— Polyurethane foam, long used in products such as bedding,
furniture and insulation to make people more comfortable,
someday also may save lives.
Johns Hopkins University biomedical engineering students have
devised a tool that may stop profuse bleeding by injecting the
foam into those wounded on the battlefield.
class project, the students chose to tackle the problem of
hemorrhaging, the top cause of death for service members in
war. Existing devices — tourniquets and medicated bandages
— can be unusable or ineffective in wounds to the neck or
where limbs meet the torso.
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,
the student team leader and a recent Hopkins graduate.
could stop the bleeding long enough to get the patient to a
surgeon, Rooney said.
technique is far from being approved by the government for
use, but military and Hopkins trauma physicians say the idea
is about the size of a whiteboard marker and holds two liquid
chemicals that make foam when mixed. Ideally, when the foam is
plunged into a wound, it quickly hardens and stops the
designed to be stable up to a temperature of 100 degrees,
portable and simple to use. If it didn’t have those
qualities, "our target audience wouldn’t use it,"
said Rooney, a 21-year-old who just began medical school at
Vanderbilt School of Medicine in Nashville, Tenn.
the past year and a half, the students experimented with gel
to mimic human tissue and rods filled with water to take the
place of blood vessels. They damaged the rods and injected the
foam to stop the fluid loss. It hardened and applied pressure
to the cavity walls, as planned.
Walter Franz, an Army Reserve colonel who has led
"forward surgical teams" in Iraq and Afghanistan,
said medical providers have developed the best methods to save
lives on the battlefield over time.
a medic provides what lifesaving care he can on the
battlefield, applying gauze and tourniquets to heavily
bleeding wounds. Then the doctors and nurses of the forward
surgical team patch the wounds, often in a tent close to the
war zone, ahead of full-scale surgical fixes in a trauma
hospital farther away.
an urgent need for new tools for the medics, said Franz, a
family physician at the Mayo Clinic in Minnesota and former
commander of the Army Medical Corps 945th Forward Surgical
works to bring best practices from the battlefield to
front-line trauma teams in the United States. Franz said the
emergency medical technicians who work out of ambulances and
helicopters usually are closer to trauma hospitals but also
could benefit from such a tool.
is some bleeding we can’t see and can’t get a tourniquet
around it," he said. "We need a product we can pull
out of a bag, which is self-contained and simple. … I’d
say to the Hopkins students, ‘Keep working on it.’"
he and other doctors had questions about the foam. How easy
would it be for a nonsurgeon to place the foam in the right
place, avoiding organs and healthy vessels? How easy would it
be for doctors to remove the foam during surgery? Could it
generate heat or have a chemical reaction inside the body?
Would it irritate bodily tissue? Could it be toxic if left in
too long? Is it stable at 30,000 feet in a helicopter used for
transport over mountains in cold air?
may be high hurdles to overcome, said Dr. Jeffrey A. Bailey,
an Air Force colonel and trauma surgeon who works in the
military health system in San Antonio, Tex., as the joint
trauma system director. The system makes recommendations on
using new devices.
the foam tool would need U.S. Food and Drug Administration
approval. Then the military would need to evaluate its
effectiveness on the battlefield, develop guidelines and
training. Even then, officials would need to constantly
evaluate its effectiveness.
need to do this in a ditch or a Humvee. It’s a whole
different world on the battlefield," he said. "But
it offers some hope and real potential."
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many of the students have graduated from Hopkins or moved on
to other classes, the continued development and testing of the
device falls to doctors who sponsored the class project at All
Children’s Hospital in St. Petersburg, Fla., part of the
Johns Hopkins Medicine system and a training site for medics
in the Green Berets, Navy SEALS, Army Rangers and Marine
includes Dr. Paul D. Danielson, a colonel in the Army Reserve
and a pediatric trauma surgeon at All Children’s. Danielson
also served in a forward surgical team in Iraq and
he’s been frustrated by difficulty of controlling bleeding,
which has often killed wounded service members before they
reached help. Attempts to stop bleeding from junctional wounds
using balloons and beads have failed. One clotting agent
called Factor VII had mixed long-term results and was
students did some testing on the foam to rule out problems
associated with temperature, user skills and biocompatibility.
Now the doctors are focusing on making sure there is
sufficient foam to clog a wound and that it hardens within 10
seconds. Doctors brought in a chemical engineer to work on the
balance is achieved, Danielson said, the doctors will find a
manufacturer to make the plastic device. Eventually, to ensure
safety and efficacy, they will begin testing on live tissue,
animal and then human, perhaps in an emergency or operating
said he figures it will take about a year to know if the
device is viable.
these problems are much better problems to have than how to
notify the next of kin when someone dies," he said.
"We can’t put a surgeon on the battlefield to treat the
wounded. We need to keep them alive long enough to get to