Journal of clinical monitoring
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Randomized Controlled Trial Clinical Trial
Effects of intravenous anesthetic agents on middle cerebral artery blood flow velocity during induction of general anesthesia.
Our objective was to quantify the effects of intravenous anesthetics on values measured by or derived from transcranial Doppler sonography (TCD) during induction of general anesthesia. ⋯ Under the circumstances of our study, values derived from TCD measurements responded differently to the agents used to induce general anesthesia in nonneurosurgical patients.
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Randomized Controlled Trial Clinical Trial
EEG bispectrum predicts movement during thiopental/isoflurane anesthesia.
The objective of our study was to test the efficacy of the bispectral index (BIS) compared with spectral edge frequency (SEF), relative delta power, median frequency, and a combined univariate power spectral derivative in predicting movement to incision during isoflurane/oxygen anesthesia. ⋯ When bispectral analysis of the EEG was used to develop a retrospectively determined index, there was an association of the index with movement. Thus, it may be a useful predictor of whether patients will move in response to skin incision during anesthesia with isoflurane/oxygen.
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We have investigated the effect of measurement errors on cardiac output, calculated via three different Fick methods. In method 1, the classic O2 Fick equation is expressed in terms of oxygen uptake (VO2), arterial pulse (SaO2) and venous oximetry (SVO2) saturations. The second method, a modified CO2 Fick method, is obtained by replacing VO2 in method 1 with carbon dioxide production (VCO2) divided by the respiratory quotient. ⋯ However, the systematic error was least with method 3. Total errors (random and systematic) were comparable among the three methods. Using these numerical measurement errors, we conclude that continuous cardiac output may be calculated with comparable accuracy with each of these methods.