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Hyperviscosity Syndrome

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Hyperviscosity Syndrome, Leukostasis, Hyperleukocytosis of Malignancy

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