Microembolism syndrome: acute respiratory failure and disseminated intravascular coagulation.

Abstract

Summary: Haematological studies were performed in thirteen patients with acute respiratory failure secondary to trauma (10 cases), or other causes in which clinical features suggesting disseminated intravascular coagulation were present including shock, haemorrhagic manifestations and central nervous system, renal, endocrine and hepatic dysfunction. In the four fatal cases features of intravascular clotting shown at autopsy included focal haemorrhages, thrombi and infarcts. Thrombocytopenia, decreased factor II levels and elevated fibrin split products were observed in all patients. Levels of other coagulation factors varied but serial changes followed a pattern characteristic of disseminated intravascular coagulation. Ten patients had low levels of plasminogen initially. Serial thrombin times were not greatly prolonged and euglobulin lysis times were lengthened. Red cell fragmentation and progressive anaemia in all cases, combined with either a decrease in haptoglobin or a rise in plasma haemoglobin in nine patients, provided evidence of microangiopathic haemolysis. β1A-globulin (C'3) was sub-normal in nine of twelve patients studied. These data demonstrate disseminated intravascular coagulation leading to secondary fibrinolysis, microangiopathic haemolysis and, apparently, complement activation. In the light of both clinical and experimental observations, disseminated intravascular coagulation is an important pathogenic mechanism in acute respiratory failure of diverse aetiologies, and explains many of its features.