Association between length of storage of transfused red blood cells and multiple organ dysfunction syndrome in pediatric intensive care patients.
Red blood cells (RBCs) may be stored up to 42 days prior to transfusion. However, RBCs show many changes after storage including increased RBC aggregation, decreased 2,3-diphosphoglycerate levels, loss of RBC deformability, and loss of hemoglobin-nitric oxide regulation of vascular tone. Some studies suggest these storage changes in RBCs leads to poor clinical outcomes.
Gauvin and colleagues performed a secondary analysis of data from the Transfusion Requirements in Pediatric Intensive Care Units trial examining the association between red cell storage time and new or progressive multiple organ dysfunction syndrome (MODS). In the 455 patients evaluated, the storage time of 14 days or greater was associated with increased MODS; adjusted odds ratio, 2.23; 95% confidence interval, 1.20-4.15. Storage time greater than 21 days was associated with higher mortality (9.2% vs. 3.8%).
The most important potential limitation described by the authors is that sicker patients were transfused more frequently, which increased the probability that they receive blood stored for longer times. This bias could lead to over estimate of the risk of older blood.
A definitive answer to this important question will need to await the results of three ongoing clinical trials: Age of BLood Evaluation (ABLE), Age of Red blood cells In Premature Infants (ARIPI), and Red Cell Storage Duration Study (RECESS).
– Jeffrey L. Carson