Elevated fibrin(ogen) degradation products in the adult respiratory distress syndrome.

During a 60-h period after the onset of either the adult respiratory distress syndrome (ARDS) in 14 patients, or similar predisposing conditions without respiratory insufficiency (non-ARDS) in 12 patients, blood was obtained 3 times for assessment of coagulation, fibrinolysis, and complement. Platelet counts decreased progressively in both groups, and a platelet release protein, Beta-thromboglobulin, was similarly increased in both groups. Fibrinopeptide A concentrations were similarly increased in both groups. Hemolytic activity of complement components C3 and C5 was within the normal range in both groups. In contrast, the fibrin/fibrinogen degradation product, D-antigen, was significantly increased in the ARDS group over all time periods (p < 0.01). These findings suggested that higher concentrations of circulating fibrin/fibrinogen degradation products are associated with ARDS itself, either as a marker or more extensive microvascular injury or as a possible mediator of injury.