Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2016
Observational StudyNear-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair: relation to end-tidal CO2 tension.
During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. ⋯ Changes in ScO2 related to those in EtCO2 (r = 0.41; P = 0.0001) and cerebral deoxygenation (-15 %) was noted in three patients while cerebral hyperoxygenation (+15 %) manifests in one patient. Thus changes in ScO2 were kept within acceptable limits (±15 %) in 91 % of the patients. For the majority of the patients undergoing AAA repair ScO2 was kept within reasonable limits by reducing ventilation by approximately 1 l min(-1) upon clamping of the aorta and increasing ventilation by approximately 2 l min(-1) when the lower body is reperfused.
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J Clin Monit Comput · Aug 2016
Comparative StudyContinuous noninvasive cardiac output determination using the CNAP system: evaluation of a cardiac output algorithm for the analysis of volume clamp method-derived pulse contour.
The CNAP system (CNSystems Medizintechnik AG, Graz, Austria) provides noninvasive continuous arterial pressure measurements by using the volume clamp method. Recently, an algorithm for the determination of cardiac output by pulse contour analysis of the arterial waveform recorded with the CNAP system became available. We evaluated the agreement of the continuous noninvasive cardiac output (CNCO) measurements by CNAP in comparison with cardiac output measurements invasively obtained using transpulmonary thermodilution (TDCO). ⋯ This pilot analysis shows that CNCO determination is feasible in critically ill patients. A percentage error of 25 % indicates acceptable agreement between CNCO-cal and TDCO. The mean difference, the standard deviation, and the percentage error between CNCO-auto and TDCO were higher than between CNCO-cal and TDCO. A hyperdynamic cardiocirculatory state in a substantial number of patients and the hemodynamic stability making trending analysis impossible are main limitations of our study.
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J Clin Monit Comput · Aug 2016
Comparative StudyComparison of electrical velocimetry and cardiac magnetic resonance imaging for the non-invasive determination of cardiac output.
A novel algorithm of impedance cardiography referred to as electrical velocimetry (EV) has been introduced for non-invasive determination of cardiac output (CO). Previous validation studies yielded diverging results and no comparison with the non-invasive gold standard cardiac magnetic resonance imaging (CMR) has been performed. We therefore aimed to prospectively assess the accuracy and reproducibility of EV compared to CMR. 152 consecutive stable patients undergoing CMR were enrolled. ⋯ Gender, height and increasing CO and SV were associated with increased bias while not affecting reproducibility. Therefore, absolute values should not be used interchangeably in clinical routine. EV yet may find its place for clinical application with further investigation on its trending ability pending.
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J Clin Monit Comput · Aug 2016
Comparative StudyThe comparison of the technical parameters in endotracheal intubation devices: the Cmac, the Vividtrac, the McGrath Mac and the Kingvision.
Currently, there are plenty of videolaryngoscopes that appear on the market. They have different specifications. Some of these features favor the fact that they are more suited for educational purposes of future operators and others can be characterized with an excellent clinical use. ⋯ The C-MAC has a camera with the widest viewing angle (the OX axis-63.1, the axis OY-47.8), which in combination with the largest diagonal size of the display enables the operator to see the details relevant to clinical practice. It has also the strongest lamp intensity of the devices mentioned in this comparison (7800 Lx). In comparison of the clinical use in almost all compared parameters the Cmac D-blade is a winner, although for clinical education purpose we consider the Vividtrac a better device.
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J Clin Monit Comput · Aug 2016
Comparative StudyA comparison of different synchronization measures in electroencephalogram during propofol anesthesia.
Electroencephalogram (EEG) synchronization is becoming an essential tool to describe neurophysiological mechanisms of communication between brain regions under general anesthesia. Different synchronization measures have their own properties to reflect the changes of EEG activities during different anesthetic states. However, the performance characteristics and the relations of different synchronization measures in evaluating synchronization changes during propofol-induced anesthesia are not fully elucidated. ⋯ Moreover, PCMI, NI, DET correlated closely with each other and they had a better robustness to noise and higher correlation with BIS and C eff than other synchronization indexes. Propofol caused EEG synchronization changes during the anesthetic period. Different synchronization measures had individual properties in evaluating synchronization changes in different anesthetic states, which might be related to various forms of neural activities and neurophysiological mechanisms under general anesthesia.