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
Observational StudyAssessment of the peripheral microcirculation in patients with and without shock: a pilot study on different methods.
Microvascular dysfunction has been associated with adverse outcomes in critically ill patients, and the current concept of hemodynamic incoherence has gained attention. Our objective was to perform a comprehensive analysis of microcirculatory perfusion parameters and to investigate the best variables that could discriminate patients with and without circulatory shock during early intensive care unit (ICU) admission. This prospective observational study comprised a sample of 40 adult patients with and without circulatory shock (n = 20, each) admitted to the ICU within 24 h. ⋯ While lactate, BE, CRT, PPI and Tskin-diff did not differ significantly between the groups, shock patients had lower baseline tissue oxygen saturation (StO2) [81 (76-83) % vs. 86 (76-90) %, p = 0.044], lower StO2min [50 (47-57) % vs. 55 (53-65) %, p = 0.038] and lower StO2max [87 (80-92) % vs. 93 (90-95) %, p = 0.017] than patients without shock. Additionally, dynamic NIRS variables [recovery time (r = 0.56, p = 0.010), descending slope (r = - 0.44, p = 0.05) and ascending slope (r = - 0.54, p = 0.014)] and not static variable [baseline StO2 (r = - 0.24, p = 0.28)] exhibited a significant correlation with the administered dose of norepinephrine. In our study with critically ill patients assessed within the first twenty-four hours of ICU admission, among the perfusion parameters, only NIRS-derived parameters could discriminate patients with and without shock.
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J Clin Monit Comput · Dec 2020
Does it make difference to measure diaphragm function with M mode (MM) or B mode (BM)?
Diaphragm dysfunction occurs in mechanically ventilated subjects. Recent literature suggests that diaphragm thickening fraction (DTF) measured by ultrasound can be useful to predict weaning outcome. However, there is no standardized approach in the measurement of diaphragm thickness (DT) and limited data exists comparing different measurement techniques of diaphragm thickness (M mode-MM or B mode-BM). ⋯ BM and MM tidal diaphragm measurements during the inspiratory (0.3 ± 0.08 and 0.31 ± 0.08 cm; P = 0.022), expiratory (0.24 ± 0.07 and 0.24 ± 0.07 cm; P = 0.315) phases and tidal DTF were (27 ± 16 and 31 ± 14%, P = 0.089) respectively. Results of our study suggests that except tidal inspiratory diaphragm thickness, all thickness and excursion measurements with MM and BM are very compatible with each other. Further studies are necessarry to confirm our results and to standardize the measurements of diaphragm.