Management of Erythrocytosis
Therapeutic phlebotomy should only be performed when hemoglobin exceeds 20 g/dL and hematocrit exceeds 65%, with associated symptoms of hyperviscosity and no evidence of dehydration. 1, 2
Diagnostic Approach
- Determine if erythrocytosis is primary (intrinsic defect in erythroid progenitors) or secondary (external factors stimulating erythropoiesis) 3, 4
- Evaluate for symptoms of hyperviscosity including headache, visual disturbances, fatigue, and poor concentration 2, 3
- Assess iron status through serum ferritin and transferrin saturation to evaluate the extent of erythrocytosis 2, 3
- Check peripheral blood smear to evaluate red cell morphology 3
Management Principles
First-Line Management
- Ensure adequate hydration as first-line therapy for all patients with erythrocytosis 2, 3
- Identify and treat underlying causes of secondary erythrocytosis (e.g., hypoxemia, sleep apnea, cyanotic heart disease) 3
- Avoid routine or repeated phlebotomies due to risk of iron depletion, decreased oxygen-carrying capacity, and increased stroke risk 1, 2
Indications for Therapeutic Phlebotomy
- Hemoglobin >20 g/dL and hematocrit >65% 1
- Presence of hyperviscosity symptoms (headache, fatigue, poor concentration) 1, 2
- Absence of dehydration or anemia 1
Phlebotomy Protocol
- Remove 1 unit of blood (400-500 mL) 1
- Always provide equal volume replacement with isotonic saline or dextrose solution 1, 5
- Administer replacement fluids simultaneously with blood removal to maintain intravascular volume 5
Special Considerations
Cyanotic Congenital Heart Disease
- Most cyanotic patients have compensated erythrocytosis with stable hemoglobin that requires no intervention 1
- Erythrocytosis is a physiological response to chronic hypoxemia to improve oxygen transport 1
- Monitor for hemostatic abnormalities which occur in up to 20% of cyanotic patients 1
Iron Deficiency Management
- Monitor iron status regularly in patients undergoing repeated phlebotomies 1, 3
- Iron deficiency in erythrocytosis can paradoxically worsen symptoms by reducing oxygen-carrying capacity and red cell deformability 1, 2
- Cautious iron supplementation with close monitoring of hemoglobin levels is recommended for patients with iron deficiency and erythrocytosis 3
Myeloproliferative Neoplasms
- In polycythemia vera, phlebotomy may be combined with cytoreductive therapy 1
- Consider low-dose aspirin if there are no contraindications, especially if secondary to myeloproliferative disorders 2
Alternative Treatments
- Erythrocytapheresis may be considered in selected cases where phlebotomy is not feasible 1
- Iron chelation therapy can be considered as a second-line option when phlebotomy is not possible, after careful risk-benefit assessment 1
Common Pitfalls to Avoid
- Performing routine phlebotomies without meeting established criteria (Hgb >20 g/dL, Hct >65%) 1, 2
- Creating iron deficiency through excessive phlebotomy, which can paradoxically worsen symptoms 1, 2, 3
- Performing phlebotomy in dehydrated patients, which can exacerbate hyperviscosity symptoms 5, 3
- Failing to provide equal volume replacement during therapeutic phlebotomy 1, 5