Association of leukocyte-depleted blood transfusions with infectious complications after cardiac surgery

Background: To test the hypothesis that leukocyte-mediated immunosuppression may contribute to postoperative infections after blood transfusions, we compared the incidence of postoperative infections in patients undergoing elective coronary artery bypass graft (CABG) surgery who received either leukocyte-depleted (LD-RBCC) or non-LD transfusions of red blood cell concentrates (RBCC) within 48 h of surgery. Materials and Methods: Data for all primary elective CABG patients between 1995 and 1998 who received allogeneic RBCC transfusions in the first 48 h after surgery were collected. Patients were divided into two groups (group LD: LD-RBCC transfusions only; group non-LD: non-LD-RBCC transfusions only were excluded). Patients who received a combination of LD and non-LD-RBCC transfusions, or any blood products other than RBCC were excluded. Infectious complications recorded included pneumonia, acute respiratory distress syndrome, mediastinitis, leg wound/sternal wound infection, nosocomial infection, catheter-related infection, urinary tract infection, decubitus ulcers, and bacteremia/fungemia. Results: One hundred forty-two patients received only LD-RBCC transfusions, and 1,765 patients received only non-LD-RBCC transfusions. Power analysis demonstrated that the sample size attained 80% power to detect an odds ratio of 2.1 at a significance level of p < 0.05. Infection rates were not significantly different between the non-LD and LD groups (7.57% vs. 9.52%, p = 0.40). Leukocyte depletion status of RBCC transfusions was not a predictor of infectious complications (p = 0.73). However, total units of RBCC received was highly associated with increased infection (p = 0.0001). Conclusions: No association between postoperative infections and the use of leukocyte-depleted blood was identified. However, an increased incidence of postoperative infections was observed to be associated with blood transfusions in general.