From the Guidelines
Elevated hemoglobin levels above 20 g/dL with hematocrit greater than 65% require therapeutic phlebotomy to relieve symptoms of hyperviscosity, as recommended by the ACC/AHA guidelines 1.
Causes and Concerns
Elevated hemoglobin, also known as polycythemia, can be caused by various factors including low oxygen levels, bone marrow disorders, or other medical conditions. It is essential to determine the underlying cause to provide appropriate treatment. Elevated hemoglobin increases blood viscosity, which can lead to blood clots, stroke, and heart problems.
Treatment and Management
Treatment for elevated hemoglobin depends on the underlying cause. For severe cases, therapeutic phlebotomy is recommended to reduce blood viscosity and alleviate symptoms of hyperviscosity 1. Additionally, staying well-hydrated, avoiding tobacco and alcohol, and treating any underlying conditions are crucial. For secondary polycythemia caused by low oxygen levels, addressing the primary condition, such as sleep apnea or lung disease, is vital. For polycythemia vera, a bone marrow disorder, medications like hydroxyurea or interferon may be prescribed along with low-dose aspirin to reduce clotting risk.
Key Considerations
- Elevated hemoglobin levels can increase the risk of blood clots, stroke, and heart problems.
- Therapeutic phlebotomy is recommended for severe cases with hemoglobin levels above 20 g/dL and hematocrit greater than 65% 1.
- Treatment depends on the underlying cause, and addressing the primary condition is essential for secondary polycythemia.
- Medications like hydroxyurea or interferon may be prescribed for polycythemia vera, along with low-dose aspirin to reduce clotting risk.
From the Research
Elevated Hemoglobin and Polycythemia Vera
Elevated hemoglobin levels are a key characteristic of polycythemia vera (PV), a myeloproliferative neoplasm that affects approximately 65,000 people in the US 2. The condition is associated with an increased risk of thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia.
Diagnostic Criteria
The World Health Organization's major diagnostic criteria for PV include:
- Elevated hemoglobin or hematocrit level
- Abnormal results on bone marrow biopsy
- Presence of the Janus kinase 2 genetic mutation, which is present in approximately 98% of cases 3
- Subnormal erythropoietin level, which helps differentiate PV from common causes of secondary erythrocytosis such as smoking, sleep apnea, and testosterone use 3
Treatment Options
Treatment options for PV include:
- Therapeutic phlebotomy to reduce hematocrit levels to less than 45% 2, 4
- Low-dose aspirin to reduce the risk of thrombotic events 2, 3
- Cytoreductive therapy, primarily with hydroxyurea, to reduce the risk of thrombosis and improve quality of life 2, 5, 6
- Second-line agents such as pegylated interferon-alfa, busulfan, and ruxolitinib, depending on the clinical scenario 5, 6, 3
Management of Hydroxyurea Resistant or Intolerant PV
For patients who are resistant or intolerant to hydroxyurea, alternative treatment options include: