Phlebotomy for Polycythemia: Blood Volume Removal
For a patient with hemoglobin 17.3 g/dL and hematocrit 52.8%, therapeutic phlebotomy should remove 400-500 mL of blood with isovolumic replacement of 750-1000 mL of isotonic saline, but only if the patient has moderate to severe hyperviscosity symptoms, is not dehydrated, and is not iron deficient. 1
Clinical Context and Threshold for Intervention
Your patient's values (Hgb 17.3 g/dL, Hct 52.8%) do not automatically warrant phlebotomy. The critical decision point is whether symptoms are present:
- Therapeutic phlebotomy is indicated only when hematocrit exceeds 65% in the presence of moderate to severe hyperviscosity symptoms 1
- Your patient's Hct of 52.8% falls well below this threshold
- At 4000 meters altitude, these values would actually be within normal range (male Hct 45-61%, Hgb 13-21 g/dL) 2, though this likely doesn't apply to your patient
Critical Pre-Phlebotomy Assessment
Before considering any blood removal, you must exclude:
- Dehydration status - phlebotomy is contraindicated if dehydrated 1
- Iron deficiency - check MCV; if <80 fL, iron supplementation is needed instead of phlebotomy 1
- Hyperviscosity symptoms - headache, dizziness, visual disturbances, pruritus, erythromelalgia, or thrombotic events must be present and moderate to severe 1
Standard Phlebotomy Protocol (When Indicated)
If your patient meets criteria (Hct >65% with symptoms, no dehydration, no iron deficiency):
- Remove 400-500 mL of whole blood 1
- Simultaneously replace with 750-1000 mL of isotonic saline to maintain intravascular volume 1
- This isovolumic approach prevents hypotension and maintains hemodynamic stability 1
Common Pitfalls to Avoid
Do not perform routine phlebotomies to maintain predetermined hemoglobin targets - this practice causes iron deficiency, which paradoxically increases stroke risk through microcytosis 1. Inappropriate phlebotomies leading to iron deficiency were the strongest independent predictor of cerebrovascular events in cyanotic patients 1.
The severity of erythrocytosis alone is not a risk factor for thrombotic complications 1. Symptoms and underlying etiology matter more than the absolute number.
Alternative Considerations
Given that your patient's values don't meet guideline thresholds for phlebotomy:
- Investigate the underlying cause of the elevated hemoglobin (secondary vs. primary polycythemia, hypoxia, sleep apnea, smoking, renal pathology) 3
- If secondary erythrocytosis from hypoxia is identified, address the underlying cause rather than performing phlebotomy 3
- Consider observation with repeat measurements, as hemoglobin values naturally fluctuate ±1.4 g/dL over time 4
In summary, your patient with Hgb 17.3 and Hct 52.8% should not undergo phlebotomy unless they develop severe symptoms and their hematocrit rises above 65%. 1 Focus instead on identifying and treating any underlying cause of the mild elevation.