Journal of clinical monitoring
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Comparative Study
Neuromonitoring in defibrillation threshold testing. A comparison between EEG, near-infrared spectroscopy and jugular bulb oximetry.
The aim was to study the physiological effects of induced ventricular fibrillation and subsequent circulatory arrest for defibrillation threshold testing on the brain using the EEG, jugular bulb oxymetry and near-infrared spectroscopy. ⋯ Short lasting episodes of circulatory arrest have serious, but transient effects on brain function. The rSO2 is an effective non-invasive tool for monitoring cerebral oxygenation during DFT-testing.
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Current training methods in fiberoptic intubation entail a trial and error process in which trainees acquire skills by practicing this technique in mannequins or patients. These training methods are not efficient and may expose patients to unnecessary instrumentation. ⋯ The intent of this package is to simulate fiberoptic intubation techniques as well as help one create a mental image of the path a fiberscope takes within the lumen of the upper airway. The potential for improving operator immersion (virtual reality) by using a more sophisticated input device is discussed.
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A novel algorithm to detect the dicrotic notch in arterial pressure signals is proposed. Its performance is evaluated using both aortic and radial artery pressure signals, and its robustness to variations in design parameters is investigated. ⋯ The detection of the dicrotic notch in arterial pressure signals is facilitated by first calculating the arterial flow waveform from arterial pressure and a model of arterial afterload. The method is robust and reduces the problem of detecting a dubious point in a decreasing pressure signal to the detection of a well-defined minimum in a derived signal.
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A new thermodilution method for frequent (near continuous) estimation of cardiac output, without manual injection of fluid into the blood, was tested. The method utilizes a pulmonary artery catheter equipped with a fluid filled heat exchanger. The technique is based on cyclic cooling of the blood in the right atrium and measurement of the temperature changes in the pulmonary artery. ⋯ The mean coefficient of variation of repeated measurements with the near continuous thermodilution was 3.6%. Considering changes of more than 0.25 l/min to be significant, all changes in cardiac output measured by conventional thermodilution were followed by the running mean of three near continuous thermodilution estimates. This study demonstrates the feasibility of the new method to monitor cardiac output, and to detect all changes greater than 0.25 l/min.