For the purposes of this experiment, though, pigs are just fine. Because today’s focus is not on CPR, but on cooling. Specifically, Josh is interested in how to cool a pig—or a person—as quickly as possible down to the temperatures that saved Bigelow’s mongrel dogs. But this isn’t as easy as it sounds.
It’s a matter of physics, Josh explains. You need to find a way to cool a substance—in this case, bacon—as fast as possible, and as evenly as possible. And that, he says, is all about maximizing the rate of energy transfer.
This is difficult because the body is designed to conserve heat and retain energy. Our brains and other vital organs are buried within an insulating shell of water, fat, and muscle (which is mostly water), making our bodies exceptionally good insulators. To an engineer like Josh, you are just a large, soft, ambulatory thermos.
Insulation is great if you’re trying to stay warm on a walk to the corner coffee shop on a cold January day. But it’s not so great if you’ve suffered a cardiac arrest and your future brain health—and your ability to pay for a latte with the correct change—depend on getting your brain as cold as possible, as fast as possible. Under those circumstances, you’d wish that your body were a little less insulated.
So efforts to cool victims of cardiac arrest are restricted by our bodies’ built-in resistance. This is one of the biggest challenges of improving survival rates. In two randomized controlled trials, for instance, independent groups used cold saline given intravenously to cool cardiac arrest victims. They found a 16 to 25 percent absolute increase in the likelihood of recovering with only minor disability. However, in the real world, outside of a carefully controlled trial, patients may not do as well. In one large study, a patient with an initial rhythm of ventricular tachycardia who gets cold saline would only have about a 50 percent chance of a good long-term outcome.
So if you have a cardiac arrest, you definitely want to get very cold, very quickly. But how? Surely there’s something more effective—and quicker—than cold saltwater?
Petunia is just one of a series of pigs that Josh hopes will answer this question. Essentially, Josh and his team are trying to determine how fast they can achieve a target temperature of 32 degrees Celsius. (That’s much warmer than Anna Bågenholm’s temperature of 13.7, but remember that she was immersed in ice-cold water for more than an hour. And, of course, Josh’s work is just a first step.) Actually, the experiments are much more complicated than that, and involve precise measurements of temperatures throughout the brain and body, as well as measurements of blood flow and metabolism. But Josh is wisely giving me the CliffsNotes version.
In these experiments, he’s trying several methods, including intravenous cold saline (the current standard of care), a nasal device, and an intravenous cooling solution. In today’s session, he’s also testing a fourth option. It’s a cooling catheter inserted into the femoral vein in the inside of the hind leg and up into the inferior vena cava that runs through the abdomen, where it chills the blood that flows past. Josh and his crew will try these methods on an animal without any circulation, as well as on pigs that are anesthetized, and on those like Petunia who are receiving CPR. All of these variations notwithstanding, the goal of each of these experiments is pretty simple: to see how fast each method cools a pig.
Tracing all of these tubes and wires back and forth from Petunia to the monitoring equipment around her, I’m struck by the vast array of temperature sensors being used. Josh is monitoring temperatures in the brain, in the abdomen, and at the tympanic membrane in the ear, among other places. So which temperature is most important? What cooling rate does he look at most closely?
“Ideally,” he says, “we’d cool the brain first, then the heart. So those are some of the most important measurements.”
But is that possible? Could you design a cooling mechanism that would target the brain?
“Yes, in theory,” Josh admits. “You can use a catheter in a carotid artery, which would let you chill the brain quickly. But overcooling is a significant risk.” That is, if you bypass the body’s insulating properties and feed ice-cold saline to the brain, you could lower its temperature too far, too fast.
I mention that some researchers are trying to do exactly this. As we speak, researchers at the Safar Center are starting a trial that will push the limits of cooling. They’ll be trying to chill victims of severe trauma down to 10 degrees Celsius, even colder than Anna Bågenholm was.
Josh nods and gets a dreamy, far-off look. He already knows about that trial, of course. I can’t see the portion of his face that’s hidden behind the surgical mask, but I think he’s smiling. He knows how many lives (and brains) could be saved by advances like that.
Indeed, there are some amazing innovations that have enormous potential. And Josh, an engineer who has devoted his career to trying to save lives, and brains, appreciates them as much as anyone.
Josh’s research is part of a race, of sorts. Research is expensive, and the costs of failed experiments are high. But the potential benefits—medical and financial—are enormous. So as with any business that is driven by venture capital and industry, everyone has a dog—or a pig—in that race. And where there is a lot of innovation (and money) there are product names crafted by teams of executives hungry for market share.
The winner in the naming category, at least on my scorecard, is the RhinoChill. This is one of the methods that Josh is testing and whose name at first might seem better suited to the energy drink market than to resuscitation technology. The RhinoChill is a device that is inserted into a victim’s nose (hence the prefix “rhino”). It uses liquid perfluorocarbon (or PFC), forced out by high-flow oxygen, to cool the thin skeletal structure known as the cribriform plate that separates your nasal passages from your brain. The liquid PFC is at room temperature, but it evaporates at 0 degrees Celsius. This evaporation pulls heat from the dense network of vessels in the cribriform plate, cooling the blood as it flows through.
Think about the way a dog pants to cool off, using the blood vessels in its tongue to shed excess heat. The RhinoChill is basically a way to get your brain to pant, without the messy slobber on the kitchen floor.
RhinoChill’s grammatically unfortunate motto is “Saving Brain. Saving Life,” which makes it sound like Tarzan took over their marketing department. Initial reports are promising, though, Josh tells me. Perhaps soon they’ll be able to afford a new copywriter.
As the experiment wraps up, Josh tells me more about this and other novel ways of cooling people. Petunia is offering the final bits of data that, one hopes, will guide decisions about which method of cooling works best. As she does, Josh begins to wax philosophical about what he’s doing, and why.
“A lot of what we’re doing seems crazy,” he admits.
It’s less a statement than a question. But I shake my head. It doesn’t seem crazy to me at all. In fact, it’s not difficult to imagine a world in which cooling—rather than CPR—is the first order of business. It seems entirely plausible that cooling could offer more benefit than CPR does.
That was what happened to Anna Bågenholm. At least initially, her body temperature dropped by more than 20 degrees Celsius. But she didn’t get CPR until more than an hour later. As Josh’s work illustrates, the technical challenges of cooling a person—or even a pig—are considerable. In the end, though, they are just technical challenges, which Josh is convinced we’ll solve.
As we’re talking, Petunia’s mechanical rescuer finally stops. The room is eerily quiet, except for a few frantic beeps from monitoring equipment that have sensed—correctly—that the end is near. Soon those alarms, too, are silenced and the room is still.
4
Science Fiction, Space Travel, and Suspended Animation
THE HUMAN BEAR
If you believe even half of his story, Mitsutaka Uchikoshi is a very, very lucky man. He is also, some would say, not a very bright man. But fortunately t
hose two attributes—luck and lack of common sense—often seem to cancel each other out. At least when we’re talking about strange stories of survival.
On October 7, 2006, the thirty-five-year-old Uchikoshi attended a company picnic in a park on Mount Rokko, an oasis in the industrialized Hanshin region of Japan. From downtown Kobe, the park is a ten-minute cable-car ride, which is how Uchikoshi got there with his coworkers. But after a long day of partying, rather than return home the same way, Uchikoshi decided to find his way down the mountain on foot. That probably wasn’t his finest decision.
Stumbling down the slope, he became confused and lost his way. He tried to cross a stream, but he slipped and fell, sustaining a pelvic fracture that left him unable to walk. This made his situation particularly dire, because even under the best of circumstances a pelvic fracture can lead to pneumonia, bloodstream infections, and death. And lying on the side of a mountain as night is approaching is hardly the best of circumstances.
So Uchikoshi lay there, exposed to the cold and rain, hoping that some of his friends would miss him and start searching. Soon. But they didn’t. Some friends, right?
The night passed, and then the following day. And then another night. Uchikoshi’s death was starting to seem inevitable.
Except that it wasn’t. Twenty-four days later, a passing climber found him, barely alive. The barely alive part, by itself, is remarkable, given his injuries, exposure, and lack of food or water.
What was truly unusual, though, and what inspired a global media frenzy, was the fact that when he was discovered Uchikoshi’s temperature was only 22 degrees Celsius. Temperatures in that range have been recorded for drowning victims pulled from ice-cold water without a pulse, so that’s not remarkable. But Uchikoshi was unquestionably alive. His heart was beating, and he was breathing.
That makes his story very different from those of Michelle Funk or Anna Bågenholm. They were dead. They had no heartbeat, and they weren’t breathing. Uchikoshi did have a heartbeat, and he was breathing. Yet his temperature wasn’t compatible with life.
So he wasn’t dead. He was . . . well, no one was quite sure how to describe him. It seemed as though he was in a state of suspended animation.
There’s one problem, though. Suspended animation is not possible. Outside of science fiction, people just don’t enter a state of suspended animation. Yet Uchikoshi seemed to be doing a pretty good impersonation of someone who had.
Uchikoshi was transferred to the Kobe City Medical Center General Hospital, where he was in critical condition with internal bleeding and a pelvic fracture. But he pulled through, and soon he was talking with the press. Uchikoshi didn’t just survive, he also recovered. Doctors were confident about his chances for a full return to normal. For instance, Dr. Shinichi Sato, head of the hospital’s emergency unit, said that he believed Uchikoshi’s cognitive ability had recovered “one hundred percent.”
At the time, there were at least a few researchers who believed that Uchikoshi had managed to achieve a state of suspended animation. They then proceeded to give themselves rotator cuff tears reaching for hyperboles. Uchikoshi’s case was “revolutionary,” they said. It was “utterly extraordinary.”
Was this really an instance of suspended animation? Well, maybe. But we’ll never know how many of those twenty-four days Uchikoshi spent in the state in which his rescuers found him. Maybe he’d had a more or less normal temperature for the previous twenty-three days and then, on that final day, he became hypothermic on his way to becoming dead. And maybe that climber found him just before he died.
What is inarguably extraordinary about Uchikoshi’s story, though, is the way that it sparked the public’s imagination. The media didn’t hesitate to point out in headlines that Uchikoshi’s survival opened up the possibility of using suspended animation to stabilize patients who were critically ill. “First known human case may help future treatment,” was a common theme. These reports didn’t just trumpet a miracle, they also promised an entirely new therapy that could buy time for patients who otherwise had no time left.
But could people really benefit from the luck that saved a directionally challenged office worker? Could suspended animation, under controlled conditions, stabilize and protect a patient who is critically ill? And for how long?
SPACE TRAVEL AND LEMON-SCENTED NAPKINS
If you want to think about these questions, and especially if you’re a scientist who wants to think about these questions, you’ll face one enormous challenge. It’s quite difficult to deal with the science of suspended animation without confronting its numerous wacky appearances in science fiction. In dozens of films, suspended animation is used—and dare I say overused—as a plot device.
It’s employed to achieve a neat ending as a troublesome character is put into storage (A.I. Artificial Intelligence), for instance, and as a convenient setup for the removal of annoying or extraneous characters (2001: A Space Odyssey). But its most pervasive use is arguably as an adjuvant to space travel. It seems that you have to be in a state of suspended animation to get anywhere (Event Horizon, Alien, Planet of the Apes, Avatar, Pandorum, Outland . . .). Indeed, this mode of travel is almost inescapable unless you’re only going as far as the moon, and sometimes even then (see, for example, Moon). Thanks to hundreds of screenwriters over the past fifty years, suspended animation has become the dominant way to bypass the vagaries of economy class space travel.
At least that’s a reasonable use for it, and one with which most of us can identify. Think about it the next time you find yourself on a long-haul flight, crammed into an economy class piece of real estate that is barely large enough to provide breathing room for a midsize Chihuahua and her chew toy, next to a screaming child whose parents are eight rows back. How many frequent flier miles would you pay for nine or more hours of suspended animation?
But the real science of suspended animation has taken quite a beating as a result of the humorous uses to which it’s been put in film. There is, for instance, Miles Monroe in Sleeper, who wakes up after two hundred years, wrapped in tinfoil like last week’s corned beef on rye. And there’s the French comedy Hibernatus, in which the protagonist wakes up after sixty-five years in a small town that has been created in the image of 1905 to avoid the shock that would no doubt ensue were the character to realize what has happened. (The same trope, incidentally, appears in Captain America.) And there is my own personal favorite, Douglas Adams’s Hitchhiker’s Guide to the Galaxy series, in which a spaceship’s crew puts the entire passenger manifest in suspended animation because they can’t bear the thought of taking off without an adequate supply of lemon-scented napkins.
If you’re a serious scientist who studies suspended animation, and if you’re trying to explain your research to a perfect stranger, the sad truth is that any mention of your work is likely to be met by goofy grins, snide comments, and snarky press coverage. What it is very unlikely to be met with, though, is serious attention, a legitimate scientific reputation, or research funding.
But if suspended animation means slowing a person’s metabolism to the point that all of the normal processes of life are put on hold, then similar processes occur in nature all the time. Hibernating animals, like rodents and bears, can achieve a similar state by slowing their breathing (often down to one breath per minute) and heart rate (a couple of beats per minute). A hibernating animal’s temperature drops too, often down to just a little above freezing. And the most important feature of hibernation is that the animal’s metabolism slows, reducing oxygen consumption to as little as 5 percent of normal.
Reptiles experience a similar process when they “brumate.” Since they’re cold-blooded, reptiles can’t control their own temperature. Therefore, technically speaking, they can’t hibernate. But when they brumate, they simply choose an environment in which their body temperature will fall. The net effect of slowed heart rate, breathing, and metabolism is very similar.
; Unfortunately, neither hibernation nor brumation are options naturally available to humans. (Humans, that is, except for one Japanese office worker in need of GPS assistance.) But what if it were? After all, animals do it. If we can figure out their secret, then maybe we can teach people to hibernate too.
SPARROWS, “OWZELS,” AND RADIOACTIVE GROUNDHOGS: THE EARLY SCIENCE OF HIBERNATION
The question of how animals hibernate appeared as far back as 350 BCE, when Aristotle became curious about how some of our animal friends spend the cold, dark days of winter. For instance, he tells us with ponderous authority that hibernation is widespread among birds. Many, he reports “decline the trouble of migration and simply hide themselves where they are.”
Put that way, Aristotle sounds eminently sensible. Indeed, why face the exigencies of air travel? Why not simply take a nap?
Alas, his observations are perhaps overly broad. “And with regard to this phenomenon of periodic torpor,” he opines, “there is no distinction observed, whether the talons of a bird be crooked or straight; for instance, the stork, the owzel, the turtle-dove, and the lark, all go into hiding.”
I can’t comment on the wintering habits of “owzels,” whatever they are. But I can report categorically that none of the other birds Aristotle mentions really sleep away the winter. In fact, only one species of bird is known to hibernate: the Common Poorwill (Phalaenoptilus nuttallii).
Meanwhile, the swallow, to which Aristotle devotes an inordinate amount of text, here and elsewhere, does not. Aristotle had a strained relationship with birds in general, and swallows in particular. “If you prick out the eyes of swallow chicks while they are yet young,” he reports cheerfully, “the birds will get well again and will see by and by.” I’d advise taking Aristotle’s avian observations with a grain of salt.
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