Another situation not discussed in the TCCC Guidelines that you may encounter as CPP-level providers is non-compressible torso hemorrhage (NCTH). This can be defined as high-grade injury present in one or more of the following anatomic domains: pulmonary, solid abdominal organ, major vascular or pelvic trauma; plus, hemodynamic instability or the need for immediate hemorrhage control.55 In these situations, the standard interventions for massive hemorrhage and circulation control that have been discussed do not have appreciable impact.56

NCTH may cause shock and death despite relatively unimpressive entrance wounds. Currently, the mainstays of treatment include administration of tranexamic acid (discussed in the next module), resuscitation with whole blood (which replaces losses, but does not affect ongoing continued losses), and rapid transportation to a facility where definitive surgical control of the hemorrhage can be achieved. Transport of a casualty with suspected NCTH should be accomplished on an emergent basis.57

Two newer technologies that may assist with NCTH control are Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) and ResQFoam™, an intraperitoneally injected polyurethane self-expanding foam.58

REBOA hemorrhage control is a developing field with new information being published continuously, so the intent of this discussion is to introduce the concept, and understand its indications and limitations. For a more complete understanding of REBOA, refer to the JTS clinical practice guideline Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for Hemorrhagic Shock (CPG ID:38).59, 60 REBOA can control NCTH using a less invasive option and with fewer physiologic disturbances compared with an invasive emergent thoracotomy for aortic cross-clamping.61

REBOA devices are inserted via the femoral artery, and consist of a catheter with an inflatable balloon. The catheter is passed retrograde up to the desired site of occlusion, and the balloon is inflated, stopping distal flow below the site of occlusion.62, 63 Traditionally, the procedure has been done mostly in medical treatment facilities under fluoroscopic guidance. But there have been use cases in more austere environments.64, 65, 66

REBOA is indicated in casualties exsanguinating from abdominal, pelvic, or junctional lower extremity bleeding who are not in cardiopulmonary arrest, and do not have exsanguinating hemorrhage in the chest.67 This determination may be suspected based on the mechanism of injury to the abdomen or pelvis, a blast or blunt injury with a positive focused assessment with sonography in trauma or suspected pelvic fracture, or massive proximal lower extremity trauma with signs of impending cardiovascular collapse.

But REBOA has significant limitations. These include:

- A contraindication in the setting of major thoracic hemorrhage or pericardial tamponade68
- The need for expedient access to definitive hemorrhage control (depending on the anatomic location of the device, there are time limits before ischemic damage is likely, ranging from 30-60 minutes)69, 70
- REBOA availability and provider training/experience71
- Lack of femoral vascular access72
- Tactical limitations (scene safety, room to maneuver, mass casualty considerations, etc.)

The evidence supporting the use of REBOA comes from retrospective systematic reviews of descriptive and qualitative studies, as well as subject matter expert consensus statements.

ResQFoam is one of a handful of agents being investigated that expand in the abdomen and tamponade sources of internal hemorrhage. It involves mixing and percutaneously injecting two liquid precursors into the peritoneal cavity. The resulting compound rapidly expands approximately 35-fold inside the abdomen and becomes a solid foam that conforms to the anatomy of the abdominal organs over a one-minute period. It is designed not to adhere to the abdominal organs and tissues, allowing for easier removal at surgery.73

Currently, neither ResQFoam, nor any similar product, is FDA approved; but it has been FDA approved for use in human clinical trials after successful results in animal models.74, 75

There are potential advantages of an expanding agent that controlled internal hemorrhage by tamponade. A wider range of medical personnel could be trained to use this intervention when compared to those who could be trained to perform REBOA. It would likely be more accessible at forward locations. The fact that it does not completely occlude distal flow would allow for longer times between application and definitive surgery, allowing for it to be used even if surgery may be delayed.76