Blood product use in trauma resuscitation: plasma deficit versus plasma ratio as predictors of mortality in trauma

BACKGROUND: Resuscitation of rapidly bleeding trauma patients with units of red blood cells (RBCs) and plasma given in a 1: 1 ratio has been associated with improved outcome. However, demonstration of a benefit is confounded by survivor bias, and past work from our group has been unable to demonstrate a benefit. STUDY DESIGN AND METHODS: We identified 438 adult direct primary trauma admissions at risk for massive transfusion who received 5 or more RBC units in the first 24 hours and had a probability of survival of 0.010 to 0.975. We correlated survival with RBC and plasma use by hour, both as a ratio (units of plasma/units of RBC) and as a plasma deficit (units of RBC - units of plasma) in the group as a whole and among those using 5 to 9 and more than 9 units of RBCs. RESULTS: Resuscitation was essentially complete in 58.3% by the end of the third hour and 77.9% by the end of the sixth hour. Mortality by hour was significantly associated with worse plasma deficit status in the first 2 hours of resuscitation (p < 0.001 and p < 0.01) but not with plasma ratio. In a subgroup with a Trauma Revised Injury Severity Score of 0.200 to 0.800, early plasma repletion was associated with less blood product use independently of injury severity (p < 0.001). CONCLUSIONS: 1) The efficacy of plasma repletion plays out in the first few hours of resuscitation, 2) plasma deficit may be a more sensitive marker of efficacy in some populations, and 3) early plasma repletion appears to prevent some patients from going on to require massive transfusion.