Statistics gathered from military combat show that, of those who die from a traumatic injury in the battlefield, most perish within an hour. Medics refer to this critical interval as the "golden hour” where, with swift intervention, a person who appears gravely hurt can be saved. But what's even more crucial, they’ve found, is that the victim’s chance of survival may hinge on a first responder’s ability to minimize the loss of blood within the first 10 minutes.
"Hemorrhage is the leading cause of death on the battlefield," says Anthony Pusateri, of the Department of Defense Hemorrhage and Resuscitation Research and Development Program in a press release. "And one of our most challenging forms of hemorrhage has been junctional [the junction of the legs or arms with the torso] hemorrhage, or hemorrhage from deep wounds on which it is impossible to put a tourniquet or apply manual compression externally."
To meet this challenge, the company RevMedX has developed the patent-pending XStat—a syringe that, when injected directly into a gaping wound, creates a sealed barrier made up of tiny, pill-sized sponges. In tests on pigs, it took about 15 seconds for the device to bring a loss of blood to a halt.
Part of a project commissioned by the U.S. military, the company's original idea was to perfect a sprayable liquid foam that hardens on contact to help control instances of massive arterial bleeding, often caused by a bullet wound or stabbing. This approach, which worked much the same way Fix-a-Flat repair kits deliver sealant material into a punctured tire, was abandoned when researchers discovered that the substance, when applied, isn't able to withstand the pressure of blood streaming out. In their search for alternatives, they found that cellulose (wood pulp), with its super-absorbent properties, would be much more effective at stanching the difussive flow of blood.
“What's great about cellulose is that it's been around for decades and has good track record in the medical field," RevMedX vice president John Steinbaugh says. “But besides being sterile and safe to use, the big advantage with our version is that it can expand to 15 times its original size. So there's no need to apply pressure as it's already being applied on the inside as it expands."
Identifying a suitable material is one thing, figuring out a method for medical technicians to apply the dressing in a manner that's rapid, reliable and simple is another. For that, Steinbaugh credits students at Harvey Mudd College, who worked with RevMedX to fabricate a spongy material that’s coated with an antimicrobial clotting agent called chitosan. As the sponges soak up blood and expand within the wound, they clump together, becoming one firm mass that prevents excessive bleeding while similtaneously accelerating the clotting process. Addtionally, the sponges are individually marked with an "X" symbol that’s visible under x-rays, making it easy for surgeons to locate and remove them.
According to Steinbaugh, one pocket-sized applicator has the absorbent capacity of five large rolls of gauze. The company is also working on a slimmer version to handle cuts with narrow entry points and biodegradable sponges that gradually dissolve in the body. "If you can make the material absorbable by the body without any side effects, it makes things less complicated for the surgeon," he says, adding it would also be particularly effective for nosebleeds since the sponges could be left inside the cavity for several days.
Pending FDA approval, RevMedX hopes to make the XStat dressing available this summer.