Effect of Hemodilution on Coagulation and Recombinant Factor VIIa Efficacy in Human Blood In Vitro

Abstract : Hemorrhage and trauma are a major cause of death in young civilians and are the principal cause of death on the battlefield.1 3 In the United States, between the years 1997 and 2008, acute hemorrhage accounted for 30% of the overall mortality in trauma patients.3 Hemorrhagic shock and trauma followed by fluid resuscitation can lead to the development of coagulopathies that can complicate surgical attempts to stop the bleeding.1,4,5 The inability to clot can be caused by acidosis, hypothermia, and dilution of coagulating factors; all associated with hemorrhage and trauma.4,6,7 Of these three, hemodilution, resulting from after routine resuscitation with large volumes of crystalloid or colloid in an attempt to restore blood volume and blood pressure, is a problem that is often caused by the medical teams treating these patients. Hemodilution occurs. Currently, the Advanced Trauma Life Support protocol recommends resuscitation with 2 L of lactated Ringer s followed by packed red blood cells if the crystalloid fails to reverse the signs of shock.8,9 The military edition of the Prehospital Trauma Life Support recommends 1 L to 2 L of lactated Ringer s after hemorrhage is under control.10 Replacement of lost blood with 1 L to 2 L of nonplasma fluid represents (at least) a 30% to 40% dilution of blood volume in a 70-kg person,11 which could lead to dilution of clotting factors and a decrease in coagulation.