Iron Content in One Unit of Packed Red Blood Cells
One unit of packed red blood cells (PRBCs) contains approximately 200-250 mg of elemental iron. 1
Detailed Iron Content Information
The iron content in PRBCs is well-documented in medical literature:
- According to the Journal of the National Comprehensive Cancer Network, one unit of PRBC (300 mL) typically contains 147-278 mg of iron 2
- The Journal of the American College of Cardiology reports that a unit of packed RBCs consists of 200 to 250 mg of elemental iron 2
- Praxis Medical Insights confirms that one unit of PRBCs contains approximately 200-250 mg of iron 1
Clinical Significance of Iron Content
Iron Accumulation with Multiple Transfusions
- The human body lacks an active excretion mechanism for iron, so transfused iron accumulates over time 2
- For pediatric patients, a transfusion of 15 mL/kg provides an estimated 8-12 mg/kg of iron 2
- Iron overload can develop after 20-25 units of blood transfusions 1
Transfusion Efficacy
- One unit of PRBCs typically increases hemoglobin by approximately 1 g/dL in an average-sized adult who is not actively bleeding 1
- Transfusion of 1 unit (300 mL) of PRBCs results in an average increase in hemoglobin level of 1 g/dL or hematocrit by 3% 2
Iron Overload Considerations
Iron from repeated transfusions can lead to significant clinical complications:
- Cardiac iron deposits (seen in approximately 60% of patients who receive >75 units) 1
- Liver damage with portal fibrosis 1
- Impaired cardiac left ventricular function 1
- Glucose intolerance and limited pituitary function 1
Monitoring and Management
- Consider iron chelation therapy in transfusion-dependent patients after approximately 25 units of red cells when serum ferritin exceeds 1000 ng/mL 1
- Monitor serum ferritin and transferrin saturation to assess iron overload 1
- Magnetic resonance imaging (T2*) can assess iron loading in the liver and cardiac tissue 1
Important Caveats
- The iron from transfused cells is not immediately available for erythropoiesis 1
- In inflammatory conditions, iron may take longer to be recycled due to sequestration in macrophages 1
- Storage duration affects iron availability and potential toxicity, with longer storage associated with increased extravascular hemolysis and non-transferrin-bound iron 3