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.