Blood conservation in the critically ill

A multicenter, randomized clinical trial of IV iron supplementation for anemia of traumatic critical illness*

OBJECTIVE

To evaluate the efficacy of IV iron supplementation of anemic, critically ill trauma patients.

DESIGN

Multicenter, randomized, single-blind, placebo-controlled trial.

SETTING

Four trauma ICUs.

PATIENTS

Anemic (hemoglobin < 12 g/dL) trauma patients enrolled within 72 hours of ICU admission and with an expected ICU length of stay of more than or equal to 5 days.

INTERVENTIONS

Randomization to iron sucrose 100 mg IV or placebo thrice weekly for up to 2 weeks.

MEASUREMENTS AND MAIN RESULTS

A total of 150 patients were enrolled. Baseline iron markers were consistent with functional iron deficiency: 134 patients (89.3%) were hypoferremic, 51 (34.0%) were hyperferritinemic, and 64 (42.7%) demonstrated iron-deficient erythropoiesis as evidenced by an elevated erythrocyte zinc protoporphyrin concentration. The median baseline transferrin saturation was 8% (range, 2-58%). In the subgroup of patients who received all six doses of study drug (n = 57), the serum ferritin concentration increased significantly for the iron as compared with placebo group on both day 7 (808.0 ng/mL vs 457.0 ng/mL, respectively, p < 0.01) and day 14 (1,046.0 ng/mL vs 551.5 ng/mL, respectively, p < 0.01). There was no significant difference between groups in transferrin saturation, erythrocyte zinc protoporphyrin concentration, hemoglobin concentration, or packed RBC transfusion requirement. There was no significant difference between groups in the risk of infection, length of stay, or mortality.

CONCLUSIONS

Iron supplementation increased the serum ferritin concentration significantly, but it had no discernible effect on transferrin saturation, iron-deficient erythropoiesis, hemoglobin concentration, or packed RBC transfusion requirement. Based on these data, routine IV iron supplementation of anemic, critically ill trauma patients cannot be recommended (NCT 01180894).

Roles of Intravenous Iron Therapy in Various Patient Settings

Objective:

To provide clinical information on intravenous iron products and their role in chronic kidney disease (CKD), dialysis, oncology, critical illness, and heart failure.

Data Sources:

Intravenous iron products information, national clinical practice guidelines, and the latest primary literature available were reviewed. PubMed and MEDLINE databases were searched from January 2000-December 2009.

Study Selection and Data Extraction:

All FDA-approved intravenous iron products information, available national clinical practice guidelines, and primary literature were included.

Data Synthesis:

Iron deficiency is common in patients with CKD, dialysis, oncology, critical illness, and heart failure. Routine supplementation with intravenous iron therapy is indicated in patients with CKD, including those receiving dialysis; however, its role in oncology, critical illness, and heart failure is not clearly defined. Assessing patients for iron deficiency, evaluating their status, and knowing the risks of adverse events are important in determining the roles of intravenous iron therapy in each setting. If patients are initiated on intravenous iron, they must be closely monitored for signs and symptoms of adverse drug reactions, as well as clinical worsening. Additionally, intravenous iron must be discontinued upon resolution of iron deficiency.

Conclusions:

The importance of intravenous iron therapy is well established in patients with CKD, including those receiving dialysis, who have iron deficiency. Its roles in oncology, critical illness, and heart failure should be assessed on a case-by-case basis.

Randomized, double-blind, placebo-controlled trial of effects of enteral iron supplementation on anemia and risk of infection during surgical critical illness

BACKGROUND

Critical illness is characterized by hypoferremia, iron-deficient erythropoiesis (IDE), and anemia. The relative risks and benefits of iron supplementation in this setting are unknown.

METHODS

Anemic, critically ill surgical patients with an expected intensive care unit length of stay (ULOS) >or= 5 days were randomized to either enteral iron supplementation (ferrous sulfate 325 mg three times daily) or placebo until hospital discharge. Outcomes included hematocrit, iron markers (i.e., serum concentrations of iron, ferritin, and erythrocyte zinc protoporphyrin [eZPP]), red blood cell (RBC) transfusion, transfusion rate (mL RBC/study day), nosocomial infection, antibiotic days, study length of stay (LOS), ULOS, and death. Iron-deficient erythropoiesis was defined as an elevated eZPP concentration.

RESULTS

Two hundred patients were randomized; 97 received iron, and 103 received placebo. Socio-demographics, baseline acuity, hematocrit, and iron markers were similar in the two groups. No differences were observed between the iron and placebo groups with respect to either hematocrit or iron markers following up to 28 days. However, patients treated with iron were significantly less likely to receive an RBC transfusion (29.9% vs. 44.7%, respectively; p = 0.03) and had a significantly lower transfusion rate (22.0 mL/day vs. 29.9 mL/day; p = 0.03). Subgroup analysis revealed that these differences were observed in patients with baseline IDE only. Iron and placebo groups did not differ with respect to incidence of infection (46.8% vs. 48.9%; p = 0.98), antibiotic days (14 vs. 16; p = 0.45), LOS (14 vs. 16 days; p = 0.24), ULOS (12 vs. 14 days; p = 0.69), or mortality rate (9.4% vs. 9.9%; p = 0.62).

CONCLUSIONS

Enteral iron supplementation of anemic, critically ill surgical patients does not increase the risk of infection and may benefit those with baseline IDE by decreasing the risk of RBC transfusion. A trial comparing enteral and parenteral iron supplementation in this setting is warranted (ClinicalTrials.gov number, NCT00450177).