Autoresuscitation of Poloxamer 188 in Pigs With Traumatic Severe Hemorrhage.

Background: Poloxamer 188 (P188) is a copolymer surfactant with plasma membrane stabilizing action. This study investigated the effects of P188 on blood volume and coagulation in pigs after traumatic hemorrhage and hypotensive resuscitation.

Methods: Femur fracture was performed in 17 anesthetized pigs, followed by hemorrhage of 55% of estimated blood volume and a 10 min shock period.

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.

Exploring Tourniquet Conversion in Simulation to Develop Concepts and Hypotheses.

Background: Compared with those of tourniquet application, tourniquet conversion concepts are underdeveloped. The purpose of this project was to develop tourniquet conversion concepts and generate hypotheses.

Methods: One person performed 100 tests of tourniquet application and conversion.

Muscle deteriorations become prominent within 24 hours after admission in severely burned adults.

Background: Severe burn injury results in profound catabolic deterioration. Although burn-related catabolism has been well stated, it is unclear when the catabolic response begins. This study characterized acute changes of muscle protein breakdown at the admission and the day after in severely burned adults.

Minimal Effects of Intravenous Administration of Xenogeneic Adipose Derived Stem Cells on Organ Function in a Porcine 40% TBSA Burn Model.

Adipose stem cells (ASCs) have shown therapeutic promise for various conditions, including burn injury. While ASCs have immunomodulatory properties, concerns exist over pro-coagulant activity after intravenous (IV) administration. In the present study, we examined IV human ASC delivery in terms of coagulation, organ function, and inflammation in a 40% total body surface area (TBSA) swine burn model.

Role of albumin on endothelial basement membrane and hemostasis in a rat model of hemorrhagic shock.

Background: We sought to determine the extent of loss of endothelial basement membrane (BM), leukocyte recruitment, and changes in coagulation after hemorrhagic shock, followed by limited-volume resuscitation (LVR) with 5% albumin (ALB).

Methods: Anesthetized rats were bled 40% of blood volume and assigned to treatment groups: untreated (n = 6), LVR with normal saline (NS; n = 8), or LVR with ALB (n = 8). Sham rats (n = 6) underwent all procedures except hemorrhage or resuscitation.

Lessons Learned From the Battlefield and Applicability to Veterinary Medicine-Part 1: Hemorrhage Control.

In humans, the leading cause of potentially preventable death on the modern battlefield is undoubtedly exsanguination from massive hemorrhage. The US military and allied nations have devoted enormous effort to combat hemorrhagic shock and massive hemorrhage. This has yielded numerous advances designed to stop bleeding and save lives.

Effects of Donning and Wearing Personal Protective Equipment on Tourniquet Use and Conversion.

Background: We sought to gather data about the effects of personal protective equipment (PPE) use on tourniquet interventions by preliminarily developing a way to simulate delay effects, particularly on time and blood loss. Such knowledge might aid readiness. Field calls to emergency departments may indicate donning of PPE before patient arrival.

Distal organ inflammation and injury after resuscitative endovascular balloon occlusion of the aorta in a porcine model of severe hemorrhagic shock.

Background And Objective: Resuscitative Endovascular Balloon Occlusion of Aorta (REBOA) has emerged as a potential life-saving maneuver for the management of non-compressible torso hemorrhage in trauma patients. Complete REBOA (cREBOA) is inherently associated with the burden of ischemia reperfusion injury (IRI) and organ dysfunction. However, the distal organ inflammation and its association with organ injury have been little investigated.

Development and Validation of a Predictive Model for Hemodynamic Responses to Resuscitation during Uncontrolled Hemorrhage.

We investigated whether a statistical model could predict mean arterial pressure (MAP) during uncontrolled hemorrhage; such a model could be used for automated decision support, to help clinicians decide when to provide intravascular volume to achieve MAP goals. This was a secondary analysis of adult swine subjects during uncontrolled splenic bleeding. By protocol, after developing severe hypotension (MAP < 60 mmHg), subjects were resuscitated with either saline (NS) or fresh frozen plasma (FFP), determined randomly.

Albumin Saturated With Fatty Acids Prevents Decompensation in a Rat Hemorrhagic Shock Trauma Model With Tourniquet and Hypotensive Resuscitation.

Decompensation is a major prehospital threat to survival from trauma/hemorrhage shock (T/HS) after controlling bleeding. We recently showed higher than expected mortality from a combat-relevant rat model of T/HS (27 mL/kg hemorrhage) with tourniquet (TQ) and permissive hypotensive resuscitation (PHR) with Plasmalyte. Mortality and fluid requirements were reduced by resuscitation with 25% albumin presaturated with oleic acid (OA-sat) compared with fatty-acid -free albumin or Plasmalyte.

Burn resuscitation strategy influences the gut microbiota-liver axis in swine.

Fluid resuscitation improves clinical outcomes of burn patients; however, its execution in resource-poor environments may have to be amended with limited-volume strategies. Liver dysfunction is common in burn patients and gut dysbiosis is an understudied aspect of burn sequelae. Here, the swine gut microbiota and liver transcripts were investigated to determine the impact of standard-of-care modified Brooke (MB), limited-volume colloid (LV-Co), and limited-volume crystalloid (LV-Cr) resuscitation on the gut microbiota, and to evaluate its' potential relationship with liver dysfunction.

Conversion: Simulated Method of Exchanging Tourniquet Use for Pressure Dressing Use.

Background: Given little data to assess guidelines, we sought a way to exchange one type of intervention, field tourniquet use, for another, use of a pressure dressing. The study purpose was to test performance of controlling simulated bleeding with a stepwise procedure of tourniquet conversion.

Methods: An experiment was designed to assess 15 tests of a caregiver making tourniquet-dressing conversions.

Step Duration Effects on Blood Loss in Simulated Designs of Tourniquet Use Procedure.

Background: We sought new knowledge by further developing a model of using calculations in the simulation of a first-aid task. The purpose of this study was to develop the model to investigate the performance of tourniquet use in its component steps.

Methods: We aimed to design an experiment on a desktop computer by mathematically manipulating simulated data in tourniquet use.

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.

Efficacy of resuscitation with fibrinogen concentrate and platelets in traumatic hemorrhage swine model.

Background: This study compared the resuscitation effects of platelets and fibrinogen concentrate (FC) on coagulation and hemodynamics in pigs with traumatic hemorrhage and reduced platelet counts.

Methods: Thirty pigs (40 ± 3 kg) were anesthetized and catheterized with an apheresis catheter to remove platelets using the Haemonetics 9000 (Haemonetics, Braintree, MA). Afterward, a femur fracture was induced, followed by hemorrhage of 35% the estimated blood volume.

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.

Interoperable Readiness to Use Tourniquets by One's Familiarity With Different Models.

Background: We investigated interoperability for a first aid provider to perform simulated use of three tourniquet models of maximal, moderate, and minimal familiarity.

Methods: The experiment was focused on the tourniquets used by an expert who rendered aid on a manikin by using three models of tourniquet with different extents of familiarity: The familiarity with Combat Application Tourniquet (C-A-T) was maximal; that for Special Operations Forces Tactical Tourniquet (SOFTT) was moderate, and that for Military Emergency Tourniquet (MET) was minimal. Each model had a band-and-rod design.

Increased oxidative phosphorylation in lymphocytes does not atone for decreased cell numbers after burn injury.

The acute systemic inflammatory response syndrome (SIRS) and multiorgan dysfunction (MOD) that occur in large burn injuries may be attributed, in part, to immunosuppressive responses such as decreased lymphocytes. However, the mitochondrial bioenergetics of lymphocytes after severe burn injury are poorly understood. The purpose of this study was to examine mitochondrial function of lymphocytes following severe burns in a swine model.

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.

Plasma and Urinary Glycosaminoglycans as Evidence for Endotheliopathy in a Swine Burn Model.

Background: The endothelial glycocalyx controls vascular permeability, cellular signaling, blood-endothelial cell adhesion, extravasation, and transmission of shear stress signals. Burn injury compromises integrity of this layer increasing vascular permeability, which is further exacerbated by large volumes of (intravenous) crystalloids. We have shown that enteral resuscitation is able to reverse burn-induced acute kidney injury (AKI), and herein, we present a follow-up examination of the integrity of the glycocalyx layer and its relationship with renal dysfunction after burn injury.

Impact of oral resuscitation on circulating and splenic leukocytes after burns.

Background: Hemodynamic aberrations after severe burns are treated with aggressive intravenous (IV) fluid resuscitation however, oral resuscitation has been proposed in resource poor scenarios. Previously we have shown that animals receiving oral fluid following burns were able to recover kidney function. However, immune function such as circulating and splenic immune cell populations after oral or intravenous fluid administration was not examined.

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]).

Cremaster muscle perfusion, oxygenation, and heterogeneity revealed by a new automated acquisition system in a rodent model of prolonged hemorrhagic shock.

Local blood flow/oxygen partial pressure (Po) distributions and flow-Po relationships are physiologically relevant. They affect the pathophysiology and treatment of conditions like hemorrhagic shock (HS), but direct noninvasive measures of flow, Po, and their heterogeneity during prolonged HS are infrequently presented. To fill this void, we report the first quantitative evaluation of flow-Po relationships and heterogeneities in normovolemia and during several hours of HS using noninvasive, unbiased, automated acquisition.