U.S. medical researchers say a new bandage made from shrimp shells will save lives on the battlefield.
The bandages are made of chitosan, which is known in China to promote healing. The Oregon company that produces them is called HemCon for "hemorrhage control."
Dr. Bill Weismann, a retired combat surgeon and a partner in the company says the bandage is an improvement over cotton gauze tourniquets, which have been used to treat combat wounds for centuries.
"We have pictures from the Trojan War that [show] a bandage very much like what our medics were using in the past, just a regular cotton bandage that was used to wrap around an injury," he said. "They don't stop bleeding."
The new bandage does, says Dr. Weismann, sealing even the forceful bleeding of a ruptured artery.
The HemCon partner says the chitosan bandage adheres to a wound, sealing off the blood flow. The U.S. Federal Drug Administration approved it last November.
Researchers at the Providence Saint Vincent Medical Center in Portland, Oregon, developed the product with funding from the Pentagon, which has ordered 27,000 of the bandages, 3,000 have been tested in Afghanistan and Iraq.
A Chinese-born researcher suggested the team investigate an old Asian remedy in its search for a clotting agent, and Dr. Kenton Gregory says the researchers followed that and other leads.
"We pulled every patent and publication that we could find for decades, and then we tried everything we could find that caused blood to clot," said Dr. Gregory. "We compared them all: Human protein, animal proteins, elements -stuff like iron sulfate- and some plastics. But the chitosan, it won. It was far superior in causing blood to instantly clot."
Chitosan also has an unexpected quality, it kills bacteria and discourages infection.
The new bandage feels like a sponge, and looks like pliable plastic, but it sticks to the skin when moistened. The physicians say that is why it stops bleeding so effectively.
Dr. Gregory said his company buys shrimp shells in bulk, and extracts the chitosan through a traditional process.
"We take shrimp shells and we boil them in lye or sodium hydroxide," he explained. "And then we purify them and crystallize them. We form a natural crystal out of the bandage. Then we put a plastic backing on it."
They add vinegar, which produces positive ions and makes the bandage more adhesive.
The researchers say other recent products have been developed to stop bleeding, one made of volcanic dust and another that uses human blood-clotting proteins. They say their chitosan bandages, at $90 apiece, are effective and less expensive than the alternatives.
Bill Weismann says the new bandage is primarily intended for combat. Injured soldiers can bleed to death in a matter of minutes, and the bandage will stabilize a wound for up to 48 hours. He adds that the product has other potential uses.
"In the civilian world, the bandage really has its application during surgery, where bleeding can occur in removal of a tumor or treatment of certain types of surgical illnesses, where there's a considerable amount of bleeding, such as bone surgery or brain surgery, for example," he said. "And we feel that the bandage will have a great impact on improving the control of bleeding during routine surgeries."
But for now, the chitosan bandages are being used to treat injuries on the surface of the body. The physicians say there are 70 million emergency room visits in the United States each year for bleeding injuries, and many patients could benefit from the bandage.
On the battlefield, they say, the bandage may one day be standard issue for troops, allowing injured soldiers to buy some extra time, while waiting for medical treatment in a combat zone.