American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Oct 2020
WITHDRAWN: Proposal for Initiative of Evidence-based Treatment of COVID-19 Patients with Worsening Hypoxia.
Ahead of Print article withdrawn by publisher.
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Am. J. Respir. Crit. Care Med. · Oct 2020
Machine Learning Classifier Models Can Identify ARDS Phenotypes Using Readily Available Clinical Data.
Rationale: Two distinct phenotypes of acute respiratory distress syndrome (ARDS) with differential clinical outcomes and responses to randomly assigned treatment have consistently been identified in randomized controlled trial cohorts using latent class analysis. Plasma biomarkers, key components in phenotype identification, currently lack point-of-care assays and represent a barrier to the clinical implementation of phenotypes. Objectives: The objective of this study was to develop models to classify ARDS phenotypes using readily available clinical data only. ⋯ Model accuracy was similar when ALVEOLI (AUC, 0.94; 95% CI, 0.92-0.96) and FACTT (AUC, 0.94; 95% CI, 0.92-0.95) were used as the validation cohorts. Significant treatment interactions were observed with the clinical classifier model-assigned phenotypes in both ALVEOLI (P = 0.0113) and FACTT (P = 0.0072) cohorts. Conclusions: ARDS phenotypes can be accurately identified using machine learning models based on readily available clinical data and may enable rapid phenotype identification at the bedside.
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Am. J. Respir. Crit. Care Med. · Oct 2020
Tissue Doppler Imaging of the Diaphragm in Healthy Subjects and Critically Ill Patients.
Rationale: Tissue Doppler imaging (TDI) is an echocardiographic method that measures the velocity of moving tissue. Objectives: We applied this technique to the diaphragm to assess the velocity of diaphragmatic muscle motion during contraction and relaxation. Methods: In 20 healthy volunteers, diaphragmatic TDI was performed to assess the pattern of diaphragmatic motion velocity, measure its normal values, and determine the intra- and interobserver variability of measurements. ⋯ Peak contraction velocity was strongly correlated with peak transdiaphragmatic pressure and pressure-time product, whereas Pdi-maximal relaxation rate was significantly correlated with TDI-maximal relaxation rate. Conclusions: Diaphragmatic tissue Doppler allows real-time assessment of the diaphragmatic tissue motion velocity. Diaphragmatic TDI-derived parameters differentiate patients who fail a weaning trial from those who succeed and correlate well with Pdi-derived parameters.