Platelet-To-Red Blood Cell Ratio and Clinical Outcomes Among Massively Transfused Trauma Patients.

INTRODUCTION: The association between the platelet-to-red blood cell (PLT:RBC) ratio and clinical outcomes in massively transfused trauma patients within the intensive care unit (ICU) remains unclear. This study aimed to evaluate the association. METHODS: This retrospective cohort study utilized the MIMIC-IV version 3.1 database. Trauma patients aged ≥16 y who were admitted to the ICU at hospital admission and received massive transfusion (total volume of red blood cells and plasma ≥2000 mL) within 24 h of ICU admission were included. These patients were stratified into the low-ratio (<1:5; n = 111) group and the high-ratio (≥1:5; n = 57) group based on the 24-h PLT:RBC volume ratio. The primary outcome was 28-d all-cause mortality. The secondary outcomes included blood product consumption, 28-d ICU-free and hospital-free days, and a composite adverse outcome (severe acute kidney injury, sepsis, or prolonged mechanical ventilation). RESULTS: A total of 168 patients were included. After adjustment, the high-ratio (PLT:RBC) transfusion strategy was not significantly associated with 28-d mortality (adjusted odds ratio, 1.59; P = 0.253), the composite adverse outcome (adjusted odds ratio, 1.62; P = 0.339), 28-d ICU-free days (adjusted mean difference, -2.14; P = 0.215), or 28-d hospital-free days (adjusted mean difference, -1.78; P = 0.164). Nevertheless, the high-ratio (PLT:RBC) transfusion strategy was significantly associated with a 33% reduction in total RBC consumption (adjusted ratio, 0.67; P < 0.001) and a 20% reduction in total blood product consumption during the ICU stay (adjusted ratio, 0.80; P = 0.037). CONCLUSIONS: The high PLT:RBC ratio transfusion strategy used in massively transfused trauma patients may be associated with lower blood product consumption but is not significantly associated with mortality or adverse outcomes.