Age of Blood as a Limitation for Transfusion: Potential Impact On Blood Inventory and Availability.

Evolving concerns about storage lesions for red blood cells (RBC) and their effect on patient outcomes have led to ongoing trials evaluating the benefits of transfusing fresher blood (less than 14 days) to acutely ill patients. If improved outcomes with fresh blood are clearly demonstrated, current inventory management strategies may have to be revisited.

We evaluated several RBC maximum shelf lives (MSLs) and their impact on RBC availability. First, we determined the average age of the RBC units in our inventory based on the ABO/Rh blood type by analyzing the data set of 18,987 RBCs transfused from April 08, 2008 to April 09, 2009. Secondly, we determined the feasibility of issuing RBC of designated age to patients using the same data set.

We found that 80% of the RBC inventory was delivered before 14 days of age (DoA), and that 42% versus 65% was issued before 14 DoA versus 21 DoA, respectively. RBC units spent on average 8.6 days on the shelf with a mean age at delivery of 10.2 days and a mean age at issue for transfusion of 18.8 days which varied depending on the ABO blood type as described in Table 1.

We then defined four scenarios where RBCs have different MSL: Scenario #1, #2, and #3 used a MSL of 7, 14, and 21 days, respectively. Scenario #4 used a combination of different MSLs depending on the category of patients, as follows: 7 days for 12% of patients (i.e., neonates), 14 days for 15% of patients (i.e., adult cardiovascular surgical patients), and 42 days for the 73% remaining patients receiving RBCs for transfusion. The simulations were performed using the original 18,987 data sets and results are summarized in Table 2 showing a significant decrease in the availability of RBC units by 51%, 20%, 10% and 0% for Scenario #1, #2, #3, and #4, respectively. Furthermore, the outdate rate would increase to 3.2%, 2.2%,1.0%, and 4.4% for the respective scenario.

Changing the maximum shelf life for red blood cell units will require novel approaches to RBC inventory management in order to meet hospital demands without risking a major shortage and putting patients at risk.

No relevant conflicts of interest to declare.