Back from the dead


27th Mar 2018 Wellbeing

Back from the dead
How the strange new science of “suspended animation” will save lives
One afternoon in February 2011, American Kelly Dwyer strapped on snowshoes and set out to hike a beaver pond trail near her home in Hooksett, New Hampshire. Hours later, the 46-year-old teacher hadn’t returned home. Her husband, David, was worried. Grabbing his phone and a torch, he told their two daughters he was going to look for Mum. As he made his way towards the pond, he called out for Kelly. That’s when he heard the moans.
Running towards them, David phoned Laura, 14, and told her to call 911. His torch beam soon settled on Kelly, submerged up to her chest in a hole in the ice. As David clutched her from behind to keep her head above water, Kelly slumped into unconsciousness. By the time rescue crews arrived, her body temperature was in the 20s°C. Before she could reach the ambulance, her heart stopped. The crews attempted CPR—a process doctors continued for three hours at a hospital nearby. They warmed her frigid body. 
"Improvements in technology mean that the odds of coming back from death are getting better"
Nothing. Even defibrillation wouldn’t restart her heart. David assumed he’d lost her for good.
After falling through the ice while snowshoeing, Kelly Dwyer was “medically” dead for five hours before doctors got her heart beating again
But Kelly’s life wasn’t over. A doctor rushed her to the nearby Catholic Medical Center, where a new team hooked her up to a cardiac bypass machine that more aggressively warmed, filtered and oxygenated her blood, and rapidly circulated it through her body. Finally Kelly’s temperature crept back up. After she’d spent five hours medically dead, doctors turned off the machine and her heart began beating again.
Incredibly, Kelly Dwyer walked out of the hospital just two weeks later with only minor nerve damage to her hands.
Bringing people back from the “dead” isn’t science fiction any more. Typically, after just minutes without a heartbeat, brain cells start dying and an irreversible, lethal process is set in motion. But when a person becomes severely cold before their heart quits, their metabolism slows. The body sips so little oxygen that it can remain in a suspended state for hours without permanent cell damage.
Thanks to improvements in technology (like the cardiac bypass machine that saved Kelly’s life) the odds are getting better for coming back from the edge. They’re so good, in fact, that a handful of scientists and medical experts across the United States are now looking for ways to suspend life in order to perform surgeries without the threat of a trauma patient bleeding to death, or to prevent tissue damage during the treatment of cardiac events.
The US Department of Defence is also heavily involved. In 2010, it launched a $34m initiative called Biochronicity. Ninety per cent of war casualties result from bleeding out on the battlefield.
“We’re trying to decrease the person’s demand for blood so, for a period of time, they actually don’t need blood flowing,” explains Colonel Matthew Martin, a 49-year-old trauma surgeon whose research is funded through Biochronicity. The purpose would be making a wounded soldier able to survive longer “so that we can get somewhere to treat the injury,” says the active-duty surgeon.

Dr. Mark Roth’s office

at the Fred Hutchinson Cancer Research Center in Seattle is crammed with boxes of newspaper clippings about people who came back from the “dead.” There’s a skier in Norway, a toddler in Saskatchewan, two fishermen who capsized in the Gulf of Alaska—all of whom had flat-lined in the freezing cold.
“I’ve been a student of these cases for 20 years,” Dr. Roth tells me. At 60, he’s widely recognised as a pioneer in the pursuit of using suspended animation in trauma treatment.
Hunched over a microscope, he invited me to take a look at a petri dish bustling with tiny, hours-old zebra fish. “Because they’re transparent, you can see their hearts beating and the blood moving about the tail,” he says. “This is the core of our own animation—the heart and blood flow. We’re going to take away the oxygen and alter their animation.”
Dr. Roth began piping nitrogen into a transparent box containing the petri dish. “In time the whole system in there will become straight-up nitrogen, which will get to these creatures and turn them off,” he explains. “In the morning, we’ll put them back into the room air, and they’ll reanimate.”
Then he prepped a similar experiment. Taking two petri dishes of nematodes at precisely the same stage of development, he placed one dish in his nitrogen box and left the other on a lab bench. His hypothesis? The gassed worms’ metabolism should gradually slow until they’re essentially suspended in time, while the fresh-air siblings should keep getting bigger. Because nematodes grow quickly, his theory would be proved or disproved by tomorrow.
Up until the early 2000s, Dr. Roth’s experiments were confined to tiny creatures. Then one night he was watching a television documentary featuring a cave in Mexico that caused cavers to pass out because of an invisible hydrogen-sulfide gas.
“If you breathe too much of it, you collapse—you appear dead,” says Dr. Roth. “But if you’re brought out from the cave, you can be reanimated without harm. I thought, Wow! I have to get some of this!
After exposing mice to 80 parts per million of that gas at room temperature, he found he could induce a suspended state that could later be reversed by returning the mice to regular air, with no neurological harm. For Dr. Roth, it was a breakthrough. The medical community immediately took notice, seeing his work’s potential. A $500,000 “genius grant” from a philanthropic foundation followed soon after.
Since then Dr. Roth has identified four compounds (sulfur, bromine, iodine and selenium) that he now calls “elemental reducing agents,” or ERAs. These naturally exist in small amounts in humans and can slow a body’s oxygen use.
Dr. Roth wants to develop an ERA as an injectable drug that can, for one, prevent tissue damage that can occur after doctors halt a heart attack. This happens when normal blood flow resumes; the sudden rush of oxygen can permanently damage heart cells, leading to chronic heart disease (the leading cause of death in the world).
Roth’s current research in pigs shows that if he injects an ERA before the blockage is removed, it’s possible to keep the heart muscle from being destroyed. Human trials on heart-attack patients are already underway, and Dr. Roth says ERAs could one day be used for a range of medical conditions, including organ and limb transplants.

Dr. Sam Tisherman

hates the phrase “suspended animation.” As director of the Center for Critical Care and Trauma Education at University of Maryland’s School of Medicine in Baltimore, he prefers “emergency preservation and resuscitation (EPR).” “We want to preserve the person long enough to stop the bleeding and resuscitate him.”
Unlike Dr. Roth’s method, Dr. Tisherman’s approach is to cool patients into a hypothermic state. To do that, he replaces blood with extremely cold saline solution, quickly reducing the patient’s core temperature to a frigid ten to 12°C.
"Inducing a hypothermic state could buy surgeons as much as an hour"
Routine care for trauma victims with injuries such as gunshot wounds typically involves inserting a breathing tube, and then using intravenous catheters to replace fluids and blood while a surgeon attempts to repair the damage before the patient’s heart fails. “It’s a race against time,” Dr. Tisherman says, “and only five per cent of people in cardiac arrest from trauma survive.”
Inducing a hypothermic state could buy surgeons as much as an hour to operate. Dr. Tisherman and his colleagues have spent more than two decades perfecting their procedure in animals. In 2014, the US Food and Drug Administration gave them the go-ahead for the first human trials.
After four tours in Iraq and Afghanistan Col. Matthew Martin was trying to achieve the same results as Dr. Tisherman—without extensive equipment that would be impossible to bring to the front lines. That means using chemicals—not cold—to slow the body’s clock.
“The goal is to create ‘hip-pocket therapy’, ” he says, “where a medic could whip out a syringe for a severely injured soldier, inject it and start the process of suspended animation, giving the soldier more time to get to a surgical facility.”
He and his colleagues have identified a series of enzymes known as PI 3-kinase, which helps regulate metabolism. They also found a drug that controls the activity of those enzymes and is already in clinical trials as a potential cancer treatment. After examining the effects of the drug on pigs, Martin’s early data suggests that administering it at the moment of ischemia—when blood flow to the heart becomes inadequate—can slow down the metabolism without the risk of harming the animal.

Meanwhile, back In Seattle,

Dr. Roth is also hoping the answer lies within an injectable drug.
A day after putting his nematodes to sleep, the worms that spent the night in the nitrogen chamber hadn’t grown but were easily brought back to life when exposed to fresh air. The ones left out on the table had grown noticeably larger. Soon they would have babies of their own.
It’s a far cry from saving a human trauma patient. But witnessing those tiny worms “resurrected,” I felt I’d just seen a glimpse of the future.