Hemostatic Evaluation of Refrigerated Whole Blood Stored 7 Days Post-Expiration

The United States Army has shifted doctrine to focus on large-scale combat operations against peer to near-peer adversaries. Future conflicts could result in a limited supply chain, leaving medical providers with only expired blood products for treatment of hemorrhagic shock. This study evaluated quality, function, and safety metrics of whole blood stored for 1 week past regulated expiration (i.e., 35 days, in CPDA-1).

Whole blood units (n = 6) were collected in citrate phosphate dextrose adenine-1 (CPDA-1) anticoagulant and stored refrigerated for up to 42 days. Units were sampled on days 35, 37, 39, and 42 of storage and evaluated for the following: complete blood count, blood metabolism and chemistries, clotting dynamics, and presence of bacteria.

The majority of evaluated parameters fell outside of normal clinical ranges beginning at day 35 of storage. At 42 days, blood pH was 6.58 ± 0.038, hemolysis was significantly increased (P = .037 vs day 35), and bacterial contamination was not evident. Glucose levels continuously dropped during extended storage. K+ was significantly increased at day 42 compared to day 35 (P = .010). A significant reduction in clot strength, factor V activity, and factor VIII activity was evident beginning at day 39 of storage.

Storage of whole blood out to 42 days results in a continuous decline in function, but further in vivo safety studies should be performed to determine if the benefits of expired blood outweigh the risks. Other methods to safely extend storage of whole blood that maintain hemostatic function and preserve safety should be investigated, with emphasis placed on methods that reduce potassium leak and/or hemolysis.