Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2020
Optimized electrical bioimpedance measurements of abdominal wall on a porcine model for the continuous non-invasive assessment of intra-abdominal pressure.
This work describes the optimization of electrical bioimpedance measurements for indirect intra-abdominal pressure (IAP) assessment. The experimental run was performed on a female Sus scrofa domesticus (domestic pig). Different values of IAP were induced by inflation of the abdominal cavity, using a trocar placed near the umbilicus over the linea alba. ⋯ An exponential trend linking between the bioimpedance values at 99.8 kHz and the IAP was found. Non-optimized electrode placement presented a strongly reduced sensitivity to IAP changes above 7 mmHg. Upon optimization and placing the electrodes with a separation of about 3.6 times the measured abdominal wall thickness, the sensitivity for high IAP drastically increased, allowing continuous non-invasive monitoring of IAP, confirming the optimization method proposed in this work.
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J Clin Monit Comput · Dec 2020
Reliability of B-line quantification by different-level observers and a software algorithm using point-of-care lung ultrasound.
Quantification of B-lines on lung ultrasonographs is operator-dependent and considered a semi-quantitative method. To avoid this variability, we designed a software algorithm for counting B-lines. We compared the number of B-lines obtained in real-time by observers with three different levels of experience and by the software algorithm, and analyzed intra-rater variability in terms of the estimated number of B-lines in two successive examinations. ⋯ For all lung zones, the intraclass correlation for B-lines counting between OB1 and OB2 was 0.663; between OB1 and OB3, 0.559; and between OB1 and OBS, 0.710. OBS had a better concordance coefficient (0.752) between the first and the second measurements than did the human observers. Our results show that the software algorithm for B-lines counting is a potentially promising alternative when observers have little lung ultrasound experience.
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J Clin Monit Comput · Dec 2020
Comment LetterThe artificial count of artifacts for thoracic ultrasound: what is the clinical usefulness?
Many works in the literature have shown that the increase in the number of B lines is a nonspecific sign of underlying pulmonary disease. Actually these artifacts are the result of a physical effect of ultrasound between the chest wall and the pulmonary air. Nevertheless the intra- and inter-operator variability in B-lines counting does not only reside only in the count itself but depends also on the type and frequency of the probe used, as well as the ultrasound scan machine setting and the patient's chest shape. In our opinion, proposing a software algorithm to count lines B seems like an unproductive effort.
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J Clin Monit Comput · Dec 2020
The Peripheral Perfusion Index tracks systemic haemodynamics during general anaesthesia.
Stable intraoperative haemodynamics are associated with improved outcome and even short periods of instability are associated with an increased risk of complications. During anaesthesia intermittent non-invasive blood pressure and heart rate remains the cornerstone of haemodynamic monitoring. Continuous monitoring of systemic blood pressure or even -flow requires invasive or advanced modalities creating a barrier for obtaining important real-time haemodynamic insight. ⋯ After stabilizing a second HUT decreased PPI 59% (49-76), SV 33% (28-37), CO 31% (28-36), and MAP 34% (26-38). Restoration of preload with PE increased PPI by 607% (218-1078), SV by 96% (82-116), CO by 65% (56-99), and MAP by 114% (83-147). During general anaesthesia changes in PPI tracked changes in systemic haemodynamics.