ObjectiveTo evaluate the efficacy of a commercial immunoglobulin (Ig) A- and IgM-enriched immunoglobulin preparation containing high antibody titers against various human pathogens in the prevention of postoperative infections in anergic patients undergoing cardiac surgery.DesignA single-center, prospective, double-blind, randomized study comparing the effect of a polyvalent intravenous human immunoglobulin (IVIG) preparation vs. placebo.Location of the StudyInstitute of Anesthesiology and Department of Thoracic and Cardiovascular Surgery, University Hospital, Wurzburg, Germany.PatientsA total of 515 patients awaiting elective open-heart surgery with the aid of cardiopulmonary bypass were tested for their in vivo immune response to intradermally administered recall antigens. Forty patients who were preoperatively shown to be anergic in this skin test, and therefore at high risk of developing serious postoperative infections, were selected from this group. Twenty patients with normal immune responses, and thus having a normal risk of infection, were randomly selected from the same patient group to serve as an immunoreactive control group.InterventionsAfter obtaining approval from the local institutional review board and informed consent from patients, the 40 anergic patients were randomized and assigned either to the IVIG group (n = 19), to receive a commercially available human IgA- and IgM-enriched immunoglobulin preparation (dose, 20 g), or to the placebo group (n = 21), to receive physiologic saline. These treatments were started 4 hrs after surgery as a 400-mL continuous infusion over a period of 53 hrs. Patients were observed for the development of postoperative infection for the next 2 wks. Group comparisons were made using repeated-measures analysis of variance and Fisher's exact test. A p value < .05 was considered statistically significant.Measurements and Main ResultsPostoperative infections were detected in nine of 21 patients (43%) in the placebo group but in only one of 19 patients (5%) in the IVIG-treated group (p = .007; Fisher's exact test). Three of the 20 patients (15%) with normal immune response who received standard postoperative treatment developed postoperative infections.ConclusionsA commercially available IgA- and IgM-enriched intravenous immunoglobulin preparation administered immediately after cardiac surgery significantly reduced the incidence of postoperative infections in preoperatively anergic patients. (Crit Care Med;:)