Acute respiratory distress syndrome epidemiology and pathophysiology

Acute respiratory distress syndrome is a devastating syndrome of lung injury following known risk factors, with a persistently high mortality. A consensus conference definition of ARDS has been adopted by clinical researchers, but potential problems remain. ARDS may represent more than one entity, and radiographic and mechanical differences between pulmonary versus extrapulmonary initiated ARDS have been described. There is increasing recognition of inflammatory mediators in the pathophysiology of acute lung injury. Surfactant abnormalities contribute to the associated lung dysfunction. A growing body of evidence supports the presence of VILI and a potential mechanism for developing MOSF, and has led to new management strategies. The importances of apoptosis to the repair process, and mechanisms that may lead to persistent fibrosis, such as the activation of the coagulant pathway with fibrin deposition, are increasingly recognized.