Ratio-driven massive transfusion protocols

Abstract

Whole blood resuscitation was the primary treatment for hemorrhagic shock for half a century beginning with World War I. The development of blood separation techniques and component therapy was intended to improve blood availability and patient outcomes. However, these advances, in conjunction with theories about the need to replace extracellular fluid losses, resulted in the overuse of crystalloid and red blood cell (RBC) resuscitation, to the detriment of hemorrhaging patients for decades. As studies revealed higher ratios of plasma and platelet transfusions to RBCs were necessary to prevent and correct coagulopathy in traumatic hemorrhage, there was a return to proven strategies of the past, employing permissive hypotension, prompt surgical control of bleeding, and blood product resuscitation with component ratios approximating the composition of whole blood. Today, most institutions have adopted a massive transfusion protocol that employs whole blood approximation with a 1:1:1 or 1:1:2 ratio of platelet to plasma to RBC component transfusion. However, whole blood resuscitation has made a resurgence in recent years, and it may return as the product of choice for severe traumatic hemorrhage. Future studies are needed to determine the efficacy and safety of this pendulum swing, and many questions are still unanswered. However, continued inquiry and innovation remain in the quest for improved survival in traumatic hemorrhage.