Managing the problem of hyperleukocytosis in acute leukemia

The presence of very high numbers of circulating leukemic blast cells is reported to be associated with an increased risk of fatal complications secondary to hyperviscosity of blood and leukostasis, tumor lysis causing metabolic derangements, intravascular coagulopathy, and proliferation of leukemic cells in the brain leading to intracranial hemorrhage. Transfusions of red cells further increases the possibility of fatal leukostasis. Recommendations for care of these patients include adequate hydration, alkalinization, control of uric acid production with allopurinol, correction of the many possible fluid and electrolyte problems, possible use of hemodialysis, avoidance of excessive transfusions, and the careful use of antileukemic drugs at the outset of therapy. Cranial radiation, leukapheresis, and exchange transfusions have been used in the hope of preventing the sometimes fatal complications in leukemic patients with hyperleukocytosis. However, the effectiveness of these techniques remains in question.