Hypothermal Intention

London: Researchers are testing potentially life-saving techniques for keeping humans in a state of suspended animation while surgeons repair their wounds.

US doctors have developed a method of inducing hypothermia to shut down the body’s functions for up to three hours.

In tests, they reduced the body temperature of injured pigs from 37C to 10C before operating on them and then reviving them.

Now they are applying for permission to test the procedure on casualty patients without a pulse who have lost large amounts of blood, New Scientist magazine reported.

It is thought this method and others could one day be used on car crash and gunshot victims, as well as in the battlefield to treat wounded soldiers.

A surgeon at Massachusetts General Hospital in Boston, Hasan Alam, has tested the technique about 200 times on pigs, with a 90 per cent success rate.

First he anaesthetises the animal, then cuts a major vein and artery in its abdomen to simulate multiple gunshots to a person’s chest and abdomen.
As the pig rapidly loses about half its blood and enters a state of shock, Dr Alam drains its blood and stores it before pumping chilled organ preservation fluid into its system.

The animal’s body temperature falls to about 10C until it is in a state of “profound hypothermia” and has no pulse and no electrical activity in its brain.

But after the blood stored earlier is warmed and pumped back into the pig’s body its heart starts beating again and it comes back to life.

“It is still pretty awe-inspiring,” Dr Alam said. “Once the heart starts beating and the blood starts pumping, voila, you’ve got another animal that’s come back from the other side.

“Technically, I think we can do it in humans.”

He now wants automatic consent to use the technique on all patients brought to his hospital who have lost blood and would probably die with only standard care.

Other US researchers are working on methods to place organisms in suspended animation by exposing them to a cocktail of gases, including hydrogen sulphide.

Press Association

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2006년 1월에 보도된 뉴스입니다. 2005년에 사파 연구소의 연구진이 죽은 개를 되살려낸 데 흥분해 관련 보도들이 쏟아지고 약간 후의 내용이죠. 매사추세츠 대학은 저체온요법 관련 기사를 검색하다보면 자주 등장하곤 합니다. 소생의학에 대한 이 대학의 권위 덕분일 겁니다.

아직 궁금한 것은 피를 빼내고 그 자리를 보존액으로 대체하는 과정이 어떻게 진행될까 하는 것입니다. 돼지 실험의 경우를 보면 정맥과 동맥을 각각 끊어놓던데, 피를 모두 빼낸 뒤 보존액을 넣는 것인지, 혈관을 끊어 한 쪽 절단면에서 피를 빼냄과 동시에 반대편 혈관으로 보존액을 넣는 것인지 잘 모르겠네요. 어떤 자료를 찾아보든지간에 이 부분은 ‘교환한다’, ‘체액을 빼내고 보존액을 넣는다’ 식으로 두루뭉수리하게 넘어갑니다. 갑갑하네요.

Tabloid headlines screamed ‘Night of the Living Dog’ when scientists said they had found a way to bring dead dogs back to life.

It was indeed an amazing story ” which explained the tabloids’ incredulity, and their interpretation of the discovery by scientists of the Safar Center for Resuscitation Research at the University of Pittsburgh, Pennsylvania. It was reported that a New York Post journalist asked the director of the resuscitation centre, Dr Peter Kochanek, if he was ‘creating a race of zombie dogs fit for a Stephen King novel’.The team at Safar ” which was founded by the late Peter Safar, who invented modern mouth-to-mouth resuscitation ” weren’t pleased at the frivolous coverage of their work.

The Safar scientists have developed a way to put the dogs into a hypothermia- like state ” also known as suspended animation ” which puts the animals’ metabolism on hold. The process involves draining the dogs’ veins of blood and then filling them with a near ice-cold salt solution, which lowers body temperature to 7C (usually 37C). They stop breathing and have no heartbeat or brain activity, so are considered clinically dead.

Three hours later, the dogs’ blood is replaced and they are brought back to life with a gentle electric shock. The Safar scientists have since announced that they hope to test their hypothermic cooling techniques on humans and have gone as far as talking to hospitals about starting trials on emergency patients.

The aim is to buy time for people who have suffered massive blood loss through injury. They hope that soldiers wounded in the battle or people injured in car accidents or shootings could be preserved long enough to move them to a hospital, repair the damage and revive them.

‘We hope to start trials [on humans] within a year,’ says Dr Samuel Tisherman, the associate director of the Safar Center. ‘We will probably focus on victims of penetrating trauma, such as gunshot or stab wounds, causing cardiac arrest. We’d try usual resuscitation attempts first and if we don’t get anywhere, try suspended animation.’

In using the hypothermic method, the human patient’s blood would be drained and they would be flushed with a cold saline solution leaving them hovering in limbo between life and death.

‘We’ve got a concept in emergency treatment called the ‘golden hour‘,’ says Dr Howard Champion, a British-born trauma surgeon based in the US. ‘This refers to the precious little time you have to get somebody who’s bleeding to death to a hospital. The whole idea behind suspended animation or hypothermic cooling therapy is to buy extra time.’

Injury is a major cause of death around the world, resulting in about eight million deaths a year. Forty to 50 per cent of these bleed to death. And 20 to 30 per cent of those, says Champion, bleed from injuries which, if treated in time, are fixable. ‘That’s the target we’re after with hypothermic cooling.’

One of the most obvious applications is on the battlefield, which is why US defence agencies have provided funding for the Safar Center. According to Champion, medics would be alerted to wounded soldiers by sensors. ‘The sensors would tell us when a soldier has received an impact of a given level of kinetic energy and may have injuries that could cause fatal bleeding. We would pick up the soldier and put him through the hypothermic process, giving him a much greater chance of survival.’

Even more futuristic sounding, the Pentagon recently awarded $12m (pounds 7m) in grants to develop an unmanned ‘trauma pod’ that would turn a drone (unmanned aerial vehicle) into an air ambulance. It would swoop down on an injured soldier, run X-rays and CT scans and even perform full scalpel- and-stitch surgery with robotic arms controlled by remote medics.

Such advanced vehicles are at least a decade away, so hypothermic cooling therapy is likely to be another of the technologies built into the trauma pod.

In the civilian world, the benefits of hypothermic cooling could be huge for people involved in accidents or violence. ‘It would have a big impact on the survival rates of people with traumatic injuries sustained from road accidents and gunshot or stab wounds,’ says Mark Voelker, a scientist at California-based BioTime Inc, another organisation experimenting with hypothermic cooling.

‘Now, when emergency crews find an injured person lying in the street with their heart stopped, there may be little they can do. But if hypothermic cooling apparatus were on hand in ambulances, they could put a patient’s metabolism on hold by cooling them down and then make attempts to stabilise them. The crew would then have a couple of hours to get the injured person to hospital.’

Voelker sees hypothermic cooling as a way to push back the boundaries of death. ‘The definition of death depends on the technology you have to revive the subject,’ he says. ‘As medical technology gets better, the limits to being dead are pushed into more extreme physiological states. Death is really when a doctor says: ‘I can’t do any more.”

In the Safar Center’s experiments, not all the dogs came out unscathed ” a few suffered serious physical and behavioural problems. Champion says this is to be expected: ‘You can never make a smooth transition from one environment to another. There will always be bugs to be ironed out.’

But some people believe issues arise from the fact of being clinically dead for long periods. They worry that, if the procedure is used on humans, they may wake up without souls.

Ross Heaven, author of Vodou Shaman, says: ‘What the scientists are doing has parallels with the zombie experience in Haiti, where voodoo priests administer tetrodotoxin [a powerful nerve poison derived from puffer fish] and plant mixtures. This slows the body and sends the subject into a semi-comatose state. They are then buried for a few days and dug up in a big show.

‘But they are not whole afterwards. According to voodoo practitioners, they’re in a zombie state because their souls are missing. So it wouldn’t come as a surprise to some that a few of these dogs displayed freaky behaviour after being clinically dead for three hours.

‘Maybe, if the same technique is used on humans, you could justifiably wonder whether they would come back to life with an essential part of them missing,’ Heaven says.

The Church of England doesn’t believe there is a risk to the soul. ‘From our point of view, there isn’t an issue about the person coming back to life or not,’ a Church press officer said. ‘Clearly, if you can be brought back to life you aren’t completely dead. We regard many new medical technologies as an extension of God’s care.’

Susan Blackmore, a writer and visiting lecturer to the University of the West of England, has studied near-death experiences. ‘I’d expect that if you got this procedure right by making sure the person received the correct level of nutrients and oxygen, then the person would come back just as they were before,’ she says.

She concedes that a patient could claim to have had a near-death experience, but says this wouldn’t prove anything. ‘Different parts of the brain respond in different ways when you come close to death because of their structure. Again, there is no need to invoke a soul. And I would guess that if people had this hypothermic procedure, some would have near-death experiences. But that would not show that a soul is leaving the body,’ Blackmore says.

Advocates of hypothermic cooling are understandably exasperated when spiritual issues arise. Champion insists: ‘This is not resurrection research.’

But the wider issues will not go away. In fact, they’ll run riot if the therapy is used on a human. When it is, as the BioTime scientist Mark Voelker points out: ‘We will be reading about the first ice-cold human.’ And you can bet we’ll hear a lot more about zombies, too.

Jimmy Lee Shreeve

Copyright 2005 Independent Newspapers UK Limited
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