PATIENTS with an acute, diffuse pulmonary infiltrate pose substantial diagnostic and treatment challenges. Some such patients' conditions may qualify, when first examined, for a diagnosis of adult respiratory distress syndrome (ARDS). That syndrome consists of the presence of diffuse pulmonary infiltrates of unknown cause, arterial hypoxemia (due to a "right-to-left shunt" mechanism), and a normal pulmonary capillary ("wedge") pressure.1 Other patients with somewhat less severe involvement may seem to be approaching fulfillment of the criteria for a diagnosis of ARDS.
Part of the challenge posed by such patients is that some 30% have pulmonary infection as the basis for ARDS2; in the remainder, the pathogenetic basis is noninfectious and related to a biochemical-cellular sequence that has yet to be defined. Treatment of the latter is presently supportive; good support includes the avoidance of procedures that may further compromise respiratory function. It is also clear, however, that when infection
Moser KM. Diagnosis of Acute, Diffuse Pulmonary Infiltrates. JAMA. 1984;252(15):2044-2047. doi:10.1001/jama.1984.03350150044019