JAMA Netw Open. 2019 Sep 4;2(9):e1912076

# Association of Early, High Plasma-to-Red Blood Cell Transfusion Ratio With Mortality in Adults With Severe Bleeding After Trauma.

Roquet F, Neuschwander A, Hamada S, Favé G, Follin A, Marrache D, Cholley B, Pirracchio R); Traumabase Group.

Importance: Optimal transfusion management is crucial when treating patients with trauma. However, the association of an early, high transfusion ratio of fresh frozen plasma (FFP) to packed red blood cells (PRBC) with survival remains uncertain.

Objective: To study the association of an early, high FFP-to-PRBC ratio with all-cause 30-day mortality in patients with severe bleeding after trauma.

Design, Setting, and Participants: This cohort study analyzes the data included in a multicenter national French trauma registry, Traumabase, from January 2012 to July 2017. Traumabase is a prospective, active, multicenter adult trauma registry that includes all consecutive patients with trauma treated at 15 trauma centers in France. Overall, 897 patients with severe bleeding after trauma were identified using the following criteria: (1) received 4 or more units of PRBC during the first 6 hours or (2) died from hemorrhagic shock before receiving 4 units of PRBC.

Exposures: Eligible patients were divided into a high-ratio group, defined as an FFP-to-PRBC ratio more than 1:1.5, and a low-ratio group, defined as an FFP-to-PRBC ratio of 1:1.5 or less. The ratio was calculated using the cumulative units of FFP and PRBC received during the first 6 hours of management.

Main Outcomes and Measures: A Cox regression model was used to analyze 30-day survival with the transfusion ratio as a time-dependent variable to account for survivorship bias.

Results: Of the 12 217 patients included in the registry, 897 (7.3%) were analyzed (median [interquartile range] age, 38 (29-54) years; 639 [71.2%] men). The median (interquartile range) injury severity score was 34 (22-48), and the overall 30-day mortality rate was 33.6% (301 patients). A total of 506 patients (56.4%) underwent transfusion with a high ratio and 391 (43.6%) with a low ratio. A high transfusion ratio was associated with a significant reduction in 30-day mortality (hazard ratio, 0.74; 95% CI, 0.58-0.94; P = .01). When only analyzing patients who had complete data, a high transfusion ratio continued to be associated with a reduction in 30-day mortality (hazard ratio, 0.57; 95% CI, 0.33-0.97; P = .04).

Conclusions and Relevance: In this analysis of the Traumabase registry, an early FFP-to-PRBC ratio of more than 1:1.5 was associated with increased 30-day survival among patients with severe bleeding after trauma. This result supports the use of early, high FFP-to-PRBC transfusion ratios in patients with severe trauma.