Effect of red blood cell transfusion on inflammation, endothelial cell activation and coagulation in the critically ill

BACKGROUND AND OBJECTIVES: Red blood cell (RBC) transfusion is a frequently applied intervention in an intensive care unit. However, transfusion is associated with adverse outcomes including organ failure and thrombo‐embolic events. Mechanisms of these effects are not known but may be related to activation of the endothelium or of the coagulation or inflammatory system. We hypothesized that a RBC transfusion in the critically ill would result in further activation of these systems. MATERIALS AND METHODS: In 74 non‐bleeding critically ill patients receiving one RBC unit, markers of inflammation, endothelial cell activation and coagulation were measured before transfusion, at 1 h after transfusion and 24 h after transfusion. The impact of disease severity of the recipient on these changes was assessed by comparing septic and non‐septic patients (according to sepsis‐3 definition) and by correlation of biomarkers with the sequential organ failure assessment (SOFA) score. RESULTS: Levels of von Willebrand Factor (vWF), soluble ICAM‐1, soluble thrombomodulin, fibrinogen and d‐dimer were already high at baseline, whereas ADAMTS13 levels were low. VWF levels increased significantly 24 h after RBC transfusion (median 478% (338–597) vs. 526% (395–623), p = 0.009). The other biomarkers did not change significantly. Post transfusion change was not dependent on the presence of sepsis and was not correlated with SOFA score. CONCLUSION: RBC transfusion in critically ill patients was associated with an increase in circulating vWF levels, suggesting a further increase in activation of the endothelium, a finding that was independent of the presence of sepsis or organ injury level.