Transfusion of blood components and postoperative infection in patients undergoing cardiac surgery.

OBJECTIVE To investigate the influence of blood derivatives on the acquisition of severe postoperative infection (SPI) in patients undergoing heart surgery. SETTING The postoperative ICUs of a tertiary-level university hospital. DESIGN A cohort study. METHODS During a 4-year period, 738 patients, classified as patients with SPIs and patients without SPIs (non-SPI patients), were included in the study. We studied the influence of 36 variables on the development of SPI in general and individually for pneumonia, mediastinitis, and/or septicemia. The influence of the blood derivatives on infections was assessed for RBC concentrates, RBC and plasma, and RBC and platelets. RESULTS Seventy patients (9.4%) were classified as having SPIs, and 668 (90.6%) were classified as not having SPIs. After multivariate analysis, the variables associated with SPI (incidence, 9.4%) were reintubation, sternal dehiscence, mechanical ventilation (MV) for > or = 48 h, reintervention, neurologic dysfunction, transfusion of > or = 4 U RBCs, and systemic arterial hypotension. The variables associated with nosocomial pneumonia (incidence, 5.9%) were reintubation, MV for > or = 48 h, neurologic dysfunction, transfusion of > or = 4 U blood components, and arterial hypotension. The variables associated with mediastinitis (incidence, 2.3%) were reintervention and sternal dehiscence, and those associated with sepsis (incidence, 1.6%) were reintubation, time of bypass > or = 110 min, and MV for > or = 48 h. The mortality rate (patients with SPI, 52.8%; non-SPI patients, 8.2%; p < 0.001) and mean (+/- SD) length of stay in the ICU (patients with SPI, 15.8 +/- 12.9 days; non-SPI patients, 4.5 +/- 4.4 days; p < 0.001) were greater for the infected patients. The transfused patients also had a greater mortality rate (13.3% vs 8.9%, respectively; p < 0.001) and a longer mean stay in the ICU (6.1 +/- 7.2 days vs 3.7 +/- 2.8 days, respectively; p < 0.01) than those not transfused. CONCLUSION The administration of blood derivatives, mainly RBCs, was associated in a dose-dependent manner with the development of SPIs, primarily nosocomial pneumonia.