Pulmonary edema is caused by transudation of fluid from pulmonary capillaries into the alveolar spaces and the bronchiolus. It is most frequently secondary to either increased pulmonary capillary hydrostatic pressure (cardiogenic pulmonary edema) or increased pulmonary capillary permeability (noncardiogenic pulmonary edema). Numerous systemic and pulmonary insults are capable of damaging the capillary endothelium and/or alveolar epithelium, resulting in noncardiogenic pulmonary edema. Although clinically similar, the presence of noncardiogenic pulmonary edema requires a different therapeutic approach from that of cardiogenic pulmonary edema.