The influence of homologous blood transfusion on immunity and clinical outcome in aortic surgery

Abstract

Objectives: to evaluate the influence of homologous blood transfusion on immune responses and post-operative morbidity in aortic surgery. Design: analysis of the effects of homologous blood transfusion in 128 patients in a prospective randomised trial evaluating homologous and autologous blood transfusion in aortic surgery. Materials and methods: blood sampled before and at five times after surgery was assayed for C-reactive protein (CRP), neutrophil elastase, TNF-α and IL-6. Transfusions, morbidity and mortality were recorded; factors associated with poor outcome were identified by logistic regression. Results: homologous transfusion during surgery was required in 32 patients and precipitated an increase in neutrophil elastase (p = 0.008) and TNF-α (p = 0.015) but not IL-6 and CRP. Elastase peaked early in transfused patients at 41.27 (13.92-52.11) Δng/ml by 2 h compared to a peak of 21.51 (10.64-31.13) Δng/ml by 24 h in those who were not transfused. TNF-α peaked at 1.2 (0-4.33) Δpg/ml by wound closure in transfused patients and at -0.1 ( -2.05-2.52) Δpg/ml by 2 h without transfusion. Intra-operative homologous transfusion was associated with increased mortality (p = 0.01) and prolonged intensive care stay (p = 0.03). Mortality increased with age (p = 0.003) and was inversely related to the CRP peak (p = 0.007). Prolonged surgery predicted post-operative complications (p = 0.025). Conclusion: homologous transfusion increased the inflammatory response to aortic surgery and was associated with mortality.