Hyperviscosity Syndrome

Hyperviscosity Syndrome is a topic covered in the 5-Minute Emergency Consult.

To view the entire topic, please or .

Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:

-- The first section of this topic is shown below --

Basics

Description

  • Hyperviscosity syndrome (HVS) is the clinical consequence of increased blood viscosity
  • The classic clinical symptoms are the triad of mucosal bleeding, visual disturbances, and neurologic signs
  • Viscosity is the resistance a material has to change in form
  • The higher the blood viscosity, the more the internal resistance to blood flows
  • Increased cardiac output is required to provide adequate perfusion of hyperviscous blood
  • Oxygen delivery is impaired as transit through the microcirculatory system slows. This impaired microcirculatory oxygenation gives rise to the clinical symptoms of this syndrome

Etiology

  • Hyperviscosity occurs when there is elevation of either the cellular or acellular components of circulating blood
  • Acellular (protein) hyperviscosity:
    • The most common cause (85–90%) of hyperviscosity is increased concentration of γ globulins:
      • Monoclonal gammopathies: From malignant diseases like Waldenstrom macroglobulinemia and multiple myeloma
      • Polyclonal gammopathies: Usually rheumatic diseases (very rare)
  • Cellular (blood cell) hyperviscosity:
    • Much less common (10–15%)
    • Increased numbers of RBC, as in polycythemia vera
    • Increased concentration (>100,000) of WBC, as in acute and chronic leukemia
    • Thrombocytosis

-- To view the remaining sections of this topic, please or --

Basics

Description

  • Hyperviscosity syndrome (HVS) is the clinical consequence of increased blood viscosity
  • The classic clinical symptoms are the triad of mucosal bleeding, visual disturbances, and neurologic signs
  • Viscosity is the resistance a material has to change in form
  • The higher the blood viscosity, the more the internal resistance to blood flows
  • Increased cardiac output is required to provide adequate perfusion of hyperviscous blood
  • Oxygen delivery is impaired as transit through the microcirculatory system slows. This impaired microcirculatory oxygenation gives rise to the clinical symptoms of this syndrome

Etiology

  • Hyperviscosity occurs when there is elevation of either the cellular or acellular components of circulating blood
  • Acellular (protein) hyperviscosity:
    • The most common cause (85–90%) of hyperviscosity is increased concentration of γ globulins:
      • Monoclonal gammopathies: From malignant diseases like Waldenstrom macroglobulinemia and multiple myeloma
      • Polyclonal gammopathies: Usually rheumatic diseases (very rare)
  • Cellular (blood cell) hyperviscosity:
    • Much less common (10–15%)
    • Increased numbers of RBC, as in polycythemia vera
    • Increased concentration (>100,000) of WBC, as in acute and chronic leukemia
    • Thrombocytosis

There's more to see -- the rest of this topic is available only to subscribers.