Early plasmapheresis in patients with thrombotic thrombocytopenic purpura.

OBJECTIVES

To investigate the relationship of thrombotic thrombocytopenic purpura to adult respiratory distress syndrome (ARDS) and study the responses of thrombotic thrombocytopenic purpura patients to early plasmapheresis.

DESIGN

Case series.

SETTING

ICU of a university hospital.

PATIENTS

Twenty-four consecutive patients with thrombotic thrombocytopenic purpura, with various periods of time (1 to 18 days) having elapsed since the onset of this condition. Patients ranged in age from 17 to 66 yrs.

INTERVENTIONS

Plasmapheresis, using intermittent flow separators, was instituted soon after the patients' ICU admission. The retinoscopic findings on admission and the relationship of Pao2 to platelet counts before and after plasmapheresis therapy were recorded. Antiplatelet agents were given to the survivors to prevent relapses.

MEASUREMENTS AND MAIN RESULTS

Eighteen patients survived and six died. Plasmapheresis was administered for a range of 1 to 5 days (mean 3) and 3 to 18 days (mean 9.8) in survivors and nonsurvivors, respectively (p less than .001). Four patients with confluent fundus hemorrhages died and seven without these fundoscopic findings had easily controlled disease. Increases in Pao2 paralleled increases in platelet counts after plasmapheresis (p less than .001) in this small series of patients. Three of 18 discharged survivors relapsed over a period of 3 to 56 months of follow-up.

CONCLUSIONS

Early introduction of plasmapheresis in thrombotic thrombocytopenic purpura seems to increase the survival rate and to halt the development of ARDS. Fundus findings may be a prognostic factor in thrombotic thrombocytopenic purpura. The antiplatelet agents seem to be efficacious in the prevention of relapses.