Massive transfusion in the trauma patient: Continuing Professional Development.

PURPOSE: Massive transfusion has recently been given a dynamic definition, namely, the replacement of more than four red cell concentrates within an hour. The purpose of this continuing professional development module is to review the pathophysiology of hemorrhagic shock in the trauma patient and the current management strategies of the massively bleeding trauma patient. PRINCIPAL FINDINGS: The massively bleeding trauma patient requires concurrent hemorrhage control and blood replacement therapy. Although there are many complications of massive transfusions, such as acid-base disturbances, electrolyte abnormalities, and hypothermia, perhaps the most difficult aspect to manage is acute trauma coagulopathy. Historically, coagulopathy was attributed to dilution of coagulation factors; however, recent accumulated evidence indicates that it is a multifactorial process associated with hypoperfusion, factor consumption, and hyperfibrinolysis. In an attempt to minimize acute trauma coagulopathy, massive transfusion protocols with equal ratios of red cell concentrates, frozen plasma, and platelets have been proposed. This type of hemostatic resuscitation, with near equal ratios of blood and blood products, has improved survival, but it is not without risk. In addition to the rapid and effective restoration of blood volume, the specific goal of transfusion management should be to maintain the patient's oxygen carrying capacity, hemostasis, and biochemistry. CONCLUSION: The current literature does not permit firm conclusions to be drawn regarding optimal transfusion ratios. It remains appropriate, however, to devise a massive transfusion protocol at the institutional level that provides treating physicians with rapid delivery of a reasonable initial ratio of products. This would permit patient-centred management with an emphasis on surgical control of bleeding, maintenance of normothermia, avoidance of electrolyte abnormalities, acid-base balance, and the timely delivery of blood products. OBJECTIVES: After reading this module, the reader should be able to: 1. Enumerate the complications associated with massive transfusion in the trauma context; 2. Understand how the coagulopathy present in the trauma patient differs from that seen in the elective setting; 3. Identify the modifications suggested by the recent literature for the management of massive transfusion in the trauma setting; 4. Appreciate the evidence for the institution of massive transfusion protocols.