Age of blood as a limitation for transfusion: potential impact on blood inventory and availability

Evolving concerns about storage lesions for red blood cells (RBCs) have led to ongoing trials evaluating the benefits of transfusing fresher blood to acutely ill patients.

We evaluated several RBC maximum shelf lives (MSLs) and their impact on RBC availability and outdate rate. First, we determined the mean age of the RBC units in our inventory by analyzing the data set of 18,987 nonirradiated RBC units transfused at our institution from April 2008 to March 2009. Second, we determined the feasibility of issuing RBC units of a designated age to patients using the same data set. We defined six scenarios where RBC units have different MSLs: Scenarios 1, 2, 3, 4, and 5 used a MSL of 7, 14, 21, 28, and 35 days, respectively. Scenario 6 used a combination of different MSLs depending on the category of patients.

RBC units spent on average 8.6 days on the shelf with a mean age of 10.2 days at delivery and 18.8 days at issue for transfusion. Using the original 18,987 data points, we observed a shortfall in the availability of RBC units, decreased by 51, 20, 10, 4, 1, and 0% and an increase in the outdate rate to 3.2, 2.2, 1.0, 0.6, 0.4, and 4.5% for Scenarios 1, 2, 3, 4, 5, and 6, respectively, compared to baseline.

Changing the MSL for RBC units would require novel approaches to RBC inventory management to meet hospital demands with acceptable outdate rates.