The efficacy of red blood cell transfusion in the critically ill

In this thesis we investigated the post transfusion recovery (PTR) of a red blood cell (RBC) transfusion in critically ill patients and extended our knowledge on the clearance of RBCs during anemia of inflammation. Furthermore, we studied different potential pathways involved in transfusion related adverse events.
We found a high PTR of RBC transfusion in critically ill patients, mainly due to increased clearance of endogenous RBCs during inflammation. However PTR was lower in the most critically ill, indicating donor RBC clearance is correlated with disease severity. Therefore, the presence of inflammation probably plays an important role in the efficacy of RBC transfusion and has a large influence on the PTR.
Furthermore, in an sepsis animal model we found that RBC transfusion can be harmful during infection since bacteria can benefit from the extra iron, thereby washing of the RBC unit before donation could be an promising improvement. In the critically ill patient we showed that RBC transfusion results in higher circulating vWF levels, which is probably the result of an increase of endothelial activation. However, the clinical impact of the higher vWF levels seems limited. Thus, we did not find an obvious explanation for the higher incidence of transfusion related adverse events seen in critically ill patients and did not observe a direct correlation with the degree of inflammation.