II. Causes
- Oncology related cases
- Acute Myelogenous Leukemia (AML), accounts for 20% of cases
- Chronic Myelogenous Leukemia (CML) if in Blast Crisis, evolution to AML
- Multiple Myeloma
- Waldenstrom's Macroglobulinemia (10-30% of cases)
- Other causes
III. Pathophysiology
- Overall increased serum viscosity
- Dramatically increased cell counts
- Red Blood Cells: Polycythemia Rubra Vera
- White Blood Cells: Leukostasis (with White Blood Cells >100,000)
- Especially seen in acute leukemic Blast Crisis (AML or CML)
- Increased circulating serum Immunoglobulins
- Immunoglobulins coat Red Blood Cells
- Results in increased viscosity and sludging of blood cells
- End result is end organ decreased perfusion
IV. Signs
- Spontaneous bleeding from mucous membranes
- Fever in 80% of patients
- Pulmonary symptoms in 30% of cases
- Dyspnea
- Hypoxia
- Pulmonary Infiltrates (CXR) may be seen
-
Vision change
- Hemorrhagic Retinal veins (appear as sausages, pathognomonic)
- Neurologic symptoms (e.g. Transient Ischemic Attack) in 40% of cases
V. Labs
-
Complete Blood Count
- Marked increased in a cell line
- White Blood Cells markedly increased or Hyperleukocytosis (e.g. Acute Myelogenous Leukemia)
- Hyperleukocytosis with White Blood Cell Count >100,000 (>50,000 in some criteria)
- Red Blood Cells markedly increased (e.g. Polycythemia Rubra Vera)
- White Blood Cells markedly increased or Hyperleukocytosis (e.g. Acute Myelogenous Leukemia)
- Other cell lines may be elevated
- Platelet Count falsely elevated
- Marked increased in a cell line
- Serum Electrolytes with Renal Function panel
- Hyperkalemia may be present
- Urinalysis
- Coagulation Panel (e.g. INR/PT, PTT)
- Serum viscosity: >4-5 centipoise (cP)
- Serum viscosity is normally near 1.4 cP
- Water viscosity is 1 cP
VI. Management
-
Oncologic Emergency
- Immediate Consultation with hematology and oncology
- Temporize
- Aggressive Intravenous Fluids
- Respiratory support (including Endotracheal Intubation if needed)
- Avoid transfusion
- Empiric Antibiotics
- Fever is present in 80% of patients who also have severe Leukocytosis on Chemotherapy
- Antibiotics are indicated to cover the differential diagnosis in this high risk group
- Exercise caution with diuresis (e.g. CHF)
- May exacerbate Leukostasis
- Decrease cellular load (cytoreduction)
- Multiple Myeloma
- Plasmapheresis
- Polycythemia
- Phlebotomy
- Leukostasis
- Induction Chemotherapy (first-line, only measure associated with reduced mortality)
- Leukapheresis
- Hydroxyurea
- May be indicated in asymptomatic patients
- Dosing 50-100 mg/kg/day
- Multiple Myeloma
VII. Complications
-
Intracranial Hemorrhage
- Risk increases for first week after treatment
- Myocardial Ischemia
- Acute Limb Ischemia
- Acute Kidney Injury
- Disseminated Intravascular Coagulation or DIC (40% of cases)
-
Tumor Lysis Syndrome
- Prophylaxis with Intravenous Fluids and Allopurinol prior to Chemotherapy
VIII. Prognosis
- Untreated mortality approaches 40% in first week
IX. References
- Aurora and Herbert in Herbert (2013) EM:Rap 13(10): 1-4
- Long, Long and Koyfman (2020) Crit Dec Emerg Med 34(11): 17-24
- Higdon (2006) Am Fam Physician 74:1873-80 [PubMed]
- Higdon (2018) Am Fam Physician 97(11):741-8 [PubMed]
- Zuckerman (2012) Blood 120(10): 1993-2002 [PubMed]