Abstract
The optimal transfusion ratios for severe blunt trauma requiring massive transfusion remain unclear. This nationwide retrospective cohort study used data from the Japan Trauma Data Bank (2019-2022) and included patients receiving ≥ 10 units of packed red blood cells (pRBC) within 24 h. The fresh frozen plasma (FFP)-to-pRBC and platelet concentrate (PC)-to-pRBC ratios were categorized as 0-0.5, 0.5-1, 1-1.5, 1.5-2, and > 2. Among 2,849 eligible patients, an FFP-to-pRBC ratio of 1-1.5 was associated with significantly higher in-hospital survival than 0.5-1 (adjusted odds ratio [OR], 1.46; 95% confidence interval [CI], 1.12-1.92; P = 0.006). A PC-to-pRBC ratio of 1.5-2 also showed a trend toward improved survival (1.62; 1.00-2.69; P = 0.053). Patients were categorized into three phenotypes: truncal trauma with shock (70.3%), moderate head and extremity trauma (11.8%), and severe head trauma with consciousness disturbances (17.9%). In the truncal trauma with shock phenotype, FFP-to-pRBC ratios of 1-1.5 (1.56; 1.12-2.20; P = 0.010) and > 2 (2.32; 1.14-5.10; P = 0.027) were associated with improved survival. Higher FFP-to-pRBC and PC-to-pRBC ratios may be associated with improved survival, especially in truncal trauma with shock.