New injectable foam to treat battlefield wounds

An injectable foam system has been developed to stop profuse bleeding in wounded soldiers to boost their odds of survival in the battlefield.
Without prompt care, a badly wounded soldier can easily bleed to death while being transported to a distant medical station, researchers said.
Two traditional treatments - tourniquets and medicated gauze pads - often cannot stop the blood loss from a deep wound at the neck, shoulder or groin.
To give these soldiers a fighting chance at survival, Johns Hopkins University undergraduates have invented an injectable foam system designed to stop profuse bleeding from a wound where a limb or the head is connected to the torso.

The students' invention is designed to apply pressure and curb blood loss during the critical first hour during which a wounded soldier is moved to a site that provides more advanced medical help.
The new battlefield treatment is needed because a tourniquet or a gauze pad with a clotting agent are difficult to apply effectively to deep wounds at these junctional body sites.

In addition, the precise source of blood loss in such wounds is not always easy to find.
"The problem is that damage from bullets and bone fragments deep inside a junctional wound is not always visible from outside the body, and a regular clotting agent may not be able to reach the origin of the bleeding," said Sydney Rooney, leader of the biomedical engineering student team.

"We came up with a foam injection system that fills the wound area and blocks the blood loss," said Rooney.
She said the goal is to prevent wounded soldiers from losing more than half of their blood volume before they reach a medical facility.
The aim is to reach such a facility within 60 minutes, the so-called golden hour during which trauma care is most successful.
"The foam fills up the wound opening, hardens and applies pressure to the walls of the cavity," said Allie Sanzi, who participated in the project.
The two chemicals - a polyol and a diisocyanate - that produce the foam remain in canisters that are stored separately within the injector device before they are needed.

The students designed the canisters to keep the chemicals stable in military conditions at temperatures up to 38 degrees Celsius for at least one year.
The injector is about the size of a whiteboard marker. On the battlefield, the soldier administering the treatment would mix the two chemicals with a mechanism inside the injector.
Then, pushing down the plunger would insert the expanding foam into the wound to reduce bleeding.