Half Phlebotomy vs Full Phlebotomy for Iron Lowering and HCT Reduction
No, half phlebotomy cannot achieve iron lowering and lower HCT better than full phlebotomy—standard full phlebotomy (500 mL) removes approximately 200-250 mg of iron per session, which is the established therapeutic standard, and reducing the volume proportionally reduces iron removal. 1
Volume-Iron Relationship
The iron removal achieved by phlebotomy is directly proportional to the volume of blood removed:
- One unit of blood (450-500 mL) contains 200-250 mg of iron, depending on hemoglobin concentration 1, 2
- Half phlebotomy (250 mL) would remove only 100-125 mg of iron per session, cutting therapeutic efficacy in half
- The iron content is determined by the erythrocyte iron concentration (approximately 787 μg/mL of packed red cells), meaning less blood equals proportionally less iron removed 3
Guideline-Recommended Approach
The American Association for the Study of Liver Diseases provides clear specifications:
- Weekly or biweekly removal of one full unit (500 mL) is the standard therapeutic protocol during the induction phase 1
- Hemoglobin/hematocrit should be checked before each phlebotomy, with the key safety parameter being that hematocrit should not fall by more than 20% from baseline 1, 2
- Target ferritin levels of 50-100 μg/L guide treatment endpoints, not the volume per session 1, 4
Safety Considerations for Volume Adjustment
If tolerability is a concern, the guidelines address this through frequency adjustment, not volume reduction:
- Patients who cannot tolerate weekly full phlebotomy should have treatments spaced to biweekly or less frequent intervals 1, 4
- If hemoglobin falls below 12 g/dL, decrease the frequency of phlebotomy, not the volume 2
- Patients with cardiac compromise may benefit from erythrocytapheresis (removing concentrated RBCs with less total blood volume processed) rather than half-volume phlebotomy 5
Alternative High-Efficiency Approaches
For patients requiring more efficient iron removal (not less):
- Erythrocytapheresis can remove 300-550 mL of concentrated RBCs (approximately 405 mg iron) in 12 minutes, achieving greater iron depletion per session with less total blood volume processed 5
- This approach reduces treatment duration by approximately 70% compared to standard phlebotomy, while maintaining safety 6
- This is recommended for severe iron overload requiring rapid depletion or patients with cardiac compromise 5
Clinical Pitfall to Avoid
Do not reduce phlebotomy volume below standard in an attempt to "go easier" on the patient—this only prolongs the treatment course (potentially 2-3 years for significant iron overload) and delays achievement of therapeutic targets 1, 2. Instead, adjust the frequency of full-volume phlebotomies based on hemoglobin recovery between sessions 1, 2.