Expanding injection foam is typically something you'd get if you were insulating your house or repairing a cracked foundation. However, according to a Defense Advanced Research Projects Agency (DARPA) report, we may start to see it used to treat wounded soldiers.
Abdominal wounds are especially deadly due to internal bleeding. Bleeding from other types of wounds can usually be stopped or at least significantly slowed simply by applying pressure to the wound. With abdominal wounds, the flow of blood might be stopped by applying pressure to the entry wound (and exit wound, if there is one), however there is going to be internal bleeding from damaged organs that will still kill the soldier if they aren't dealt with quickly. DARPA's Wound Stasis program began back in 2010, looking for a way to prevent deaths due to abdominal wounds and internal bleeding.
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The 'Arsenal Foam System', developed by Arsenal Medical in collaboration with DARPA, is a two-part liquid that is injected into an abdominal wound. When the liquids combine, they quickly expand to 30 times their initial volume and form a solid foam. According to the DARPA news release, "The foam can expand through pooled and clotted blood and despite the significant hydrostatic force of an active hemorrhage," (meaning that even though blood exiting out of a torn artery or vein will exert pressure against the foam, the foam can still expand to make contact with the artery or vein and thus stop the bleeding).
Testing of the foam on pigs showed an over 80 per cent reduction in bleeding of treated wounds, and a survival rate of 72 per cent (compared to eight per cent in the control group) even up to three hours after the injury was sustained. It took doctors less than a minute to remove the foam, through a minor surgical incision, as one solid block. Examination of the foam showed that there was only minimal absorption of blood, and only at the surface that directly contacted the wound, proving that it effectively stopped the bleeding.
This kind of development also has applications beyond the military.
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First responders could use this for shooting victims (of course), but also those with internal bleeding from injuries suffered in car accidents and in the workplace, and with the time frames seen in testing, this would be especially useful for emergencies in remote areas. Doctors could also use it more routinely, during surgery to control bleeding while they work.
The researchers presented their findings at the 2012 Annual Meeting of the American Association for the Surgery of Trauma in Kauai, Hawaii, and should be working with the Federal Drug Administration (FDA) in clinical development of the product very soon.