An increasing number of institutions have demonstrated that a small portion of the trauma population will require a massive amount of blood products in a rapid fashion [21
]. In light of this, it is essential that trauma centers have an established mechanism to deliver these products quickly and in the correct amounts to these critically injured patients. Several authors have shown that a trauma exsanguination protocol (TEP) can be successfully implemented and have a significant positive impact on trauma outcomes [10••
]. DCR is a team effort that requires teamwork, communication, and collaboration. The goal is to organize a group of individuals to think and act as a team with a common goal [53
]. DCR evolved from the damage control surgery paradigm advocated by Stone et al.
] and Rotondo et al.
]. DCR involves the aggressive delivery of blood products which begins prior to any laboratory-defined anemia or coagulopathy [6
]. Damage control hematology defines the process of delivering large amounts of blood products (third component of DCR) in an efficient manner in patients who have been identified as having life-threatening hemorrhage [10••
To date, there are no prospective data informing clinicians of the optimal ratio of blood products for the massive transfusion trauma patient. Given the difficulty associated with performing a randomized controlled trial in a group of exsanguinating patients, several authors have attempted to define the optimal transfusion regimen in the absence of such a study design. Hirshberg et al.
] created a computer-based hemodilution model to simulate the exsanguinating patient and found that current resuscitation protocols severely underestimated the need for clotting factor replacement. On the basis of their findings, the authors recommended aiming for a ratio of plasma to red blood cells (RBCs) of 2 : 3 and a ratio of platelets to RBCs of 8 : 10. Ho and colleagues [61
] developed a mathematical model to simulate ACoTS and recommended the equivalent of whole blood be transfused. This ratio is similar to what has been proposed for DCR by the US military in the exsanguinating combat casualty [6
An exhaustive review of the literature demonstrated no class 1 data (and little class 2 evidence) describing the ideal ratio to transfuse to the trauma patient with exsanguinating hemorrhage [7
]. On the basis of what was available, however, ratios of at least 2 : 3 for plasma : RBC and 1 : 5 for apheresis platelets : RBC seemed justifiable and were implemented [10••
]. One group has found that patients receiving their massive transfusion protocol (plasma: RBC of 2 : 3 or greater and apheresis platelets : RBC of 1 : 5 or greater) have lower 30-day mortality when compared to patients receiving less than the prescribed ratios [13•
]. This was similar to what the Denver group found in a retrospective review of 133 patients [65
The clinical practice described by Beekley [31
] advocates transfusing on a 1 : 1 : 1 ratio, essentially trying to recreate the transfusion of whole blood. Duchesne et al.
] recently evaluated their experience of patients who required a massive transfusion at their urban level 1 trauma center. The authors found that those resuscitated with plasma to RBC ratio of 1 : 1 had a distinct survival advantage over those with a ratio of 1 : 4. Holcomb et al.
] recently reported their findings from a multicenter, retrospective study of 466 massively transfused civilian trauma patients. The authors demonstrated that patients receiving higher ratios (>1 : 2) of plasma and platelets to RBC had decreased truncal hemorrhage and increased survival at 6 h, 24 h, and at 30 days. In an evaluation of the German Trauma Registry, Maegele and colleagues [64
] evaluated outcomes in 713 critically injured patients who received a massive transfusion. They saw the greatest reduction in 24 h and 30-day mortality in the patients who achieved a high ratio of plasma to RBC. Sperry et al.
] recently evaluated 415 blunt trauma patients within the ‘Glue Grant’ database who received 8 units of RBC in 12 h. The authors demonstrated that in those patients who achieved a ratio of FFP : RBC greater than 1 : 1.5, a significantly lower mortality rate was observed in the first 48 h.