New inflatable tourniquet designed to reduce battlefield deaths
By Bryan Clark
January 15, 2012
Insurgents are commonly taught to aim just below a soldier's body armor, which is where the abdominal area meets the legs. When a bullet hits this area it causes massive internal bleeding which often proves fatal in a matter of minutes. Two physicians specializing in emergency medicine have now developed a tool designed to treat rapid lethal war injuries. The device, which is known as the abdominal aortic tourniquet effectively slows bleeding and gives much needed time to stop the flow of blood which could save a soldier's life.
Dr. Richard Schwartz and Dr. John Croushorn, both having served in the military, developed the inflatable abdominal aortic tourniquet for use in combat situations after witnessing first-hand what kind of damage a well-placed bullet could do.
Before now, no instrument existed to combat this injury, so soldiers were often forced to compress the injury by pressing a knee into the mid-abdominal area to slow bleeding. This often did as much harm as good, as it slowed bleeding, but blocked the passage of blood to the legs.
"There is no way to put a tourniquet around it, so soldiers are getting shot in this area and dying within several minutes," said Dr. Richard Schwartz, Chairman of the Department of Emergency Medicine in the Medical College of Georgia at Georgia Health Sciences University.
Compressing the injury proves difficult due to the inability to compress the aorta from behind. The aorta runs parallel to the spine, so it can't be approached from the back and the injury is often several inches inside the abdomen of even the thinnest soldiers, which makes a traditional tourniquet all but useless.
The wedge-shaped device is designed to be wrapped around the abdomen and inflated via hand pump. Once inflated, the tourniquet slows blood flow by compressing the damaged blood vessels, giving the medical crew much-needed time to stop the bleeding.
"By effectively cross-clamping the aorta with the abdominal aortic tourniquet, you are essentially turning the faucet off," said Dr. John Croushorn, Chairman of the Department of Emergency Medicine at Trinity Medical Center in Birmingham, Alabama. "You are stopping the loss of blood from the broken and damaged blood vessels. You are buying the patient an additional hour of survival time based on blood loss."
Schwartz and Croushorn first tested the prototype device, which was funded by the U.S. Department of Defense, on pigs by inflating it to the point in which there was no blood flow from the aorta to the femoral arteries. Once blood flow was adequately restricted, they left the pigs constricted for an hour and documented the results. After an hour, they saw no potentially deadly increase in potassium levels in the blood and the tissue in the leg remained healthy. The next trial was on humans, albeit for a shorter duration, which yielded the same results.
The Food and Drug Administration (FDA ) has given premarket clearance for the abdominal aortic tourniquet and Schwartz and Croushorn have a manufacturer lined up. Currently they are receiving orders from the U.S. Military as well as law enforcement agencies worldwide.
Physicians are also interested in the product for its potential in helping CPR recipients. When giving CPR, the chest compression is designed to push blood away from the internal organs and into the extremities. This device may prove to be a more effective tool in achieving this goal.
"With this device, you could, in theory, double the blood flow to the kidneys, heart and brain," Schwartz said. Schwartz also believes the device could help focus drugs given during CPR to the location in which they are needed. "Now when a medic pushes a cardiac drug during cardiac arrest, the drug is circulated through the toes before it reaches steady state concentrations in the heart," Croushorn said.