Seminars in respiratory and critical care medicine
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The acute respiratory distress syndrome (ARDS) phenotype was first described over 50 years ago and since that time significant progress has been made in understanding the biologic processes underlying the syndrome. Despite this improved understanding, no pharmacologic therapies aimed at the underlying biology have been proven effective in ARDS. Increasingly, ARDS has been recognized as a heterogeneous syndrome characterized by subphenotypes with distinct clinical, radiographic, and biologic differences, distinct outcomes, and potentially distinct responses to therapy. ⋯ Finally and most promisingly, biologic subphenotypes or endotypes have increasingly been identified using plasma biomarkers, genetics, and unbiased approaches such as latent class analysis. The potential of precision medicine lies in identifying novel therapeutics aimed at ARDS biology and the subpopulation within ARDS most likely to respond. In this review, we discuss the challenges and approaches to subphenotype ARDS into clinical, radiologic, severity, and biologic phenotypes with an eye toward the future of precision medicine in critical care.
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Semin Respir Crit Care Med · Feb 2019
ReviewFluid Management in Acute Respiratory Distress Syndrome.
One of the defining features of acute respiratory distress syndrome (ARDS) is noncardiogenic pulmonary edema, resulting from increased permeability of the alveolar-capillary barrier and passage of protein-rich fluid into the interstitium and alveolar spaces. The loss of protein from the intravascular space disrupts the normal oncotic pressure differential and causes patients with ARDS to be particularly sensitive to the hydrostatic forces that correlate with intravascular volume. ⋯ These physiologic observations have led to a series of studies examining the impact of fluid management on the development of, resolution of, survival from, and long-term outcomes from ARDS. While questions remain, the current literature makes it clear that fluid management is an integral part of the care of patients with ARDS.
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Semin Respir Crit Care Med · Feb 2019
ReviewPathophysiology and Management of Acute Respiratory Distress Syndrome in Obese Patients.
A rising prevalence of obesity is reported over time and throughout the world. At the same time, the acute respiratory distress syndrome (ARDS) remains an important public health problem, accounting for approximately 10% of intensive care unit admissions and leading to significant hospital mortality. Even in the absence of acute illnesses, obesity affects respiratory mechanics and gas exchange in the setting of a restrictive disease. ⋯ Then the diagnostic challenges due to obesity-related artifacts of the different imaging techniques will be presented. A subsequent, detailed description of the altered respiratory anatomy and physiology of obesity will provide help in selecting an optimal, individually tailored strategy of support. Furthermore, we will discuss how esophageal manometry should be used to adjust the settings of positive end-expiratory pressure and tidal volume; the challenges of prone positioning and extracorporeal support; and the optimal strategies for weaning from mechanical ventilation, including when and how to perform a tracheostomy.
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Semin Respir Crit Care Med · Feb 2019
ReviewDefinitions, Epidemiology, Clinical Risk Factors, and Health Disparities in Acute Respiratory Distress Syndrome.
Acute respiratory distress syndrome (ARDS) is a syndrome of inflammatory lung injury currently defined as the rapid onset of hypoxemia and radiographic opacities from a recent direct or indirect insult that is not explained by other causes. While the diagnostic criteria used to define ARDS are helpful in the clinical setting, they are not entirely specific for the characteristic pathophysiology of diffuse alveolar lung damage. ⋯ Within these limitations, ARDS appears to be a condition that is relatively rare within the general population but common within the context of the intensive care unit. Furthermore, the frequency and outcomes of ARDS seem to vary between populations, with no clearly discernible temporal trends in incidence or case fatality that are uniform across studies.