Intravenous iron following cardiac surgery does not increase the infection rate

Intravenous iron (FeIV) has been used increasingly, alone or in combination with recombinant erythropoietin, to promote red cell production as part of a blood conservation program. Given the important role that iron plays in the growth of bacteria, it has been hypothesized that this use of FeIV may promote surgical site infection. However, this hypothesis has not yet been tested appropriately. To assess this hypothesis, postoperative infection rates in patients undergoing cardiothoracic surgery were analyzed.

Data were collected on 863 patients undergoing cardiopulmonary bypass surgery in 2001. Patients were either enrolled voluntarily in a blood conservation program in which they received either postoperative FeIV and erythropoietin (n=302), as indicated, or blood transfusions and no FeIV (n=561), as indicated, to correct postoperative anemia. Infections were defined according to the U.S. Centers for Disease Control and Prevention guidelines.

Thirty-nine infections developed. The overall infection rate was 4.52%, with an infection rate of 3.97% in the iron-treated group (n=12) and a rate of 4.81% in the untreated group (n=27). When the impact of gender, age, diabetes mellitus, operating time, type of surgery, and blood transfusions were controlled for, FeIV did not increase the risk of infection (odds ratio of 1.031 for each increment of 125 mg of FeIV; 95% confidence interval 0.908, 1.170; p=0.64).

There was no impact of FeIV on the subsequent infection rate in a cardiac surgery patient cohort, indicating its safety for use in the postoperative setting.