Background: Hemorrhage is the leading cause of preventable death in traumatically injured civilian and military populations. Prehospital resuscitation largely relies on crystalloid and colloid intravascular expansion, as whole blood and component blood therapy are logistically arduous. In this experiment, we evaluated the bookends of Tactical Combat Casualty Care Guidelines recommendations of prehospital resuscitation with Hextend and whole blood in a controlled hemorrhagic shock model within non-human primates, as means of a multifunctional resuscitative fluid development.
Methods: In the nonhuman primate, a multiple injuries model was used, consisting of a musculoskeletal injury (femur fracture), soft tissue injury (15-cm laparotomy), and controlled hemorrhage to a mean arterial pressure of 20 mm Hg, demarcating the beginning of the shock period. Animals were randomized to prehospital interventions of whole blood or Hextend at T = 0 minutes, and at T = 90 minutes definitive surgical interventions and balanced sanguineous damage control resuscitation could be implemented. All animals were euthanized at T = 480 minutes. Data are expressed as mean ± SEM; significance, p < 0.05.
Results: No significant differences in survival (83% vs. 100%; p = 0.3), tissue perfusion (EtCO2 and StO2) or endpoints of resuscitation (base deficit, lactate, pH) between Hextend and whole blood were identified. Second, whole blood compared with Hextend demonstrated significantly earlier normalization of clot formation time, maximal clot firmness, and α angle.
Conclusion: A future multifunctional resuscitative fluid including an asanguineous, oncotic, non-oxygen-carrying component to facilitate intravascular volume expansion, and a component with synthetic coagulation factors and fibrinogen to deter coagulopathy may show equivalence to whole blood.
Level of evidence: N/A: Study type: translational animal model.