Evaluation of a novel hydrogel intravascular embolization agent in a swine model of fatal uncontrolled solid organ hemorrhage and coagulopathy.

Introduction: Current agents for the intravascular embolization of traumatic hemorrhage are used off-label and have been minimally studied with respect to their performance under differing coagulation conditions. We studied the hemorrhage control efficacy of a novel, liquid, polyethylene glycol-based hydrogel delivered as two liquid precursors that polymerize within the target vessel in a unique animal model of severe solid organ injury with and without dilutional coagulopathy.

Methods: Anesthetized swine (n = 36, 45 ± 3 kg) had laparotomy and splenic externalization.

Endovascular Embolization Techniques in a Novel Swine Model of Fatal Uncontrolled Solid Organ Hemorrhage and Coagulopathy.

Background: Endovascular embolization is increasingly used in treating traumatic hemorrhage and other applications. No endovascular-capable translational large animal models exist and coagulopathy's effect on embolization techniques is unknown. We developed a coagulation-adaptable solid organ hemorrhage model in swine for investigation of embolization techniques.

Abdominal aortic and junctional tourniquet versus zone III resuscitative endovascular balloon occlusion of the aorta in a swine junctional hemorrhage model.

Background: Junctional hemorrhage is a leading contributor to battlefield mortality. The Abdominal Aortic and Junctional Tourniquet (AAJT) and infrarenal (zone III) resuscitative endovascular balloon occlusion of the aorta (REBOA) are emerging strategies for controlling junctional hemorrhage, with AAJT currently available in select forward deployed settings and increasing interest in applying REBOA in the military prehospital environment. This study compared the hemostatic, hemodynamic, and metabolic effects of these devices used for junctional hemorrhage control.

Differing Resuscitation With Aortic Occlusion in a Swine Junctional Hemorrhage Polytrauma Model.

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) and Abdominal Aortic and Junctional Tourniquet (AAJT) have received much attention in recent as methods for temporary control of junctional hemorrhage. Previous studies typically used the animal's shed blood for resuscitation. With current interest in moving REBOA to prehospital environment, this study aimed to evaluate the hemodynamic and metabolic responses to different resuscitation fluids used with these devices.

Should Albumin be Considered for Prehospital Resuscitation in Austere Environments? A Prospective Randomized Survival Study in Rabbits.

Background: The new guidelines for prehospital care of combat casualties in shock recommend administration of whole blood or blood components to increase blood pressure to a permissible hypotensive level (i.e., hypotensive resuscitation [HR]).

Effect of partial and complete aortic balloon occlusion on survival and shock in a swine model of uncontrolled splenic hemorrhage with delayed resuscitation.

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is accepted as a resuscitation adjunct and bridge to definitive hemostasis. The ischemic burden of REBOA may be mitigated by a partial REBOA (P-REBOA) strategy permitting longer occlusion times and military use for combat trauma. We evaluated REBOA and P-REBOA in a swine multiple trauma model with uncontrolled solid organ hemorrhage and delayed resuscitation and surgical hemostasis.

Stability of Fibrinogen Concentrate in Human Blood Samples: An In Vitro Study.

Objectives: This study was designed to assess the stability and functional activity of fibrinogen concentrates subjected to the changes in temperature and duration observed in field conditions.

Methods: Fibrinogen concentrate was stored at -20°C (12 vials), 22°C (12 vials), and 50°C with 80% humidity (12 vials), for up to 6 mo. At each temperature, three vials of fibrinogen concentrate were taken out at 0, 1, 3, and 6 mo and reconstituted.

Double-blinded, placebo-controlled study of early tranexamic acid treatment in swine uncontrolled hemorrhage model.

Background: Tranexamic acid (TXA) is an antifibrinolytic drug that was shown to increase survival in trauma patients, but the mechanisms remain unclear. The purpose of this double-blinded, randomized placebo-controlled study was to determine if TXA with hypotensive resuscitation with Hextend (HEX) or fresh frozen plasma (FFP) reduced blood loss (BL) and improved survival in a model of uncontrolled hemorrhage.

Methods: Instrumented, anesthetized pigs (n = 11 per group) were subjected to 24-mL/kg controlled hemorrhage, followed by transection of the spleen.

Blood-banking techniques for plateletpheresis in swine.

During the past several years, trauma resuscitation in human patients has evolved from decreased use of crystalloids to increased use of blood products. Of high interest is the role of platelets in trauma resuscitation. Because conducting prehos- pital resuscitation in human trauma patients is very difficult, swine are often the animal model of choice for such studies because their coagulation and hemodynamic systems are similar to those in humans.

Comparison between human and porcine thromboelastograph parameters in response to ex-vivo changes to platelets, plasma, and red blood cells.

In the acute care setting, both the tracings and numeric outputs (R time, angle, and MA) of thrombelastography (TEG) may be used to inform treatment decisions. The objective was to determine the sensitivity of TEG to isolated changes in platelet count, hematocrit and fibrinogen concentration in human blood. As pigs have a similar coagulation system, we also compared the responses of the pig blood.

Stability of tranexamic acid after 12-week storage at temperatures from -20°c to 50°c.

Background: Tranexamic acid (TXA) is an antifibrinolytic agent that reduces blood loss during surgery, decreases mortality in civilian and military trauma populations, was adopted for prehospital use by the British military, and is now issued to U.S. Special Operations Forces for use on the battlefield.

Initial resuscitation with plasma and other blood components reduced bleeding compared to hetastarch in anesthetized swine with uncontrolled splenic hemorrhage.

Background: Damage control resuscitation recommends use of more plasma and less crystalloid as initial resuscitation in treating hemorrhage. The purpose of this study was to evaluate resuscitation with either blood components or conventional fluids on coagulation and blood loss.

Study Design And Methods: Isofluorane-anesthetized, instrumented pigs (eight per group) underwent controlled hemorrhage of 24 mL/kg, 20-minute shock period, splenic injury with 15-minute initial bleeding, and hypotensive fluid resuscitation.