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At a recent conference of the Army's Combat Casualty Care Program, Army doctors praised the effectiveness of a new super bandage that's currently only available to soldiers. The secret behind them? Shrimp shells.
The movie "Black Hawk Down" told the story of the October 3, 1993 mission in Somalia where nearly 100 U.S. Army Rangers were dropped by helicopter into the capital city of Mogadishu to capture two top lieutenants of a Somali warlord. Army surgeon LTC John Holcomb was one of only two field surgeons in Mogadishu who performed life-saving surgical procedures for 36 consecutive brutal hours after the engagement.
"War has always generated problems and solutions," says Holcomb, who is now commander of the US Army Institute of Surgical Research (USAISR) and chief of the trauma division at Brooke Army Medical Center in Texas. And so he's on a new mission, to help decrease blood on today's battlefields, where hemorrhaging is still one of the highest causes of death. To that end, he's been working with bandages that are laced with a mixture of ground shrimp shells and vinegar, a concoction that has been found to clot blood instantly.
A wounded soldier is transported in Mogadishu. image: LTC John Holcomb
"I got involved out of my experiences in Somalia in 1993 with soldiers who were bleeding," says Holcomb. "As an army surgeon I found that frustrating, and I've really devoted the last 11 to 12 years now to helping decrease blood loss on the battlefield. That was, in many respects, a life-changing experience that altered the track of my career, to go into the research environment, and to work on hemorrhage control and hemostasis and resuscitation issues."
The bandages were developed by HemCon, Inc., which develops and markets technologies to control severe bleeding for traumatic skin and organ injuries. The key ingredient in the shrimp shells is called chitosan. Kenton Gregory, a cardiologist from Providence St. Vincent Medical Center in Portland, Oregon who co-founded HemCon, says unlike the gauze that traditional bandages are made from, chitosan interacts with our blood cells because its molecules carry a positive charge.
"The problem with gauze is that it really has no clotting ability," Gregory explains. "Generally the gauze just saturates, is just saturated with blood, and the bleeding continues. The chitosan…has a positive charge. All of our cells, our red blood cells, the outer membranes have negative charges. And the negative charge of the red [blood] cell is attracted to the positive charge of the chitosan. As soon as they touch, the red cell fuses and forms a clot against the chitosan, and that forms a very tight, adherent clot, and a tight adherence to the surface of the wound."
The chitosan bandage.
After some impressive results in animal testing, the bandages were quickly approved by the Food and Drug Administration and immediately shipped to Iraq and Afghanistan. Gregory says besides increasing survival, the bandages also reduce blood loss in those who do survive. "That's very important from a tactical standpoint, because it will reduce the demand on very scarce transfusion products such as red blood cells or plasma," he says. "In a battlefield situation, those components are very, very scarce indeed, and obviously very, very expensive." Gregory and his team have also found that the bandages have an anti-bacterial quality, but that aspect/use has not yet been FDA-approved. Although currently the bandages are being made exclusively for the military, Gregory hopes they'll eventually be in every ambulance, hospital and household in the country.
Results From the Battlefield
Army officials say thousands of soldiers in Vietnam might have been saved if these chitosan bandages had been around. "When you look at the wound data from Vietnam, about 10 percent of all the fatal wounds were from uncontrolled hemorrhage or uncontrolled bleeding," says lieutenant colonel Ian Wedmore, a surgeon at the Madigan Army Medical Center in Tacoma, Washington. "So if you look at that and say, well if we have a device that would stop this uncontrolled hemorrhage, then you're saying that conceivably you could have saved up to 10 percent of those fatalities. So you're talking about 5,000 people."
Ian Wedmore in Iraq. image: U.S. Army
Wedmore collected some 40 anecdotal reports from medics who used the bandages on today's battlefields of Iraq, and he believes the bandages are saving lives. Following is one of the entries from his field survey: "RPG casualty with multiple frag wounds to groin. Profoundly hypotensive patient. As he was resuscitated developed diffuse groin oozing not controlled with kerlex and pressure alone. chitosan applied which controlled ooze and stabilized patient enough for transport to definitive surgical care. Without chitosan MD felt patient would not have survived to transport."
Reports like this are especially pleasing to Holcomb: "We're putting products on the battlefield now that are decreasing blood loss, and I think that's a real success story for the Department of Defense research community.... They are superior to gauze dressings, no question about it. Soldiers in the field are happy with it. The only problem is that they want more of them."