Association of bacterial infection and red blood cell transfusion after coronary artery bypass surgery

Background. Previous studies have shown an association between red blood cell transfusions (RBC) and bacterial infections following coronary artery bypass graft (CABG) surgery. We sought to assess whether there is an independent effect of RBC on the incidence of bacterial infections. Methods. This was a prospective cohort study of 533 CABG patients over a 7-month period. Subjects were followed from time of CABG until 30 days postoperatively. Data were collected on patient and treatment characteristics, surgical management, and transfusion incidence. Results. Seventy-five (14.1%) of 533 patients developed a bacterial infection. After controlling for patient and disease characteristics, invasive treatments, surgical time, and the transfusion of other substances, the adjusted rate,; of bacterial infection were 4.8% for no RBC transfusion, 15.2% with one to two units, 22.1%. with three to five units, and 29.0% with greater than or equal to six units, (P-trend < 0.001). Diabetes was the only patient or disease factor significantly associated with bacterial infection (p < 0.001). Conclusions. RBC transfusions were independently associated with a higher incidence of post-CABG bacterial infections. The risk of infection increased in proportion to the number of units of RBC transfused. (C) 2002 by The Society of Thoracic Surgeons.