Outcome of severe adult thrombotic microangiopathies in the intensive care unit

Objective: Thrombotic microangiopathies, namely thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, are uncommon microvascular occlusive diseases. Despite the dramatic improvement in the outcome by exogenous plasma supply, either through plasma infusion or through plasma exchange, patients frequently require support in the intensive care unit. In the present study, we evaluated the outcome of a large cohort of patients with severe thrombotic microangiopathies. Design: A retrospective multicenter study from January 1998 to June 2001. Setting: Fourteen French university hospital medical intensive care units. Patients: Sixty three adult patients with severe thrombotic microangiopathies. Measurements and results: Of the 63 patients, 19 had a clinical presentation of thrombotic thrombocytopenic purpura, 18 had hemolytic uremic syndrome and 26 had combined neurologic and renal failures. Infections were the main etiology associated with thrombotic microangiopathies. The mortality rate was 35%. Of the survivors, all achieved complete remission. Whereas neurologic failure assessed through the Glasgow coma scale was an independent predictor of mortality [HR = 0.845 (CI 95%: 0.759 - 0.940), P = 0.002], renal impairment did not appear to be an adverse prognostic factor. The use of plasma exchange was independently associated with survival [HR = 0.269 ( CI 95%: 0.104 - 0.691), P = 0.006]. Conclusions: Thrombotic microangiopathies with severe organ dysfunctions leading to hospitalization in the intensive care unit are associated with high mortality. Neurologic impairment appears to be the main adverse prognostic factor correlated to mortality, and the study confirms the importance of plasma exchange in the treatment of high-risk patients.