Hematologic emergencies. Management of hyperleukocytic syndrome, DIC, and thrombotic thrombocytopenic purpura.

Three hematologic emergencies are reviewed in this article: the hyperleukocytic syndrome, disseminated intravascular coagulopathy (DIC), and thrombotic thrombocytopenic purpura (TTP). The hyperleukocytic syndrome most commonly occurs in patients with acute myelogenous leukemia. It commonly affects the lungs and may cause intracranial hemorrhage. Long-term control is accomplished only by inducing a remission of the leukemia. Patients with DIC may have excessive clotting, uncontrolled bleeding, or both. Infections are the most common cause; cases in obstetric patients are usually due to abruptio placentae or retained dead fetus. Any acute leukemia can cause DIC. The underlying disorder is the usual cause of death. TTP is thought to be due to a substance or substances in the plasma that initiate marked platelet aggregation in the microcirculation. It affects persons of any age and either sex. Plasmapheresis is the preferred treatment.