscular and autonomic signs. These measures do not indicate adequacy of anaesthesia in a reliable manner. Many attempts have been made to find a more accurate monitor. Direct monitoring of anaesthetic effect should be possible by EEG measurement. EEG information can be reduced, condensed and simplified, leading to single numbers (spectral edge frequency and median frequency). These methods appear insufficient for assessing anaesthetic adequacy. The bispectral index, derived from bispectral analysis of the EEG, is a very promising tool for measuring adequacy of anaesthesia. An alternative approach is to monitor evoked potentials. Middle latency auditory evoked potentials may be helpful in assessing anaesthetic adequacy. Both techniques need further validation.

Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA

Correspondence to: Professor Peter S. Sebel, Department of Anesthesiology - Box 26074, Grady Health System, 80 Butler Street, SE, Atlanta, Georgia 30335-3801, USA.

© 1997 European Society of Anaesthesiology