[Acute respiratory distress syndrome].

The pathophysiology of acute respiratory distress syndrome (ARDS) is characterized by pulmonary edema due to extravasation from capillary lesions in the endothelium. A clinical diagnosis is made when there is a predisposing cause (sepsis and pneumonia being the most common) that gives rise to acute respiratory insufficiency (PaO2/FiO2 ratio (3/4) 200 mmHg, bilateral infiltrates visible on a chest film and hemodynamic or other clinical signs of left cardiac insufficiency). Most patients require invasive support ventilation at a high FiO2 and positive end-expiratory pressure (PEEP). The only therapeutic approach available at this time associated with a highly significant decrease in mortality in patients with ARDS is ventilation at low flow volumes (6 ml/kg) and moderate levels of PEEP (approximately 10 cmH2O).