Hyperviscosity Syndrome Workup

Updated: Sep 09, 2021
  • Author: Thomas J Hemingway, MD, FACEP; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Laboratory Studies

The diagnosis of hyperviscosity syndrome (HVS) is confirmed by measurement of elevated serum viscosity in a patient with characteristic clinical manifestations of HVS. No exact diagnostic cut-off exists for serum viscosity, as different patients will have symptoms at different values. A clue to the need for measurement of serum viscosity may be that the laboratory has difficulty performing chemical tests, because hyperviscous blood can clog analyzers.

The normal reference range for serum viscosity is 1.4-1.8 Centipoises (1.0 being the viscosity of water). Symptoms usually are not seen before the viscosity reaches 4 Centipoises, and patients with HVS usually present with a serum viscosity greater than 5 Centipoises. Typically, the higher the viscosity, the worse the symptoms.

Other laboratory testing is as follows:

  • Obtain a peripheral blood smear with the complete blood count (CBC); rouleaux formation is often present with increased serum viscosity

  • The white blood cell count (WBC) is typically 100,000/μL or greater in leukostasis causing HVS, but it may be lower in the blast crises of the leukemias

  • Consider measuring total protein (TP) and albumin, as in the paraproteinemias; a globulin gap (TP – albumin = 4 or greater) may exist

  • Consider adding a metabolic panel and electrolytes, as derangements such as hypercalcemia, hyperphosphatemia, and hyperkalemia are common and may require specific treatment (be sure not to contribute to pseudohyperkalemia secondary to the increased cellular lysis through poor venipuncture technique; use a larger needle, withdraw slowly and, if in doubt, order a plasma rather than serum potassium level, which will be more reliable)

  • Consider coagulopathy workup (eg, blood count, type and screen, prothrombin time, activated partial thromboplastin time, platelet count) if the patient presents with hemorrhage

  • Tailor additional workup (eg, chest radiography, brain computed tomography or magnetic resonance imaging) to the patient's presentation

  • Consider panculture and urinalysis; multiple myeloma is complicated frequently by infections; in nonneutropenic patients, infections are usually secondary to Streptococcus pneumoniae or Haemophilus influenzae

  • If the patient has not been diagnosed with an underlying pathologic process that could have caused the HVS (eg, multiple myeloma, Waldenström macroglobulinemia, hyperproliferative blood cell dysplasias), consider adding serum and urine electrophoresis to search for such disorders.


Imaging Studies

A computed tomography (CT) scan of the head is indicated for patients who present with altered level of consciousness, seizures, or focal neurologic deficits. Contrast dye is contraindicated in patients with multiple myeloma because of the increased risk of renal failure.

A chest radiograph may be indicated to rule out infection. It also may reveal congestive heart failure (CHF). High-output failure can be caused by hyperviscosity or anemia.