Adult respiratory distress syndrome (ARDS): the basics

The term adult respiratory distress syndrome (ARDS) was first introduced by Ashbaugh and Petty more than two decades ago. Since then, our understanding of this clinicopathologic entity has increased significantly. However, little therapeutic progress has been achieved, and the mortality remains high. ARDS is characterized by diffuse pulmonary microvascular injury resulting in increased permeability and, thus, noncardiogenic pulmonary edema. Ventilation-perfusion lung studies have demonstrated that the predominant pathogenesis of hypoxemia in ARDS is related to intrapulmonary shunts. Common symptoms include dyspnea, tachypnea, dry cough, retrosternal discomfort, and moderate to severe respiratory distress. In most cases the diagnosis of ARDS is that of exclusion. The mainstay of therapy for this syndrome is the management of the underlying disorder causing it. To date, there are no specific pharmacologic interventions of proven value for the treatment of ARDS. Once the potentially treatable sources have been found and their therapy started, the main treatment for ARDS is supportive.