Treatment of the acute respiratory distress syndrome includes both supportive measures and correction of the underlying cause. Various pharmacological interventions have been proposed to limit the severity of lung injury and enhance the healing process, including exogenous surfactant, inhaled vasodilators (mainly nitric oxide), corticosteroids, prostaglandin E1, antioxidants (N-acetylcysteine), ketoconazole and other substances. Some of these interventions are administered via the airways, for example inhaled nitric oxide or liquid ventilation with perfluorocarbons. Some have beneficial effects on surrogate end-points such as pulmonary gas exchange. However, in large prospective trials none of these pharmacological approaches have resulted in significantly improved survival in acute respiratory distress syndrome patients.