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thedrifter
01-30-07, 08:31 AM
Doctors: Update manuals for today’s wounds, methods

By Kelly Kennedy - Staff writer
Posted : February 05, 2007

With the number of service members wounded in Iraq reaching 23,114 as of Jan. 25, members of the American Academy of Orthopaedic Surgeons have had plenty of opportunities to look at the way injuries are handled in the combat zone.

What they’ve found is that the unconventional warfare in Iraq shows that some conventional treatments for extremity war injuries may be outdated — and that the Defense Department may need to look at changing training and surgery manuals.

For example, surgeons argued that tourniquets should not be taught as a last resort that automatically leads to amputation, and that irrigating wounds to remove harmful bacteria could actually push the bad bugs further into the flesh.

At the annual Extremity War Injuries symposium in Washington, D.C., on Jan. 24-27, physicians and researchers met to talk about what works and how they can do things better. To that end, speakers also talked about applying for grant money and stressing the immediacy of their research.

“If it doesn’t have relevance or it doesn’t have an impact, who cares?” said Joseph Wenke, manager for the Army’s Orthopaedic Trauma Research Program at the Institute of Surgical Research. “We’re looking for proposals that will make a difference within five years.”

Surgeons have known since the Trojan Wars that combat wounds tend to be much more complex that those suffered in the civilian world. Conditions are dirtier, people often have to be treated as fighting continues around them, and it can take some time before they make it to a hospital.

In today’s wars, the wounded often have multiple injuries, as well as contamination caused when explosive high-velocity munitions push bacteria deep into the body. In Iraq, 70 percent of injuries are to service members’ extremities.

In 2006, Congress gave the academy $7.5 million through appropriations to create the Orthopaedic Trauma Research Program, which is using the money for grants relating to combat trauma — everything from using existing muscles to control prosthetic devices, to figuring out just how much flesh needs to be removed around a wound to prevent infection.

Some of the results have been surprising. Army Col. John Kragh Jr., an orthopedist at the Army Institute of Research at Fort Sam Houston, Texas, reported that using a tourniquet in combat results in amputation only 1 percent of the time. But people are often taught that they should use a tourniquet only as a last resort because it will result in an amputation.

Kragh argued that with proper monitoring and placement, that’s just not true.

And Navy Capt. Frank Butler, medical consultant to the Navy’s Medical Lessons Learned Center, said not using tourniquets has resulted in some deaths that were “potentially preventable.”

Army Col. Roman Hayda, acting chief of orthopedic services at Brooke Army Medical Center, gave a presentation about contamination and war wounds. He reported that recent studies show some irrigation methods — common practice for extremity wounds — may actually push infection further into a wound, and that more research needs to be done to find the best means to clean out a wound.

Ellie

thedrifter
01-30-07, 08:33 AM
Enzyme may limit damage in brain injuries

By Kelly Kennedy - Staff writer
Posted : February 05, 2007

Scientists know the brain damages itself further after a traumatic head injury by releasing a chemical that can kill many more brain cells — an issue hundreds of Marines and soldiers face in the wars in Iraq and Afghanistan.

But researchers haven’t been able to use drugs to contain the naturally occurring substance — called glutamate — because the drugs don’t eliminate it. After a drug leaves a person’s system, the glutamate remains, and it can continue to kill brain cells.

“Once [drugs] disappear from the brain, the excess glutamate is still there and will resume its neurotoxicity — so no long-lasting therapeutic effects can be achieved,” said Vivian Teichberg of the Weizmann Instititute of Science’s Neurobiology Department in Israel.

He and his colleagues have found a promising new approach. After years of trying to wrap their brains around the problem, the researchers think they’ve found a way to wrap the problem around the brain.

Normally, glutamate works as a neurotransmitter — a chemical that transmits signals across gaps between cells in the brain. Glutamate is believed to help with learning and memory. But it’s also a stimulator, and too much is like a kindergartner on cotton candy. So the body also has glutamate “transporters” — or pumps — that gather the chemical up into brain cells after it has done its job.

But after a head injury, the glutamate becomes toxic when it pools outside the injured brain cells and then overexcites neighboring healthy brain cells until they die.

Through research on rats, Teichberg said, a solution may have been found.

Rather than using a drug, researchers activate a blood enzyme that normally travels through the brain to mop up excess glutamate.

“We focus on the excess glutamate that floods the brain after an injury, and instead of trying to block its [harmful] actions, we pump it from the brain fluids into [the] blood,” Teichberg said.

Blood naturally has higher levels of glutamate than brain fluids do, and if blood glutamate levels become low, it kicks the glutamate pumps into high gear. So if scientists could lower glutamate levels in the blood, the pumps would quickly work to gather glutamate in the brain.

Teichberg and his associates used an enzyme called Glutamic-Oxaloacetic Transaminas, also a naturally occurring substance in blood. GOT can bind glutamate chemically to inactivate it. In the experiment, activating GOT lowered glutamate levels in the blood of rats with traumatic head injuries, which caused the pumps to pick up the excess glutamate in their brains and dispose of it in the blood.

Military health experts call traumatic brain injuries the “signature injury” of current wars. Advances in body armor are allowing many more troops to survive explosions that once would have killed them, but those explosions still wreak havoc on their brains.

When trying to treat people with brain injuries, including those suffering nerve-agent injuries, drugs often can’t make it past the blood-brain barrier — a series of cells that protects the brain from bad substances in the blood while letting nutrients flow through. The barrier tags many drugs as “harmful” and doesn’t let them through. But some nerve agents do get through, and then can’t be counteracted with drugs because of the barrier. Using GOT could also prove effective there.

Ellie