Life-saving Battlefield Tourniquet Approved for Use by Alabama First-Responders

The Abdominal Aortic Junctional Tourniquet™ (AAJT) that treats both pelvic hemorrhage and severe bilateral lower junctional hemorrhage has been approved for use by paramedics and other first-responders in Alabama.The AAJT, approved for military use in 2012 by the Federal Drug Administration (FDA), has saved many lives on the battlefield. Studies now show it also has applications for civilian populations and can assist emergency responders with patients who have massive, uncontrollable bleeding.

New research has shown that the AAJT capabilities are equivalent to Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in Zone 3 of the aorta which extends from the lowest renal artery to the aortic bifurcation. “REBOA can be life-saving in trauma patients, and now we have data that shows the AAJT is equivalent to this intervention,” says John Croushorn, MD, an emergency medicine physician and one of the inventors of the tourniquet. His company, Compression Works LLC, (compressionworks.com) is the developer and manufacturer of the device.

“The significance is remarkable,” he says. “The cost of the most popular REBOA kits is just less than $2,000, requires a physician to perform the procedure using ultrasound, and has similar risks to a cardiac catheterization. The AAJT costs about $500 and can be placed by anyone. No knowledge of anatomy is required and it does not involve the invasive risks of the REBOA procedure.”

This alternative use of the AAJT device was observed in 2013 by a British military physician who was using the tourniquet on a severely wounded soldier. As he monitored the patient’s end-tidal carbon dioxide (CO2) levels, the patient’s CO2 dropped to a morbidly low 16 percent. “When they put the AAJT device on the soldier, his CO2 increased to the normal level of 60 percent in 60 seconds,” Croushorn says. “That is one of REBOA’s effects, and we saw it before we even knew about REBOA.”

Jason Rall, PhD, Senior Research Scientist at CFD Research Corporation in San Antonio, TX, and his colleagues studied the REBOA and AAJT techniques for pelvic and high junctional injuries in the field. Their findings concluded that both the AAJT and Zone 3 REBOA were equivalent in the effects on cardiac output, systemic vascular resistance, and mean arterial pressure.

“They found no differences in peripheral capillary oxygen saturation (SpO2) and the partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio,” Croushorn says. “If the two interventions show the same survival, hemostatic, hemodynamic and metabolic profiles in multiple studies, why wouldn’t you use the alternative that is less invasive, less expensive, safer and quicker?”

Croushorn points out that the device, being equivalent to REBOA, enables paramedics to perform the same life-saving intervention at an accident scene that physicians would provide at a hospital. “The AAJT procedure provides a bridge mechanism to help get the patient to the hospital alive,” he says.

Another exciting study related to the AAJT was presented at the Military Health System Research Symposium recently. Researchers from the 59 Medical Wing of the Air Force in San Antonio examined the use of the AAJT in cardiopulmonary resuscitation (CPR) following cardiac arrest. “Traumatic cardiac arrest is a difficult problem, because standard CPR is ineffective,” Croushorn says.

The research showed the AAJT improved outcomes in a traumatic cardiac arrest model precipitated by Class IV hemorrhage and remained in arrest for three minutes before resuscitation was started. “It wasn’t just a subtle improvement,” Croushorn says. “A Kaplan-Meier survival analysis showed a survival rate of 83 percent with the AAJT application. Hemodynamically, carotid blood flow and carotid blood pressure increased with the tourniquet.”

Croushorn says he and other long-practicing physicians in his field don’t completely understand how this type of resuscitation can occur. “As a doctor who has done this for 20 years, I still don’t understand the physiologic capability of stopping all the blood flow through the aorta,” he says. “It is dramatic in the potential life-saving that can occur, and for a paramedic to have that resource inhand is amazing.”

Croushorn and his colleagues continue to study the capabilities of the AAJT and currently are working with the military to determine if a small revision in the tourniquet can treat non-compressible torso hemorrhage. They are also working with physicians in third world countries to ascertain the potential impact of the AAJT on post-partum hemorrhaging, a major cause of death in that part of the world.

Complications of the Abdominal Aortic and Junctional Tourniquet: What the research says

Tactical medics worldwide use the Abdominal Aortic and Junctional Tourniquet™ (AAJT) to
control hemorrhage from armpit, groin and pelvic injuries. Research over the last Zve years has
proven that the AAJT can effectively halt massive bleeding, and battleZeld experience shows that the device can save lives. But what about complications?

When applied to the abdomen, the AAJT compresses
the descending aorta to occlude blood ]ow to the pelvis
and extremities. Some medical professionals have
expressed concern that extended compression of the
abdomen can lead to bowel ischemia and other
problems. What do animal and human studies indicate?

According to Richard Schwartz, MD, co-inventor of the AAJT, research consistently shows that abdominal application is safe when used within the FDA-cleared application time of 60 minutes. In addition, at the inguinal or axillary application sites, the AAJT has the same 4-hour recommended application time as other junctional tourniquets.

“While recent papers identify potential complications after extended application of the device, these
studies actually reinforce the Znding that the AAJT is safe when used as indicated,” Dr. Schwartz said.
“Beyond that, the research also sheds light on how to think about the AAJT when making real-life ‘risk This article was developed by Trauma System News in cooperation with our advertiser,
Compression Works.“ AAJT abdominal placement (click to enlarge) versus beneZt’ decisions.”

Swedish military study

Recently, researchers funded by Swedish Defense examined the effects of prolonged abdominal
placement of the AAJT. Their Zndings were published online in the Journal of Trauma and Acute Care Surgery in July 2018.

In the study, 15 pigs were subjected to a class II hemorrhage. Five received the AAJT for 60 minutes and Zve received the device for 240 minutes (there was also a ]uid-only control group). Here are the key results:

  • The AAJT was hemodynamically and respiratorily tolerable for all animals in the study.
  • Animals in the 240-minute group showed signs of small intestine and liver ischemia, hyperkalemia, metabolic acidosis and other complications.
  • Animals in the 60-minute group displayed only minimal complications, and all consequences of reperfusion were reversible.

“In this study, there were really no substantial complications
associated with abdominal application of the AAJT up to one hour,”
Dr. Schwartz said. “After four hours of application, predictably, there
were complications. However, with any tourniquet, if you leave it on
long enough you will develop ischemia.”

These Zndings align with early tests of the AAJT. “In our preliminary
data, we began to see a rise in potassium after about 90 minutes of
application,” Dr. Schwartz said. “That’s why when we submitted our
premarket notiZcation to the FDA, we speciZed a 60-minute
application time when used on the abdomen for aortic occlusion.”

Although extended application led to signiZcant complications in this study, Dr. Schwartz noted that the survival rate was 100% in an intensive care setting. “They were actually able to resuscitate all the animals, even after 240 minutes of application.”

U.S. Army study

In a similar investigation, researchers from the U.S. Army Institute of Surgical Research studied
abdominal application of the AAJT for 60, 90 and 120 minutes. Their results were published online in the Journal of Surgical Research in June 2018. Here are the main Zndings:

  • All animals in the 1-hour group recovered full mobility within 1 week. Damage to muscle, nerve and
    intestinal tissue was insigniZcant or undetectable.
  • Half of the animals in the 1.5-hour group developed persistent hind leg paraplegia.
  • All animals in the 2-hour group developed persistent paraplegia and other complications.

“These results suggest that the timeframe where problems start to
develop is between 1.5 and 2 hours,” Dr. Schwartz said. “But this paper
essentially shows the same Znding as the Swedish study — at 60 minutes
of abdominal application the AAJT is safe.”

Dr. Schwartz believes the complications data should be viewed in relation to other interventions for massive bleeding. For example, a recent military study demonstrated that in terms of physiology, abdominal application of the AAJT is essentially equivalent to Zone 3 REBOA. “The complications associated with the AAJT after extended application are very similar to what we see with REBOA within these timeframes,” he said.

He also believes the data sheds light on the question of risks versus beneZts. “The AAJT is indicated for individuals with devastating injuries in situations where there really is no other means of controlling the hemorrhage,” Dr. Schwartz said. “In these situations, the choice may be between a dead casualty and a casualty with ischemic gut if application goes over 60 minutes.”

Future directions

“Every study shows that abdominal application of the AAJT is safe for 1 hour — in my opinion that question is answered,” Dr. Schwartz said. New research will examine just how far the window of safety extends. “We need to do more work to identify the ‘in]ection point’ where you begin to see irreversible ischemic change.”

Dr. Schwartz is Chairman of Emergency Medicine and Hospitalist Services at the Medical College of Georgia at Augusta University. He and his colleagues are now designing a study that will look at AAJT complications that emerge between 1 and 2 hours of abdominal placement.

Future studies may also investigate the AAJT as an intervention for unstable pelvis. “The AAJT is the only FDA-cleared solution for the prevention of shock in pelvic bleeding,” said John Croushorn, MD, co-inventor of the device. “So pelvic fracture is an area we have a lot of interest in.”

Other investigations could focus on the AAJT as an adjunct to resuscitation. A recent U.S. Air Force study suggests that abdominal application of the AAJT could dramatically increase survival for victims of traumatic cardiac arrest.

“The AAJT has the ability to improve cerebral perfusion during CPR, so we think it holds substantial potential for use in cardiac arrest and other resuscitation scenarios,” Dr. Schwartz said. “Overall, we think we are just beginning to scrape the surface on the potential applications of this device.”