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Emergency And Acute Medicine: Hyperviscosity Syndrome
Basics
Description Hyperviscosity syndrome is the clinical consequence of increased blood viscosity leading to impaired microcirculatory flow and reduced tissue oxygen delivery. As viscosity rises, greater cardiac output is required to maintain perfusion, yet oxygen delivery worsens because blood transit through the microcirculation slows. The classic clinical presentation is a triad of mucosal bleeding, visual disturbances, and neurologic symptoms.
Etiology Hyperviscosity results from elevation of cellular or acellular blood components. Acellular (protein) hyperviscosity is the most common cause (85–90%) and is usually due to increased gamma globulins from monoclonal gammopathies such as Waldenström macroglobulinemia and multiple myeloma; polyclonal gammopathies from rheumatologic disease are rare. Cellular hyperviscosity (10–15%) occurs with markedly increased blood cells, including erythrocytosis in polycythemia vera, extreme leukocytosis (>100,000) in acute or chronic leukemia, and severe thrombocytosis.
Diagnosis
Signs and symptoms The classic triad includes bleeding, visual changes, and neurologic dysfunction. Hematologic manifestations are most common and include epistaxis, gingival, rectal, or uterine bleeding, prolonged postprocedural bleeding, and pruritus. Ocular findings include blurred vision, diplopia, visual loss, and characteristic funduscopic changes such as the “link-sausage” appearance of retinal veins, retinal hemorrhages, exudates, microaneurysms, and papilledema. Neurologic symptoms include headache, dizziness, vertigo, ataxia, tinnitus, hearing loss, paresthesias, peripheral neuropathy, seizures, altered mental status, coma, and intracranial hemorrhage. Renal manifestations include hematuria, sterile pyuria, and nephritic or nephrotic syndromes. Cardiovascular findings may include angina, myocardial infarction, dysrhythmias, and heart failure. Dermatologic features include Raynaud phenomenon, livedo reticularis, palpable purpura, digital infarcts, and peripheral gangrene.
History Suspect hyperviscosity syndrome in patients with the classic triad, known immunoglobulin-producing disorders, or hypercellular hematologic diseases presenting with microvascular ischemia or cardiac decompensation.
Physical exam No pathognomonic findings exist; exam reflects end-organ involvement such as mucosal bleeding, petechiae, focal neurologic deficits, heart failure signs, or abnormal funduscopic findings.
Essential workup Assess for bleeding and end-organ ischemia. Measure serum or whole blood viscosity when available. Suspect the diagnosis when laboratory processing is difficult due to serum stasis or analyzer obstruction from viscous samples.
Diagnosis tests and interpretation
Laboratory Obtain CBC with differential to assess anemia, erythrocytosis, leukocytosis, or thrombocytosis; normocytic normochromic anemia is common. Peripheral smear may show rouleaux formation, a key diagnostic clue. Check electrolytes, BUN, creatinine, and glucose; renal dysfunction is common, and pseudohyponatremia or hypercalcemia may occur in multiple myeloma. Urinalysis may show proteinuria or hematuria. Obtain coagulation studies. Perform serum and urine protein electrophoresis. Serum viscosity measurement (when available) is diagnostic; normal relative viscosity is 1.4–1.8, and symptoms usually develop at ≥4 centipoise.
Imaging Head CT is indicated in patients with neurologic symptoms to exclude intracranial hemorrhage.
Differential diagnosis Platelet disorders, inherited or acquired coagulation factor deficiencies, liver disease, vitamin K deficiency, and disseminated intravascular coagulation.
Treatment
Prehospital Initiate IV fluid resuscitation in patients with bleeding or suspected hypovolemia.
Initial stabilization/therapy Rehydrate with isotonic saline. Bleeding or ischemia often does not respond to routine therapy and requires viscosity reduction. In patients with anemia and leukemia, avoid transfusion before plasmapheresis as it may worsen viscosity.
Emergency department management Provide supportive care and obtain early hematology consultation. Phlebotomy is a temporizing measure in severe cases with coma or seizures when plasmapheresis is not immediately available; remove 100–200 mL of whole blood and replace with isotonic saline, ideally after consultation, and is first-line in polycythemia vera. Plasmapheresis or leukapheresis is definitive therapy; typical volumes are 40 mL/kg in stable patients and up to 60 mL/kg in critically ill patients. Multiple sessions are often required. Monitor for hypocalcemia from citrate anticoagulation and rare dysrhythmias. Leukapheresis is preferred for hyperleukocytosis. ED clinicians may assist by establishing large-bore central access with caution due to bleeding risk.
Follow-up and disposition
Admission criteria Admit all patients with symptomatic hyperviscosity or evidence of bleeding or end-organ ischemia; ICU admission is indicated for hemorrhage, altered mental status, or acute myocardial infarction.
Discharge criteria Discharge only after definitive treatment of the underlying disorder and symptom resolution.
Issues for referral All patients require hematology consultation.
Key points Avoid diuretics as they can worsen viscosity. The hallmark triad consists of visual disturbances, bleeding, and neurologic symptoms. Early recognition and rapid viscosity reduction are critical to prevent irreversible end-organ damage.
Basics
Description Hyperviscosity syndrome is the clinical consequence of increased blood viscosity leading to impaired microcirculatory flow and reduced tissue oxygen delivery. As viscosity rises, greater cardiac output is required to maintain perfusion, yet oxygen delivery worsens because blood transit through the microcirculation slows. The classic clinical presentation is a triad of mucosal bleeding, visual disturbances, and neurologic symptoms.
Etiology Hyperviscosity results from elevation of cellular or acellular blood components. Acellular (protein) hyperviscosity is the most common cause (85–90%) and is usually due to increased gamma globulins from monoclonal gammopathies such as Waldenström macroglobulinemia and multiple myeloma; polyclonal gammopathies from rheumatologic disease are rare. Cellular hyperviscosity (10–15%) occurs with markedly increased blood cells, including erythrocytosis in polycythemia vera, extreme leukocytosis (>100,000) in acute or chronic leukemia, and severe thrombocytosis.
Diagnosis
Signs and symptoms The classic triad includes bleeding, visual changes, and neurologic dysfunction. Hematologic manifestations are most common and include epistaxis, gingival, rectal, or uterine bleeding, prolonged postprocedural bleeding, and pruritus. Ocular findings include blurred vision, diplopia, visual loss, and characteristic funduscopic changes such as the “link-sausage” appearance of retinal veins, retinal hemorrhages, exudates, microaneurysms, and papilledema. Neurologic symptoms include headache, dizziness, vertigo, ataxia, tinnitus, hearing loss, paresthesias, peripheral neuropathy, seizures, altered mental status, coma, and intracranial hemorrhage. Renal manifestations include hematuria, sterile pyuria, and nephritic or nephrotic syndromes. Cardiovascular findings may include angina, myocardial infarction, dysrhythmias, and heart failure. Dermatologic features include Raynaud phenomenon, livedo reticularis, palpable purpura, digital infarcts, and peripheral gangrene.
History Suspect hyperviscosity syndrome in patients with the classic triad, known immunoglobulin-producing disorders, or hypercellular hematologic diseases presenting with microvascular ischemia or cardiac decompensation.
Physical exam No pathognomonic findings exist; exam reflects end-organ involvement such as mucosal bleeding, petechiae, focal neurologic deficits, heart failure signs, or abnormal funduscopic findings.
Essential workup Assess for bleeding and end-organ ischemia. Measure serum or whole blood viscosity when available. Suspect the diagnosis when laboratory processing is difficult due to serum stasis or analyzer obstruction from viscous samples.
Diagnosis tests and interpretation
Laboratory Obtain CBC with differential to assess anemia, erythrocytosis, leukocytosis, or thrombocytosis; normocytic normochromic anemia is common. Peripheral smear may show rouleaux formation, a key diagnostic clue. Check electrolytes, BUN, creatinine, and glucose; renal dysfunction is common, and pseudohyponatremia or hypercalcemia may occur in multiple myeloma. Urinalysis may show proteinuria or hematuria. Obtain coagulation studies. Perform serum and urine protein electrophoresis. Serum viscosity measurement (when available) is diagnostic; normal relative viscosity is 1.4–1.8, and symptoms usually develop at ≥4 centipoise.
Imaging Head CT is indicated in patients with neurologic symptoms to exclude intracranial hemorrhage.
Differential diagnosis Platelet disorders, inherited or acquired coagulation factor deficiencies, liver disease, vitamin K deficiency, and disseminated intravascular coagulation.
Treatment
Prehospital Initiate IV fluid resuscitation in patients with bleeding or suspected hypovolemia.
Initial stabilization/therapy Rehydrate with isotonic saline. Bleeding or ischemia often does not respond to routine therapy and requires viscosity reduction. In patients with anemia and leukemia, avoid transfusion before plasmapheresis as it may worsen viscosity.
Emergency department management Provide supportive care and obtain early hematology consultation. Phlebotomy is a temporizing measure in severe cases with coma or seizures when plasmapheresis is not immediately available; remove 100–200 mL of whole blood and replace with isotonic saline, ideally after consultation, and is first-line in polycythemia vera. Plasmapheresis or leukapheresis is definitive therapy; typical volumes are 40 mL/kg in stable patients and up to 60 mL/kg in critically ill patients. Multiple sessions are often required. Monitor for hypocalcemia from citrate anticoagulation and rare dysrhythmias. Leukapheresis is preferred for hyperleukocytosis. ED clinicians may assist by establishing large-bore central access with caution due to bleeding risk.
Follow-up and disposition
Admission criteria Admit all patients with symptomatic hyperviscosity or evidence of bleeding or end-organ ischemia; ICU admission is indicated for hemorrhage, altered mental status, or acute myocardial infarction.
Discharge criteria Discharge only after definitive treatment of the underlying disorder and symptom resolution.
Issues for referral All patients require hematology consultation.
Key points Avoid diuretics as they can worsen viscosity. The hallmark triad consists of visual disturbances, bleeding, and neurologic symptoms. Early recognition and rapid viscosity reduction are critical to prevent irreversible end-organ damage.
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