Impact of blood transfusions on inflammatory mediator release in patients undergoing cardiac surgery

Study objectives: This study was conducted to investigate whether intraoper ative blood transfusions affect the release of proinflammatory mediators in patients undergoing cardiac surgery. Therefore, we measured plasma levels of bactericidal permeability increasing protein (BPI) as a marker of neutro phil activation, interleukin-6 (IL-6), lipopolysaccharide binding protein ( LBP), and C-reactive protein (CRP). In addition, these mediators, except CR P, were also measured in packed red cell units (PCs) administered to these patients. Design: Prospective study. Setting: Cardiopulmonary surgery department in a university hospital. Patients: One hundred fourteen consecutive patients undergoing cardiac surg ery. Interventions: Blood samples were taken at induction of anesthesia, at the start of aortic cross-clamping, at aortic unclamping, and at 0.5, 4, 8 , and 18 h thereafter. Results: Thirty-six patients received PC intraoperatively. BPI levels in pa tients who received transfusions were significantly higher at 0.5 and 4 h a fter aortic unclamping than in patients without transfusions (p < 0.05), an d increased with the number of PC administered. IL-6 levels at 0.5, 4, and 18 h after aortic unclamping were also significantly higher in patients who received transfusions (p < 0.01). BPI was found in all units of packed red cells tested at concentrations up to 15 times preoperative plasma levels i n patients. However, PC IL-6 could be detected in none of the samples. Plas ma levels of LBP and CRP were similar in both patient groups. LBP was found in very low concentrations in all PC. Patients who received intraoperative transfusions had a worse postoperative performance. Conclusions: Intraoperative PC transfusions do contribute to the inflammato ry response after cardiac surgery both by enhancing part of the response an d by directly changing plasma concentrations of inflammatory mediators. Fur thermore, these data show that intraoperative PC transfusion is associated with a worse postoperative performance.