Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 2000
Comparative StudyClinical evaluation of the non-invasive cardiac output (NICO) monitor in the intensive care unit.
The Non-invasive Cardiac Output (NICO) monitor (Novametrix Medical Systems Inc., Wallingford, CT, U. S. A.) utilizes a minimally-invasive partial rebreathing method to determine cardiac output by means of a differential form of the Fick equation. ⋯ Comparison of the two techniques using the method described by Bland and Altman showed decreased correlation at higher values of cardiac output. We conclude that the NICO monitor may well have a place in intensive care monitoring, provided patients are not breathing spontaneously and are able to tolerate a 4 mmHg rise in PaCO2. It is less suitable for use in patients with a high cardiac output state.
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Anaesth Intensive Care · Aug 2000
Case ReportsSwelling and cyanosis of the tongue associated with use of a laryngeal mask airway.
We present a case report of a patient who developed acute swelling of the tongue during anaesthesia using the laryngeal mask airway. The swelling was thought to be due to obstruction of the venous drainage of the tongue. ⋯ The swelling and cyanosis of the tongue resolved rapidly after removal of the laryngeal mask airway. The patient suffered paraesthesia of the tip of the tongue that lasted for two weeks.
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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.