256. Snowmageddon - An approach to Leukostasis

Leukostasis is a medical emergency characterized by symptomatic hyperleukocytosis where large, rigid white blood cell blasts cause mechanical obstruction in the microvasculature. While hyperleukocytosis is a laboratory finding of white blood cell counts exceeding 100 x 10⁹/L, leukostasis is a clinical diagnosis defined by end-organ damage, most commonly affecting the brain and lungs. Patients typically present with neurological deficits, respiratory distress, or signs of tumor lysis syndrome (TLS) and disseminated intravascular coagulation (DIC). Management prioritizes rapid cytoreduction through chemotherapy, such as hydroxyurea or induction regimens, to reduce the blast burden. Although leukophoresis can physically remove circulating cells, a 2020 meta-analysis of 1,743 AML patients demonstrated that the procedure does not improve early mortality and should not delay definitive chemotherapy. Essential supportive care includes aggressive hydration for TLS and avoiding red blood cell transfusions, which can further increase blood viscosity and exacerbate tissue hypoxia.