Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2017
Transesophageal Doppler reliably tracks changes in cardiac output in comparison with intermittent pulmonary artery thermodilution in cardiac surgery patients.
In this study a comparison of cardiac output (CO) measurements obtained with CardioQ transesophageal Doppler (TED) and pulmonary artery catheter (PAC) thermodilution (TD) technique was done in a systematic set-up, with induced changes in preload, afterload and heart rate. Twenty-five patients completed the study. Each patient were placed in the following successive positions: (1) supine, (2) head-down tilt, (3) head-up tilt, (4) supine, (5) supine with phenylephrine administration, (6) pace heart rate 80 beats per minute (bpm), (7) pace heart rate 110 bpm. ⋯ In comparison with PAC TD, the CardioQ TED showed a low mean bias, wide limits of agreement and a larger percentage error than should be expected from the precision of the two methods. However, an acceptable trending ability was found. Thus, the CardioQ TED should not replace CO measurements done by PAC TD, but could be a valuable tool in guiding therapy.
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J Clin Monit Comput · Feb 2017
Towards an optimal paradigm for intraoperative auditory nerve monitoring with auditory steady state responses.
Auditory steady state responses (ASSR) may offer an alternative to brainstem auditory evoked potentials for monitoring of the auditory nerve during surgical procedures. In the current study, we evaluated the influence of noise on ASSR characteristics in total intravenous anesthesia (TIVA). Simulated ASSR in real noise recorded during surgery under TIVA were constructed with known parameters. ⋯ Choice of parameters strongly influences detection and characteristics of ASSR. Optimal parameters enabled detection after 16 s in 45 %. Due to specific noise characteristics, modulation has a critical impact, which is currently not sufficiently recognized in ASSR studies.
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J Clin Monit Comput · Feb 2017
Heart period and blood pressure characteristics in splanchnic arterial occlusion shock-induced collapse.
The nature of hemodynamic instability typical of circulatory shock is not well understood, but an improved interpretation of its dynamic features could help in the management of critically ill patients. The objective of this work was to introduce new metrics for the analysis of arterial blood pressure (ABP) in order to characterize the risk of catastrophic outcome in splanchnic arterial occlusion (SAO) shock. Continuous ABP (fs = 1 kHz) was measured in rats during experimental SAO shock, which induced a fatal pressure drop (FPD) in ABP. ⋯ Baroreflex sensitivity (BRS) was assessed by means of a bivariate model. The approach to FPD of the animals who collapsed (FFPD) was characterized by higher BRS in the low frequency band versus SFPD animals (0.36 ± 0.15 vs. 0.19 ± 0.12 ms/mmHg, p value = 0.0196), bradycardia as indicated by the HPC (0.76 ± 0.57 vs. 1.94 ± 1.27, p value = 0.0179) and higher but unstable blood pressure as indicated by BPC (3.02 ± 2.87 vs. 1.47 ± 1.29, p value = 0.0773). The HPC and BPC indices demonstrated promise as potential clinical markers of hemodynamic instability and impending cardiovascular collapse, and this animal study suggests their test in data from intensive care patients.
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J Clin Monit Comput · Dec 2016
ReviewCerebral near-infrared spectroscopy in the care of patients during cardiological procedures: a summary of the clinical evidence.
Patients undergoing cardiological procedures generally have significant cardiovascular morbidity, and therefore these patients might be at risk for major periprocedural complications. The ability to closely monitor the hemodynamic status would present a major advantage to optimize patient care in this setting. The aim of this review is to assess the available evidence for the use of near-infrared spectroscopy (NIRS) in the care of patients during cardiological procedures. ⋯ Six studies evaluated NIRS during supraventricular and ventricular arrhythmias, one during transcatheter aortic valve implantations, and four studies assessed the use of NIRS in pediatric catheterization procedures. Overall, the studies demonstrated that NIRS provides a very quick representation of cerebral oxygen saturation and that it might identify changes that could not be predicted from standard hemodynamic monitoring. However, the evidence is currently too low to conclude that NIRS can optimize patient care during cardiological procedures.