Intravenous iron replacement for persistent iron deficiency anemia after Roux-en-Y gastric bypass

Background: Iron deficiency is a major postoperative complication of Roux-en-Y gastric bypass surgery. Oral replacement can fail to correct the deficiency. Thus, recourse to parenteral iron administration might be necessary. Our objective was to evaluate the effectiveness and safety of a standardized 2 g intravenous iron dextran infusion in the treatment of iron deficiency after Roux-en-Y gastric bypass surgery. The setting was a university-affiliated community hospital in the United States.

Methods: We reviewed the medical records of 23 patients at our institution who had received 2 g of iron dextran intravenously for recalcitrant iron deficiency after Roux-en-Y gastric bypass surgery. We obtained the demographic data and the complete blood count and serum iron studies obtained before treatment and at outpatient visits after infusion.

Results: Before treatment, all 23 patients were iron deficient (average ferritin 6 ng/mL) and anemic (average hemoglobin 9.4 g/dL). By 3 months, the average ferritin and hemoglobin had increased to 269 ng/mL and 12.3 g/dL, respectively. The hemoglobin levels remained stable throughout the follow-up period. The iron stores were adequately replaced in most patients. Four patients required a repeat infusion by 1 year, because the ferritin levels had decreased to <15 ng/mL. The probability of remaining in an iron replete state was 84.6% (95% confidence interval 78-91.2%). One patient required warm compresses for superficial phlebitis. No other significant adverse events were reported.

Conclusion: Intravenous administration of 2 g of iron dextran corrects the anemia and repletes the iron stores for ≥1 year in most patients. This therapy is safe, tolerable, efficient, and effective.