Efficacy of Uncross-Matched Type O Packed Red Blood Cell Transfusion to Traumatic Shock Patients: a Propensity Score Match Study

A new blood bank system was established in our trauma bay, which allowed immediate utilization of uncross-matched type O packed red blood cells (UORBCs). We investigated the efficacy of UORBC compared to that of the ABO type-specific packed red blood cells (ABO RBCs) from before the bank was installed. From March 2016 to February 2017, data from trauma patients who received UORBCs in the trauma bay were compared with those of trauma patients who received ABO RBCs from January 2013 to December 2015. Propensity matching was used to overcome retrospective bias. The primary outcome was 24-hour mortality, while the secondary outcomes were in-hospital mortality and intensive care unit (ICU) length of stay (LOS). Data from 252 patients were reviewed and UORBCs were administered to 64 patients. The time to transfusion from emergency room admission was shorter in the UORBC group (11[7-16] minutes vs. 44[29-72] minutes, P<0.001). After propensity matching, 47 patients were included in each group. The 24-hour mortality (4 [8.5%] vs. 9[13.8%], P=0.135), in-hospital mortality (14[29.8%] vs. 18 [38.3%], P=0.384), and ICU LOS (9[4-19] days vs. 5 [0-19] days, P=0.155) did not differ significantly between groups. The utilization of UORBCs resulted in a faster transfusion but did not significantly improve the clinical outcomes in traumatic shock patients in this study. However, the tendency for lower mortality in the UORBC group suggested the need for a large study.