Hemostatic imbalances produced by plasma exchange.

Ten patients who underwent intensive therapeutic plasma exchange were studied prospectively to determine the nature and extent of changes induced in their coagulation mechanisms. The patients' plasma was replaced with serum albumin and normal saline. Significant changes were noted acutely in the prothrombin time, activated partial thromboplastin time, plasma fibrinogen, and platelet counts. Chronically, significant decreases were found in plasma fibrinogen concentrations and platelet counts. Intensive plasma exchange with fluids devoid of coagulation factors results in defects in the normal hemostatic mechanism.