Incidence of Expired Blood Product Use in the US Central Command Theater of Operations

Introduction: During multi-domain combat operations, logistical constraints may compel forward medical personnel to decide whether to use expired blood products. The incidence of expired blood product usage in recent conflicts is unknown.We queried the Armed Services Blood Program (ASBP) database of all blood administered in theater from 2002-2019. We categorized any administration of blood product with a transfusion date of 1-30 days after the expiration date for this analysis. We excluded any documented transfusions more than 30 days after the expiration date as likely represents clerical error based on study team experience.There were 1,491 (0.4% of the total transfusion dataset) units that met inclusion for this analysis. Of the 1,491, 86% (n=1,278 transfusions) will occur within 1-3 days post-expiration. These 1,491 units were transfused into 741 patients. The majority of expired blood product recipients were male (87%). Afghans were most frequent (46%), followed by US forces (22%) with most occurring during Operation Enduring Freedom (64%). Trauma was the most common mechanism of injury for these patients (70%). The most common blood type transfused to recipients was O positive (28%). The most frequently transfused expired unit was red blood cells (n=899), followed by platelets (n=299), followed by whole blood (n=152).Expired red blood cell and platelet use suggests a need for better methods for extending the lifespan of whole blood and further development of longer stability cold-stored platelets to meet the needs of our end-users. Our data arises from mature theaters during counterinsurgency operations. The incidence of transfusion of expired blood products may increase in future multi-domain operations where medical personnel are likely to operate under more resource constrained settings.