Adult respiratory distress syndrome is a common respiratory emergency which follows a variety of severe direct and indirect lung insults. Major features are severe respiratory distress, diffuse pulmonary infiltrations, reduced compliance and refractory hypoxemia due to shunt effect. Surfactant abnormalities may play a role in the mechanical derangement of lung function. Supportive care with mechanical ventilation and positive end expiratory pressure results in survival of approximately 50 percent of patients. Only minimal abnormalities in lung function are found in long-term survivors.