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

Objective: To investigate the influence of blood derivatives on the acquisi tion of severe postoperative infection (SPI) in patients undergoing heart s urgery. 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 stu dy. We studied the influence of 36 variables on the development of SPI in g eneral and individually for pneumonia, mediastinitis, and/or septicemia. Th e influence of the blood derivatives on infections was assessed for RBC con centrates, RBC and plasma, and RBC and platelets. Results: Seventy patients (9.4%) were classified as having SPIs, and 668 (9 0.6%) were classified as having SPIs. After multivariate analysis, the vari ables associated with SPP (incidence, 9.4%) were reintubation, sternal dehi scence, mechanical ventilation (MV) for greater than or equal to 48 h, rein tervention, neurologic dysfunction, transfusion of greater than or equal to 4 U RBCs, and systemic arterial hypotension. The variables associated with nosocomial pneumonia (incidence, 5.9%) were reintubation, MV for greater t han or equal to 48 h; neurologic dysfunction, transfusion of greater than o r equal to 4 U blood components, and arterial hypotension. The variables as sociated with mediastinitis (incidence, 2.3%) were reintervention and stern al dehiscence, and those associated with sepsis (incidence, 1.6%) were rein tubation, time of bypass greater than or equal to 110 min, and MV for great er than or equal to 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-SPP 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, r espectively; p < 0.01) than those not transfused. Conclusion: The administration of blood derivatives, mainly RBCs, was assoc iated in a dose-dependent manner with the development of SPIs, primarily no socomial pneumonia.