How should iron deficiency be managed before surgery?

Management of Iron Deficiency Before Surgery

Preoperative iron deficiency should be detected and treated at least 4 weeks before elective surgery, with intravenous iron preferred for moderate-to-severe anemia or when surgery is scheduled within 2-3 weeks. 1

Screening and Evaluation

• Preoperative anemia affects 25-40% of patients undergoing major surgery and is independently associated with increased morbidity and mortality 1, 2
• Screening for anemia should be performed at least 4 weeks before elective surgery to allow time for evaluation and treatment 1
• Iron status assessment should include serum ferritin and transferrin saturation (TSAT) 1
• Iron deficiency is diagnosed when serum ferritin is <30 μg/L and/or TSAT <20% 1
• In the presence of inflammation (C-reactive protein >5 mg/L), serum ferritin <100 μg/L with TSAT <20% indicates iron deficiency 1

Treatment Algorithm

For Absolute Iron Deficiency (Ferritin <30 μg/L and/or TSAT <20%):

• Oral Iron Therapy:

  • Appropriate for mild-to-moderate anemia when surgery is scheduled 6-8 weeks away 2
  • Administer in divided doses (40-60 mg elemental iron daily or 80-100 mg on alternate days) 1
  • Limited efficacy in inflammatory conditions due to hepcidin-mediated inhibition of iron absorption 1

• Intravenous Iron Therapy:

  • Preferred for moderate-to-severe anemia 1, 2
  • Indicated when surgery is scheduled within 2-3 weeks 3, 4
  • Recommended in cases of oral iron intolerance, gastrointestinal uptake problems, or inflammatory conditions 1
  • Maximum hemoglobin increase typically observed 2 weeks after IV iron administration 3, 4
  • IV iron should be administered at least 10 days before surgery for optimal effect 4

For Functional Iron Deficiency (Ferritin 30-100 μg/L and TSAT <20%):

• Consider IV iron therapy, especially with concomitant inflammation 1
• Consider erythropoiesis-stimulating agents (ESAs) if no response to iron therapy alone 1

For Anemia of Chronic Disease (Ferritin >100 μg/L and TSAT >20%):

• Consider ESA therapy with iron supplementation 1
• Rule out other causes of anemia (vitamin B12/folate deficiency) 1

Specific Considerations

• Inflammatory Bowel Disease: IV iron is particularly indicated due to hepcidin-mediated inhibition of oral iron absorption 1
• Cardiac Surgery: Ultra-short-term combination treatment (IV iron, erythropoietin, vitamin B12, folic acid) one day before surgery can reduce transfusion requirements 5
• Orthopedic Surgery: IV iron (900 mg over 10 days) starting 4 weeks before surgery can increase hemoglobin by approximately 1.0 g/dL 3

Clinical Benefits of Treating Iron Deficiency

• Reduced need for perioperative blood transfusions 6, 5
• Decreased hospital length of stay (by approximately 2.8 days in one study) 6
• Improved postoperative physical rehabilitation 1
• Lower risk of postoperative complications 1, 2

Safety Considerations

• IV iron formulations have a low risk of serious adverse reactions (38 incidents per million administrations) 1
• Monitor for hypersensitivity reactions during and after IV iron administration 7
• Watch for symptomatic hypophosphatemia with IV iron carboxymaltose, particularly with repeated courses 7

Timing of Surgery

• If significant iron deficiency anemia is detected and cannot be adequately corrected, consider rescheduling elective surgery 1
• For optimal results, IV iron should be administered at least 10 days before surgery, with maximum hemoglobin increase typically observed after 2 weeks 3, 4