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Ganzoni Equation for Iron Deficiency Anemia
Estimates total body iron deficit to guide intravenous iron repletion dosing.
Ganzoni Equation for Iron Deficiency Anemia
Body weight
Actual (measured) hemoglobin
Target hemoglobin
Complete the fields above to see the result.
When to use
- Calculating the cumulative intravenous iron dose needed to correct iron-deficiency anemia.
Formula
Total iron deficit (mg) = body weight (kg) x [target Hb - actual Hb] (g/dL) x 2.4 + depot iron. Depot iron = 500 mg if weight >=35 kg, or 15 mg/kg if weight <35 kg.
Pearls and pitfalls
- The constant 2.4 derives from a blood volume of ~7% of body weight and ~3.4 mg iron per gram of hemoglobin.
- Divide the total deficit by the iron content per mL/vial of the chosen IV iron product to determine number of doses; most products cap the single-session dose.