Management of Iron Deficiency Before Surgery

Screening and Evaluation

Preoperative anemia affects 25-40% of patients undergoing major surgery and is independently associated with increased morbidity and mortality, according to the American Society of Anesthesiologists 1
Screening for anemia should be performed at least 4 weeks before elective surgery to allow time for evaluation and treatment, as recommended by the British Journal of Anaesthesia guidelines 2, 3
Iron status assessment should include serum ferritin and transferrin saturation (TSAT), with iron deficiency diagnosed when serum ferritin is <30 μg/L and/or TSAT <20%, according to the British Journal of Anaesthesia guidelines 2, 4, 5
In the presence of inflammation, serum ferritin <100 μg/L with TSAT <20% indicates iron deficiency, as stated by the World Journal of Emergency Surgery 6

Intravenous iron therapy is preferred for moderate-to-severe anemia, especially when surgery is scheduled within 2-3 weeks, and is recommended by the British Journal of Anaesthesia guidelines 2, 6
Oral iron therapy is appropriate for mild-to-moderate anemia when surgery is scheduled 6-8 weeks away, with a daily dose of 40-60 mg elemental iron, as stated by the World Journal of Emergency Surgery 6
IV iron should be administered at least 10 days before surgery for optimal effect, with maximum hemoglobin increase typically observed 2 weeks after administration, although the exact timing may vary 2, 6

For patients with inflammatory bowel disease, IV iron is particularly indicated due to hepcidin-mediated inhibition of oral iron absorption, as recommended by the Journal of Crohn's and Colitis and the World Journal of Emergency Surgery 6, 7
For patients with functional iron deficiency, consider IV iron therapy, especially with concomitant inflammation, as stated by the British Journal of Anaesthesia and the World Journal of Emergency Surgery 2, 6

Treating iron deficiency can improve postoperative physical rehabilitation, as stated by the Journal of Crohn's and Colitis 7
Treating iron deficiency can lower the risk of postoperative complications, according to the American Society of Anesthesiologists 1

IV iron formulations have a low risk of serious adverse reactions, with 38 incidents per million administrations, as reported by the World Journal of Emergency Surgery 6

The American College of Surgeons recommends intravenous iron infusion for patients with severe iron deficiency and recent blood loss requiring transfusion, with surgery scheduled in a short timeframe, as it can increase hemoglobin levels and reduce perioperative morbidity and mortality 8, 9
Severe iron deficiency, defined as a ferritin level below 30 ng/mL, is a strong indication for IV iron supplementation, as seen in patients with ferritin levels as low as 11 ng/mL 8, 10

IV iron administered at least 10 days before surgery can produce a mean hemoglobin increase of 8 g/L (0.8 g/dL) over 8 days, with reticulocytosis occurring at 3-5 days after administration 9
The use of IV iron can reduce perioperative blood transfusion requirements and improve postoperative outcomes, with a significant reduction in transfusion requirements 8, 9

IV iron has an excellent safety profile, with serious adverse reactions occurring in approximately 38 incidents per million administrations, most of which are complement activation-related pseudo-allergy 8, 9, 10
The risk of hypophosphatemia exists, especially with repeat dosing within 3 months, and serum phosphate levels should be monitored, particularly with ferric carboxymaltose 11

Correcting preoperative iron deficiency can reduce perioperative risk, with one study showing that postoperative IV iron reduced transfusion requirements and improved hemoglobin recovery 11
In critically ill patients, IV iron reduced hospital length of stay and 90-day mortality, highlighting the importance of iron supplementation in this population 11