Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2020
A simplified 4-parameter model of volumetric capnograms improves calculations of airway dead space and slope of Phase III.
To evaluate a compact and easily interpretable 4-parameter model describing the shape of the volumetric capnogram, and the resulting estimates of anatomical dead space (VDAW) and Phase III (alveolar plateau) slope (SIII). Data from of 8 mildly-endotoxemic pre-acute respiratory distress syndrome sheep were fitted to the proposed 4-parameter model (4p) and a previously established 7-parameter model (7p). Root mean square error (RMSE) and Akaike information criterion (AIC), as well as VDAW and SIII derived from each model were compared. ⋯ Mean differences between VDAW (2.1 ± 0.04 ml) and SIII (0.047 ± 0.004 mmHg/ml) from 7 and 4p were significant (p < 0.001), but within the observed cycle-by-cycle variability. The proposed 4-parameter model of the volumetric capnogram improves data fitting and estimation of VDAW and SIII as compared to the 7-parameter model of reference. These advantages support the use of the 4-parameter model in future research and clinical applications.
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J Clin Monit Comput · Dec 2020
Observational StudyAccuracy of the non-invasive Tcore™ temperature monitoring system to measure body core temperature in abdominal surgery.
An accurate determination of body core temperature is crucial during surgery in order to avoid and treat hypothermia, which is associated with poor outcome. In a prospective observational study, we evaluated the suitability of the Tcore™ device (Drägerwerk AG & Co. KGaA, Lübeck, Germany)-a non-invasive thermometer-to accurately determine core body temperature. ⋯ In a repeated-measurements version of the Bland and Altman test, a bias of - 0.02 °C and 95% limits of agreement of - 0.48 to 0.44 °C were calculated. In a population analysis, a median absolute error of 0 [- 0.1; + 0.1] °C, a bias of 0 [- 0.276; 0.271] % and an inaccuracy of 0.276 [0.274; 0.354] % was determined. Although the Tcore™ sensor was attached to the frontal skin, it provided an accurate measurement of core body temperature in the investigated intraoperative setting.
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J Clin Monit Comput · Dec 2020
Heart rate variability and surgical pleth index under anesthesia in poor and normal sleepers.
Poor sleep quality is associated with autonomic dysfunctions and altered pain perception and tolerance. To investigate whether autonomic dysregulations related to insomnia would still exist under general anesthesia, we adopt heart rate variability (HRV) analysis to evaluate ANS activity and surgical pleth index (SPI) to compare nociceptive/anti-nociceptive balance. We enrolled 61 adult females scheduled for gynecological surgeries under general anesthesia. ⋯ Patients with different sleep qualities did not exhibit different SPI levels in all four periods. Poor sleepers exhibited attenuated parasympathetic activities at the baseline but no differences after the induction. Nociceptive/anti-nociceptive balance seems not be altered by poor sleep condition under general anesthesia.
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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
Multicenter StudyEffects of a standardized distraction on caregivers' perceptive performance with avatar-based and conventional patient monitoring: a multicenter comparative study.
Patient monitoring requires constant attention and may be particularly vulnerable to distractions, which frequently occur during perioperative work. In this study, we compared anesthesia providers' perceptive performance and perceived workload under distraction for conventional and avatar-based monitoring, a situation awareness-based technology that displays patient status as an animated patient model. In this prospective, multicenter study with a within-subject design, 38 participants evaluated scenarios of 3- and 10-s durations using conventional and avatar-based monitoring, under standardized distraction in the form of a simple calculation task. ⋯ Participants rated perceived workload lower under distraction with the avatar in the 3-s scenario: 65 (IQR 40-79) vs. 75 (IQR 51-88), p = 0.007, MoD: 9 (95% CI 3 to 15), and in the 10-s scenario: 68 (IQR 50-80) vs. 75 (IQR 65-86), p = 0.019, MoD: 10 (95% CI 2 to 18). Avatar-based monitoring improved anesthesia providers' perceptive performance under distraction and reduced perceived workload. This technology could help to improve caregivers' situation awareness, especially in high-workload situations.