Fresh Frozen Plasma-to-Packed Red Blood Cell Ratio and Mortality in Traumatic Hemorrhage: Nationwide Analysis of 4,427 Patients.

Background: Despite the presence of highly reliable data, studies on packed red blood cells (pRBC):fresh frozen plasma (FFP) ratio suffer from limited sample size and the presence of survivor bias. We sought to study the association between FFP:pRBC and early mortality in the hemorrhaging trauma patient.
Study Design: This was a retrospective nationwide cohort that included all TQIP participating hospitals (2013 to 2016). We included all trauma patients who were transfused ≥10 pRBCs and ≥1 FFP within 24 hours. We excluded transferred patients and those who died in the emergency department or had missing/inaccurate transfusion data. Patients were assigned to 7 FFP:pRBC cohorts (range 1:1 to 1:6, and 1:6+) only if the ratio was similar at 4 and 24 hours and, to avoid survival bias, were excluded otherwise. Multivariable analyses correcting for all available confounders (age, demographics, comorbidities, vital signs, Injury Severity Score [ISS] and mechanism, procedures performed) were derived to study the independent relationship between FFP:pRBC and 24-hour mortality.
Results: Of 1,002,595 patients, 4,427 patients were included. Mean age was 41 years, 79% were males, 61% had blunt trauma, and median ISS was 29. Most patients were transfused in a 1:1, 1:2, or 1:3 ratio (31%, 41%, and 11%, respectively); mortality ranged between 28% for 1:1 and 62% for 1:4. In multivariable analyses, the odds of mortality independently and incrementally increased to 1.23 (95% CI 1.02 to 1.48) for a 1:2 ratio, 2.11 (95% CI 1.42 to 3.13) for 1:4, and as high as 4.11 (95% CI 2.31 to 7.31) for 1:5 (all p < 0.05).
Conclusions: A 1:1 FFP:pRBC ratio is associated with the lowest mortality in the hemorrhaging trauma patient, and mortality increases with decreasing ratios.
(Copyright © 2019 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)