Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 2000
Prediction of the mediastinal drainage after coronary artery bypass surgery.
Using multiple correlation and linear regression approaches, we investigated the association between the amount of mediastinal drainage for the first 24 postoperative hours and clinical variables as well as multiple haematological tests performed at three time points: before anaesthesia induction, 10 minutes after protamine administration and just after skin closure, on 46 patients undergoing primary coronary artery bypass grafting. Three models from the three times were then developed to predict mediastinal drainage. ⋯ Each regression model explained approximately 60% of the variation in postoperative mediastinal drainage. The information obtained from these predictive models is useful in defining high-risk populations.
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Anaesth Intensive Care · Aug 2000
Electroencephalographic indices related to hypnosis and amnesia during propofol anaesthesia for cardioversion.
Most previous studies which have assessed the depth of anaesthesia using the Bispectral Index (BIS) have used multi-agent anaesthetics with relatively slow induction and recovery times. Elevation of electroencephalographic (EEG) Beta/Alpha Ratio has been linked to onset of midazolam amnesia. Propofol anaesthesia for cardioversion in 19 patients enabled us to profile the changes in BIS and Beta/Alpha Ratio during a short, single-agent anaesthetic with a relatively rapid induction and recovery period. ⋯ An early EEG Beta/Alpha Ratio peak occurred at a mean of 4.6 s (SD = 16.6) after clinical amnesia onset and a late peak at a mean 58 s (SD = 144) after eye opening. There was no significant EEG response to cardioversion. We conclude that: (1) in rapidly changing conditions, the value of the BIS most accurately reflects the level of consciousness of the patient about 60 s in the past, and (2) the onset and offset of propofol-induced amnesia commonly corresponds to a peak in Beta/Alpha Ratio of the EEG.
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Anaesth Intensive Care · Aug 2000
Letter Biography Historical ArticleAlexander Wood's observations on the action of opiates.