Therapeutic Phlebotomy Protocol for Erythrocytosis
Therapeutic phlebotomy should only be performed when hemoglobin exceeds 20 g/dL and hematocrit exceeds 65%, accompanied by symptoms of hyperviscosity such as headache, fatigue, or poor concentration, and in the absence of dehydration or anemia. 1
Indications for Therapeutic Phlebotomy
- Therapeutic phlebotomy is indicated when hemoglobin is greater than 20 g/dL and hematocrit is greater than 65% with associated symptoms of hyperviscosity 1
- Symptoms that warrant intervention include headache, increasing fatigue, and poor concentration 1
- Phlebotomy should not be performed in the presence of dehydration or anemia 1
- Pre-operative phlebotomy may occasionally be indicated to improve coagulation before elective surgery 1
Phlebotomy Protocol
- Remove one unit of blood (approximately 400-500 mL) per session 1
- Always replace with equal volume of isotonic saline or dextrose (750-1000 mL of isotonic saline) 1
- For patients with polycythemia vera, maintain hematocrit below 45% in men and at appropriate corresponding values for women and other races 1
- Target serum ferritin of 50 μg/L during induction phase, but not lower to avoid iron deficiency 1
Frequency and Maintenance
- During induction phase for patients with iron overload conditions like hemochromatosis, phlebotomy should be performed weekly or fortnightly until target levels are reached 1
- For maintenance phase in erythrocytosis, the frequency should be individualized based on the rate of red cell production 1
- Intervals between treatments vary by condition and individual response; monitoring is essential 2
Important Cautions
- Repeated routine phlebotomies are not recommended due to risk of iron depletion, decreased oxygen-carrying capacity, and stroke 1
- Iron deficiency, even with erythrocytosis, is undesirable as it reduces oxygen-carrying capacity, decreases red blood cell deformability (microcytes), and increases stroke risk 1
- Monitor for signs of iron deficiency through peripheral blood smear and serum ferritin or transferrin saturation 1
- In cyanotic congenital heart disease, aggressive phlebotomy should be avoided due to potential risk of stroke 1
Special Considerations
- For pregnant women with mild to moderate iron overload without advanced liver disease, phlebotomy can be paused during pregnancy in most cases 1
- In patients with congenital heart disease and cyanosis, judicious phlebotomy to a hematocrit level of 60% may be reasonable to alleviate hyperviscosity symptoms 1
- Erythrocytapheresis is an alternative to traditional phlebotomy and may be more effective at prolonging intervals between treatments 2
- For patients who cannot undergo phlebotomy, iron chelation therapy can be considered after careful risk-benefit assessment 1
Monitoring During Treatment
- Regular monitoring of hemoglobin, hematocrit, and iron status is essential 1
- Assess for symptoms of hyperviscosity before each phlebotomy session 1
- Monitor for signs of iron deficiency, which may require adjustment of phlebotomy schedule 1
- For patients with polycythemia vera, cytoreductive therapy should be considered in addition to phlebotomy for those at high risk for thrombosis 1, 3
By following these guidelines, therapeutic phlebotomy can be effectively used to manage erythrocytosis while minimizing complications associated with both the condition and its treatment.