A few retrospective clinical studies have reported poor outcomes after transfusion of older compared to fresh blood, suggesting the use of fresh blood, especially in cardiothoracic surgery. However, the design of some of these studies is poor, resulting in a low level of evidence in favor of the transfusion of blood stored less than 14 days.
In the present study, a guinea pig animal model was used to investigate the in vivo pathophysiology of fresh and stored RBC transfusions. Transfusion of old (28 days) but not of fresh blood resulted in intravascular hemolysis, acute hypertension, vascular injury and kidney dysfunction. The observed adverse effects were dramatically reduced when the high-affinity hemoglobin scavenger haptoglobin was given at the time of transfusion with blood stored for 28 days. The authors conclude that hemoglobin sequestration by haptoglobin might be a therapeutic option for optimizing transfusion safety in severely ill or massively transfused patients.
– Rainer Moog