Acute respiratory distress syndrome.

Acute Respiratory Distress Syndrome (ARDS) is defined by bilateral diffuse infiltrates on chest radiography, a PO2/FiO2 ratio < 200, and noncardiogenic pulmonary edema. Pathophysiologically it is characterized by disruption of the alveolar lining and capillary endothelium, alveolar edema, protein exudation coupled with a marked inflammatory response and subsequent fibrosis and a resultant ventilation-perfusion mismatch. Effective treatment strategies include low tidal volume ventilation with positive end expiratory pressure, careful fluid management and good supportive care.