A Randomized Controlled Pilot Study of Goal-directed Iron Supplementation of Anemic, Critically Ill Trauma Patients With Functional Iron Deficiency, With and Without Oxandrolone

The inflammatory response associated with traumatic critical illness rapidly induces a functional iron deficiency, characterized by hypoferremia, decreased transferrin saturation (TSAT), hyperferritinemia, and iron-deficient erythropoiesis (IDE). These derangements in iron metabolism are primarily related to upregulation of the iron regulatory protein hepcidin, which inhibits ferroportin-mediated release of iron from both duodenal enterocytes and macrophages. The resultant functional iron deficiency both contributes to intensive care unit (ICU) anemia and increases the packed red blood cell (pRBCs) transfusion requirement.

Treatment strategies for functional iron deficiency in critically ill patients may be divided broadly into (1) iron supplementation and (2) mitigation of the effects of hepcidin. The goals of treatment are to reverse the serum iron debt, eliminate IDE, improve anemia, and ultimately decrease pRBCs transfusions. Given that approximately 90% of critically ill trauma patients with an ICU length of stay (LOS) ≥ 7 days receive at least one pRBCs transfusion, any strategy that has even a modest impact upon the transfusion requirement is likely to improve overall health outcomes substantially.

Issues surrounding iron supplementation of critically ill patients include formulation, dose, route of administration, hepcidin antagonism, and mitigation of the complications of iron overload, particularly infection. Our first RCT of iron supplementation of critically ill surgical patients compared enteral ferrous sulfate 325 mg thrice daily to placebo (NCT00450177). Although a significant reduction in pRBCs transfusion requirement for the iron group was observed, low injury severity, intolerance of enteral medications, and a predominance of traumatic brain injury limited generalizability. In a second multicenter RCT, we compared intravenous iron sucrose 100 mg thrice weekly to placebo among critically ill trauma patients (NCT01180894, NTI-ICU-008-01) [8]. Iron supplementation using this generic dosing scheme did not impact the serum iron concentration, TSAT, IDE, anemia, or pRBCs transfusion requirement. Rather, iron supplementation accumulated as ferritin as evidenced by a significantly increased serum ferritin concentration in the iron as compared to the placebo group at all time points. Iron supplementation did not increase the risk of infection in either trial, despite a relatively high incidence of marked hyperferritinemia (serum ferritin concentration > 1,000 ng/mL) in the iron group.

The results of these trials suggest that iron supplementation alone, and using a generic dosing scheme, is ineffective. The current pilot trial aims to build upon the findings of the prior two RCTs by incorporating both goal-directed iron supplementation and hepcidin antagonism. The hypothesis is that the combination of goal directed iron supplementation and hepcidin mitigation will safely eliminate both the serum and bone marrow iron debt of anemic, critically ill trauma patients with functional iron deficiency.