Background : Techniques for better hemorrhage control after injury could change outcome. A large-animal model of lethal, uncontrolled hemorrhage was developed to test whether the use of various hemostatic agents would decrease bleeding and improve early survival.
Methods : A complex groin injury was created in 30 Yorkshire swine (42-55 kg) to produce uncontrolled hemorrhage. This injury included semitransection of the proximal thigh and complete division of the femoral artery and vein. After 5 minutes, the animals were randomized to (n = 6 animals per group) no dressing (ND), standard dressing (SD), SD and Rapid Deployment Hemostat (RDH) bandage, SD and QuikClot hemostatic agent (QC), or SD and TraumaDEX (TDEX). Limited volume 0.9% saline (1,000 mL over 30 minutes) resuscitation was started 30 minutes after injury. We measured blood loss, early mortality (180 minutes), and physiologic markers of hemorrhagic shock (e.g., cardiac output, blood pressure, hemoglobin, metabolic acidosis).
Results : Application of wound dressing decreased mortality in all groups compared with the ND group (83% mortality). However, this difference was significant (p < 0.05) only for the QuikClot hemostatic agent (0% mortality). Before the application of dressing (first 5 minutes), there were no differences in blood loss between the groups. After application of dressings, the QC group had the lowest blood loss (4.4 ± 1.4 mL/kg).
Conclusion : Of the hemostatic agents tested, QuikClot improved survival and decreased bleeding in a swine model of lethal vascular and soft tissue injury.
Uncontrolled hemorrhage is the leading cause of death in civilian and military trauma, 1 and effective hemorrhage control after injury could improve outcome. 2,3 Historically, approximately 20% of injured soldiers are killed in action, with 90% of the deaths taking place before reaching the field hospital. 4 When the source of bleeding is in the chest or abdomen, not much can be done in the battlefield to control the hemorrhage. In contrast, bleeding from an extremity injury can potentially be controlled by direct compression and application of dressing by the soldier him- or herself or the first responder. However, in a review of Vietnam War data, almost 40% of soldiers that died because of exsanguination had a source of hemorrhage that could have been controlled by simple hemostatic measures. 5
The ideal method for hemorrhage control should be suitable for application by a layperson, with effective control of bleeding from a variety of sources within minutes, and it should be associated with a low complication rate. The U.S. Military has invested considerable time and effort in this quest, and although a number of hemostatic agents have been identified, 6-8 no clear winner has emerged. In addition, most of the animal models that have been used to test hemostatic strategies do not simulate complex battlefield injuries, thus making their relevance questionable. 9 An area of increasing concern is lethal hemorrhage from sites that are not suitable for application of tourniquets or compression dressings (e.g., complex groin wounds), as seen during recent conflicts in Somalia and Afghanistan. This study defines a clinically relevant animal model of lethal hemorrhage from a complex groin wound and tests the efficacy of different hemostatic agents, in addition to standard dressing, on control of bleeding and improvement of early survival.