Saturday, July 05, 2008

Waging war on death


His armoured vehicle had been sent flying "like a Tonka toy" after striking a roadside bomb packed with three antitank mines. Now the young NATO soldier was bleeding to death and it seemed there was nothing Colonel Ron Brisebois and his colleagues at a Canadian-run military hospital near Kandahar could do to stop it.

Finally, the doctor from University of Alberta Hospital attempted a procedure that defied the time-worn conventions of trauma care and its cautious use of blood products and instead pumped in fresh, undiluted blood donated by other troops. Almost immediately, the potentially lethal hemorrhaging stopped.

Dr. Brisebois is among numerous military surgeons operating in Afghanistan and Iraq who have been experimenting with aggressive use of blood transfusions -- instead of the usual practice of first filling patients with salty fluid-- to stop massive bleeding. It is just one of the innovations developed in chaotic battlefield hospitals over the past few years that some physicians believe will eventually change emergency medicine, creating a peacetime dividend out of the carnage and heartache of war.

Battlefield practices that could come to influence civilian medicine include the revival of tourniquets to squeeze off bleeding, remarkable new first-aid powders that staunch gaping wounds in the field, a controversial new drug to encourage clotting and a growing understanding that post-traumatic stress disorder may often be caused by brain injury, not psychological stress.

"In many ways the EMS and emergency-medicine system that exists in the United States and Canada and most of the developed world today came from experiences in World War II, Korea [and] Vietnam," said Dr. Ron Stewart, a University of Texas surgeon who helps run the National Trauma Institute.

"In this current war, I personally believe those same things are happening."

In the past, carts that carried injured French soldiers in the Napoleonic campaigns led to ambulance use on city streets; triage centres created for casualties in the Second World War translated into the first hospital emergency rooms; and the helicopters used to airlift wounded troops in the Korean and Vietnam conflicts gave rise to the choppers that service most civilian trauma centres today.

News of those innovations, though, trickled out slowly and did not find their way into civilian practice until long after the fighting ended. Now military doctors are comparing notes constantly and many work closely with civilian colleagues between tours in the combat zones, noted Dr. Stewart: "This has been much more real time."

Canadian physicians are among those contributing to the Joint Theater Trauma Registry, a U. S.-run database on combat-injury cases in Iraq and Afghanistan expected to yield a gold mine of emergency-medicine knowledge. The registry contains descriptions of hundreds of injuries and exactly how they were treated, showing what works best.

Dr. Brisebois' patient, who had suffered a devastating pelvic fracture, arrived at the base hospital with no palpable pulse, and death seemed inevitable. Doctors pumped in 36 units of red blood cells, 38 units of fresh-frozen plasma and 70 units of platelets, all designed to bring about coagulation and, in this case, all ineffective.

Then, physicians transfused him with just five units of fresh whole blood donated by other troops at Kandahar Air Field, and the crisis was over. The practice is virtually unheard of -- and generally frowned upon -- in civilian hospitals, partly because blood taken from donors is always divided up into different types of products, like plasma and red blood cells.

But, Col. Brisebois said in a recent interview from Afghanistan, "it seems to work exceedingly well. We have essentially relearned the value of whole-blood transfusions in people with massive bleeding ... It does seem to be life-saving in some cases."

Actual whole blood itself will likely never make a comeback in civilian hospitals, because it must be transfused almost immediately after it is donated. But military surgeons are also aggressively transfusing separate blood products that together act like "reconstituted" whole blood, often achieving a similar effect. It is among the concepts that could soon be employed on car-crash survivors, shooting victims and other emergency-ward patients across Canada.

"It's important to be able to translate those lessons from the battlefield to civilian care, because it does save lives back home, too," said Dr. Stewart of the National Trauma Institute.

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BLOOD TRANSFUSIONS

Perhaps the most important advance emerging from field hospitals in Iraq and Afghanistan addresses the biggest killer among wounded soldiers: heavy bleeding.

The conventional approach to hemorrhaging trauma patients is to fill them with fluid: pump in saline solution intravenously, boosting blood volume and raising blood pressure, so the blood can do a better job of carrying oxygen to the body's cells. Blood products are then added in gradually, explains Major Homer Tien, an army trauma surgeon based in Toronto who has done three tours in Kandahar. The idea, in part, is to restrict use of transfused blood, a limited resource that can cause immune responses in some patients or potentially infect them with harmful diseases.

But surgeons in Iraq and Afghanistan began rethinking the approach as they faced more and more soldiers, usually wounded by roadside bombs and the like, suffering from "coagulopathy": hemorrhaging so intense it robs the body of its clotting ability, leading to more bleeding in an often fatal cycle. Combat doctors began employing the immediate and high-volume transfusion of blood products, or even whole blood, aimed at clotting the blood fast draining out of their patients.

"We need to rethink the ratio of blood and saline that we're transfusing," Maj. Tien said. "Maybe we should be giving blood up front, and we should be giving other forms of blood products upfront."

Not everyone, though, is convinced by the new concept, called damage-control resuscitation.

Studies have not shown clearly that it does, in fact, stop coagulopathy, said Dr. Gene Moore, chief of surgery at Colorado's Denver Health.

Civilian physicians should use caution before transfusing blood "pre-emptively" into trauma victims, because blood products are a precious commodity that can cause adverse reactions in rare cases, he said.

"We in civilian trauma centres shouldn't adopt these ideas without scientifically demonstrable results," Dr. Moore said.

STOPPING BLEEDING

The mayhem of Iraq and Afghanistan has heralded a comeback for the tourniquet, a piece of cloth or other material that is tied tightly around a limb just above a wound to stop bleeding.

First-aid protocol has for years dismissed tourniquets on the grounds that they can cut off circulation to the rest of the limb, which leads to tissue damage and even amputation.

Dr. Ray Wiss, an emergency doctor in Sudbury who recently spent three months in Afghanistan, had always counselled police tactical-team officers in his city against using the tools.

"It is axiomatic in my profession that you never use tourniquets," he said.

But military doctors say the simple devices --aided by new designs that make them easier to apply --have saved numerous lives of heavily bleeding patients in war zones.

They also say tourniquet-impeded circulation has not led to the loss of limbs, perhaps because patients are transported relatively promptly to field hospitals where the ligatures are removed.

Now Dr. Wiss, a captain in the army reserves, issues tourniquets to those same officers back in Sudbury.

In addition, there are new products applied directly to the injury to counter the often deadly bleeding suffered by badly wounded soldiers. The first was QuikClot, a powdered mixture of inert minerals poured into the site of bleeding, which essentially absorbs the blood and encourages clotting.

QuikClot is already available in Canada and deployed by paramedics who form part of police tactical teams, said Maj. Tien, the army trauma surgeon based in Toronto.

Like tourniquets, such products could help

civilians hurt in out-of-the-way locations or in hostage situations, and some civilian doctors have actually used QuikClot to quench bleeding from the livers of trauma patients, said Maj. Tien, who is a surgeon at Toronto's Sunnybrook Health Sciences Centre.

PTSD OR BRAIN INJURY?

Witnessing the sort of carnage military doctors try to patch up in Iraq and Afghanistan is one trigger for what is now recognized as a common fallout of war: post-traumatic stress disorder (PTSD). The National Defence Department recently revealed that as many as 1,500 Canadian veterans of service in Afghanistan suffered from PTSD -- typified by flashbacks, emotional numbness and depression-- or other psychological problems.

But the military is now carrying out research into whether the symptoms of PTSD might often be a result of physical injury: a bomb blast, for instance, that momentarily renders a soldier unconscious, said Maj. Tien.

"They may be knocked down. They might say, 'Oh, I had my clock rung.' But then they're awake, there's no penetration, no shrapnel and they feel good to go. The question is: 'What do you do with them?' "

If the theory that such relatively minor brain injuries leave soldiers with lasting mental symptoms is borne out, it could cast a whole new light on the many civilians whose heads take a beating in car accidents.

The armed forces are monitoring soldiers who have suffered such injuries to track the symptoms they develop down the road, he said.

Such research fits with civilian research into links between depression and concussions in athletes and others. A study published this year by the Montreal Neurological Institute used functional-MRI scans to show that concussions seem to cause physical changes in areas of the brain connected to depression. Researcher Dr. Michael Ptito said at the time he would like to study soldiers returning from Afghanistan: "They have all this body armour and reinforced vehicles, but warfare has changed and they have these improvised explosive devices and it's like the soldiers are in this tin can and their brains are shaken, but nothing is apparent. Then they have all these symptoms and they can't explain them."

CLOTTING METHODS

The unlicensed use of a new clotting drug on combat casualties --including badly wounded Canadian soldiers -- has sparked vigorous debate among military and civilian surgeons.

Known as recombinant Factor VIIa, the medication is approved in Canada and the United States for use on hemophiliacs. U. S. regulators have warned it could cause blood clots leading to strokes or heart attacks in patients not suffering from such blood disorders.

U. S. and other NATO military surgeons have been using it "off-label" to try to stop bleeding in patients suffering multiple penetrating wounds from roadside bombs, and they say it often works when all other treatments fail.

But critics are advising caution before it is adapted for regular medical use. "We are still very concerned about the translation of this usage into civilian practice," said Dr. Jawed Fareed, a pharmacologist at Chicago's Loyola University.

Surgeons working in the Canadian-run field hospital in Kandahar have been using Factor VIIa, albeit more sparingly than U. S. colleagues: perhaps six to eight times a year in smaller doses, said Col. Brisebois, who just returned from Afghanistan.

It is usually employed as a last resort when "we are a little desperate about how we're going to stop the bleeding," Maj. Tien said.

He used it on a 23-year-old Afghan National Army soldier who had taken a bullet through the chest and was coughing up "massive" amounts of blood--about 100 cc every 15 minutes, according to a paper in the Annals of Thoracic Surgery.

Standard procedures seemed incapable of stopping bleeding from the left lung. Finally, surgeons administered Factor VIIa and "within one minute" the soldier virtually stopped coughing up blood and began breathing more normally. He went home two weeks later.

Factor VIIa mimics a protein that is key to the body's coagulation system.

National Post

Cool picture

1 Comments:

Anonymous Anonymous said...

Interesting about tourniquets, here in the UK some clumsy fool at a NHS (don't get me wrong, an NHS is much better than no NHS but my oh my does it have it's faults) hosptial once who, as NHS staff often do, don't believe you when you tell them how serious an injury is. She then proceeded to scrub it violently, destroying the clot I had made by torching it with a lighter and arterial blood started flying across the room at which point she squeaked than quickly ran off and came back with... a tourniquet. This was about 7 years ago.

So, tourniquets don't seem out out favour everywhere.

11:36 PM  

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