From the Guidelines
Elevated RBC count requires therapeutic phlebotomy only when hemoglobin is greater than 20 g/dL and hematocrit is greater than 65%, associated with symptoms of hyperviscosity, as stated in the acc/aha 2008 guidelines 1. When evaluating an elevated RBC count, it is essential to consider the underlying cause and potential complications. The increase in red blood cell mass can lead to increased blood viscosity, which may cause symptoms such as headache and poor concentration 1. Key considerations for managing elevated RBC count include:
- Therapeutic phlebotomy is usually unnecessary unless the hemoglobin is more than 20 g/dL and the hematocrit is greater than 65% with associated symptoms of hyperviscosity and no evidence of dehydration 1.
- Repetitive phlebotomies should be avoided due to the risk of iron depletion, decreased oxygen-carrying capacity, and stroke 1.
- Iron deficiency, even in the face of erythrocytosis, is undesirable and requires careful management, including oral or intravenous iron supplementation 1. It is crucial to approach elevated RBC count with caution, considering the potential risks and benefits of therapeutic interventions, and prioritizing the patient's overall morbidity, mortality, and quality of life 1.
From the Research
Elevated RBC
Elevated red blood cell (RBC) count, also known as erythrocytosis, can be a symptom of various conditions, including polycythemia vera (PV) 2, 3, 4. PV is a myeloproliferative neoplasm characterized by an increased RBC mass and an increased risk of thrombosis.
Causes and Risk Factors
The exact cause of PV is unknown, but it is associated with a JAK2 gene variant in more than 95% of patients 2. Other risk factors for PV include advanced age, leukocytosis, and thrombosis 4.
Diagnosis and Symptoms
Diagnosis of PV is based on bone marrow morphology and the presence of JAK2 mutation 3, 4. Symptoms of PV may include pruritus, erythromelalgia, transient visual changes, and splenomegaly with abdominal discomfort 2.
Treatment and Management
Treatment of PV aims to prevent thrombohemorrhagic complications and typically involves therapeutic phlebotomy to maintain a hematocrit below 45% and low-dose aspirin 2, 3, 4. Cytoreductive therapy with hydroxyurea or interferon may be recommended for patients at high risk of thrombosis 2, 3, 4.
Complications and Prognosis
PV is associated with an increased risk of arterial and venous thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia 2, 3, 4. The median survival from diagnosis is approximately 14-27 years 2.
Phlebotomy and Thrombosis Risk
The need for frequent phlebotomies in patients with PV treated with hydroxyurea may indicate a higher risk of thrombosis 5. Patients requiring three or more phlebotomies per year had a significantly higher rate of thrombosis compared to those requiring fewer phlebotomies 5.
- Key points to consider:
- PV is a myeloproliferative neoplasm characterized by erythrocytosis and an increased risk of thrombosis
- JAK2 gene variant is present in more than 95% of patients with PV
- Treatment aims to prevent thrombohemorrhagic complications and typically involves therapeutic phlebotomy and low-dose aspirin
- Cytoreductive therapy may be recommended for patients at high risk of thrombosis
- Frequent phlebotomies may indicate a higher risk of thrombosis in patients with PV treated with hydroxyurea 2, 3, 4, 5