From the Guidelines
Therapeutic phlebotomy is only recommended for patients with hemoglobin greater than 20 g per dL and hematocrit greater than 65%, associated with symptoms of hyperviscosity, such as headache or increasing fatigue, in the absence of dehydration or anemia 1. The management plan for a patient with elevated hemoglobin (high red blood cell count) should prioritize the reduction of blood viscosity and alleviation of symptoms.
- Key considerations include:
- Hemoglobin level: patients with hemoglobin greater than 20 g per dL are at increased risk of complications
- Hematocrit level: patients with hematocrit greater than 65% are at increased risk of complications
- Symptoms of hyperviscosity: headache, increasing fatigue, or other symptoms
- Phlebotomy should be performed with caution, removing 1 unit of blood and replacing it with an equal volume of dextrose or saline, to relieve hyperviscosity symptoms and improve coagulation 1. The goal of treatment is to reduce the risk of thrombotic complications and improve quality of life, while avoiding unnecessary interventions that may lead to iron depletion or decreased oxygen-carrying capacity.
- Regular monitoring of complete blood counts and serum ferritin or transferrin saturation is essential to track response to therapy and detect potential iron deficiency 1. It is crucial to address secondary causes of elevated hemoglobin, such as underlying lung disease or high-altitude exposure, and to maintain adequate hydration and avoid activities that could cause dehydration.
- Low-dose aspirin may be considered to reduce thrombotic risk, but this should be individualized based on the patient's specific condition and risk factors.
From the Research
Management Plan for Elevated Hemoglobin
The management plan for a patient with elevated hemoglobin (high red blood cell count) due to polycythemia vera (PV) involves several key components:
- Therapeutic phlebotomy to maintain a hematocrit level of less than 45% 2
- Low-dose aspirin to reduce the risk of thrombosis, unless contraindicated 2, 3
- Cytoreductive therapy with hydroxyurea or interferon for patients at high risk of thrombosis, such as those aged 60 years or older or with a prior thrombosis 2, 4, 3
- Ruxolitinib, a Janus kinase inhibitor, may be used to alleviate pruritus and decrease splenomegaly in patients who are intolerant of or resistant to hydroxyurea 2, 4, 3
Risk Stratification
Risk stratification is crucial in determining the management plan for patients with PV:
- Patients at high risk of thrombosis, such as those aged 60 years or older or with a prior thrombosis, require more aggressive management, including cytoreductive therapy 2, 3
- Patients with persistent PV symptoms may also benefit from cytoreductive therapy 2
Treatment Outcomes
Studies have shown that:
- Hydroxyurea is effective in reducing the risk of thrombosis and improving survival in patients with PV 5, 6
- However, approximately 24% of patients treated with hydroxyurea will eventually develop resistance or intolerance 4
- Ruxolitinib has been shown to be effective in controlling hematocrit and splenomegaly in patients with PV who fail or are intolerant to hydroxyurea 4, 3