American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Oct 2019
ReviewRe-appraisal of Ventilator-free Days in Critical Care Research.
Ventilator-free days (VFDs) are a commonly reported composite outcome measure in acute respiratory distress syndrome trials. VFDs combine survival and duration of ventilation in a manner that summarizes the "net effect" of an intervention on these two outcomes. However, this combining of outcome measures makes VFDs difficult to understand and analyze, which contributes to imprecise interpretations. ⋯ Using simulations, we illustrate how the statistical test with optimal power depends on the relative contributions of mortality and ventilator duration on the composite effect size. Finally, we recommend a simple analysis and reporting framework using the competing risk approach, which provides clear information on the effect size of an intervention, a statistical test and measure of confidence with the ability to adjust for baseline factors and allow interim monitoring for trials. We emphasize that any approach to analyzing a composite outcome, including other "failure-free day" constructs, should also be accompanied by an examination of the components.
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Am. J. Respir. Crit. Care Med. · Oct 2019
A Novel Assay for Neutrophil Extracellular Traps (NETs) Formation Independently Predicts Disseminated Intravascular Coagulation and Mortality in Critically Ill Patients.
Rationale: Neutrophil extracellular traps (NETs) are important in the host defense against infection, but they also promote intravascular coagulation and multiorgan failure in animal models. Their clinical significance remains unclear, and available assays for patient care lack specificity and reliability. Objectives: To establish a novel assay and test its clinical significance. ⋯ Mitogen-activated protein kinase activation by IL-8 has been identified as a major pathway of NET formation in patients. Conclusions: This assay directly measures the NET-forming capacity in patient plasma. This could guide clinical management and enable identification of NET-inducing factors in individual patients for targeted treatment and personalized ICU medicine.