Iron Replacement After Acute Hemorrhage
Start with oral iron as first-line therapy (35-65 mg elemental iron daily), but use intravenous iron for severe anemia, hemodynamic instability, or when rapid correction is needed before surgery. 1
Immediate Management Priorities
Hemodynamic Stabilization First
- Red blood cell transfusion is indicated for:
- For hemodynamically stable patients without acute coronary syndrome, maintain hemoglobin 7-9 g/dL 1
- Do not attempt to normalize blood pressure during active hemorrhage; use lower acceptable targets with volume resuscitation 1
Iron Replacement Strategy
Initial Therapy Selection
Oral Iron (First-Line for Stable Patients)
- Start with 35-65 mg elemental iron daily 1
- If inadequate response, increase to twice daily dosing 1
- If not tolerated, try alternate oral iron preparations 1
- Assess response at 1 month (hemoglobin rise ≥1.0 g/dL, normalization of ferritin and transferrin saturation) 1
Intravenous Iron (Preferred in Specific Situations)
- Use IV iron when: 1
- Oral iron is not effective, not absorbed, or not tolerated
- Presenting with severe anemia requiring rapid correction
- Need to increase hemoglobin acutely (prior to surgery or during pregnancy)
- Inability to maintain adequate hemoglobin despite frequent iron infusions
- Dosing approaches: 1
- Calculate total iron deficit using Ganzoni formula, OR
- Provide empiric total dose of 1 gram with interval reassessment
- Regularly-scheduled iron infusions may be needed unless chronic bleeding is halted 1
Critical Care Context Caveat
In critically ill patients specifically, IV iron is NOT routinely recommended unless combined with erythropoiesis-stimulating agents (ESAs), as it does not reduce transfusion requirements or improve mortality despite slightly increasing hemoglobin (+0.31 g/dL). 1, 2 This recommendation applies to the critical care setting, not to stable patients recovering from acute hemorrhage.
Monitoring and Follow-Up
Baseline Assessment
- Obtain iron panel: serum iron, total iron-binding capacity, serum ferritin, transferrin saturation 1
- Check hemoglobin, hematocrit, mean cellular volume 1
- Exclude acute phase reaction (C-reactive protein) to avoid false-negative results 3
Response Assessment
- Recheck at 1 month: hemoglobin should rise ≥1.0 g/dL with normalization of ferritin and transferrin saturation 1
- If inadequate response, evaluate for additional causes of anemia 1
- For long-term management, repeat basic blood tests every 6-12 months to monitor iron stores 3
Important Safety Considerations
Intravenous Iron Risks
- All IV iron formulations may cause: 2, 4
- Anaphylactoid reactions (0.65-0.7% for iron dextran)
- Hypotension, shortness of breath, chills
- Skin staining, hypophosphatemia
- Administration requirements: 2
- Only administer with staff trained to manage anaphylactic reactions
- Observe patients for at least 30 minutes post-infusion
- Iron sucrose has lower risk than iron dextran 1, 5
Contraindications and Cautions
- Avoid IV iron in patients with active infection (may promote bacterial growth and inflammation) 2
- Do not use long-term daily oral or IV iron supplementation when ferritin is normal or high (potentially harmful) 3
- In cancer patients receiving cardiotoxic chemotherapy, avoid concomitant IV iron administration 2
Duration of Therapy
Continue iron replacement for: 6
- 2 months to normalize hemoglobin
- Additional 2-3 months to build up iron stores
- Intermittent oral supplementation may be needed long-term to preserve stores in patients with recurrent deficiency 3
Special Populations
Functional Iron Deficiency
- Defined as ferritin <800 ng/mL AND transferrin saturation <20% 1
- IV iron has superior efficacy and should be considered for supplementation 1
- Data are insufficient to consider IV iron as monotherapy without ESAs 1