Smart Reads: David Casarett’s ‘Shocked’

Death and life might seem like pretty stark categories, but modern science is finding ways to bring people who are, as Miracle Max might say, only “mostly dead,” back from the brink. We got a chance to talk with University of Pennsylvania physician David Casarett, whose new book Shocked: Adventures in Bringing Back the Recently Dead explores techniques of resuscitation from the outlandish (blowing smoke up where the sun don’t shine) to the cutting-edge (cooling and cryopreservation):

(Note: This interview has been lightly edited for clarity and length.)

WSF: How do you define death, as a physician?

DC: It used to be pretty easy to determine when somebody was dead: You’d look at them, watch them for a few minutes. If there was no heartbeat, no breathing, they’d be dead. The longer somebody goes without any of those signs of life, the more certain you are that they are brain-dead, which is the legal definition.

But things over the last 20 or 30 years have gotten confusing. In the book I tell the story of Michelle Funk, who was two and a half years old when she fell into a creek and drowned, and spent about 3 hours without any signs of heartbeat or breathing. For two of those hours she got efforts at resuscitation, but for an hour she got nothing. She survived, and is doing very well today. So, before that happened, anyone would have said if someone’s been in the water for an hour, no heartbeat, they’re dead. But then Funk died, and she came back to life.

WSF: Cold played a role in that, right?

DC: It’s really interesting; of the many weird techniques of resuscitation tried over the years, cold may be the most effective. Back in the 1700s, the technique of burying people in snow was known, kind of ominously, as the “Russian method.” But it turns out that cold is a really good way of helping people survive.

The science there is really elegant and really simple: The colder a body is, the slower the metabolism is. So if you cool them down, you kind of trick that person’s body and brain into a state like hibernation, in which that body and that brain are using much less oxygen—so you can survive longer without oxygen.

WSF: Do you have to cool the whole body, or just the head?

DC: In theory, you want to cool the entire body, but what really matters—the cells that are really sensitive to going without oxygen—are the brain cells. If your right big toe goes without oxygen for a while, it’s not the end of the world.

WSF: You investigate a lot of wacky historical methods of resuscitation in the book. Were there any you were surprised to find actually worked?

DC: Some, like the Russian method mentioned previously, are effective. But as for my personal favorite resuscitation method—throwing people over the back of a horse—it’s difficult to see how that might have worked.

WSF: I guess it just has to work on just one guy for people to recommend it…

DC: When you think of resuscitation science 200 years ago, it really seems like a Wild West where people were trying just about anything: rubbing people with ammonia, whipping them, climbing into bed with them. There wasn’t much they didn’t try.

Both the Amsterdam Society and what became the Royal Humane Society kept records of which resuscitation techniques worked and which didn’t. But they just put the word out to potential rescuers to tell them what they did. So there’s a bias there. If you tried throwing somebody over the back of a horse and it didn’t work, you probably didn’t write in.

WSF: What sorts of patients will we be able to resuscitate 50 years from now that we can’t bring back today?

DC: There will be more people we can bring back—think the typical guy who falls down with a heart attack on the tennis court. We’ve actually made a lot of progress in resuscitating these types of patients, not because of huge advances in technology (although there have been some, like external defibrillators) but because there’s more awareness, more people trained in CPR.

One of the biggest hopes and opportunities in the future is for suspended animation. That’s an area of science where we’re poised for a big breakthrough.

WSF: You touch on cryopreservation, which still seems like something of a pipe dream…

DC: It does seem loopy, but it’s not totally crazy. There are examples from nature, like the wood frog that manages to let itself freeze in the winter. It produces a natural antifreeze that keeps ice crystals from forming inside it. But its heart stops. And in the spring, its heart restarts and it hops merrily away.

I went to a cryonics conference, where some people have already put the money down to be frozen—$70,000 for a head, or $200,000 for a body. I expected them to be kind of deluded, but many people realize it’s a long shot. As one person told me, “I know it’s an experiment, but I’d rather be in the experimental group than the control group.”

Check out this excerpt from ‘Shocked,’ where Casarett investigates an unconventional method of resuscitating the dead: tying a recently expired person to the back of a trotting horse:

The mechanics of breathing are really pretty simple, and it wouldn’t be difficult to replicate them with a horse. We breathe mostly with our diaphragm—a web of muscle that stretches across the lower edge of the rib cage, separating the chest from the abdomen. When the diaphragm contracts, it creates negative pressure (a vacuum) in the chest cavity. That drop in pressure causes the lung’s alveoli (small air sacs in the lungs) to pop open, pulling air in through the trachea. When the diaphragm relaxes, the pressure increases and air flows back out.

A horse can’t reproduce the diaphragm’s natural movement, but it can move the diaphragm and chest wall in a similar way. For instance, as the horse’s back rises, it presses in on the abdomen, forcing air out of  the lungs. It has much the same effect on the chest wall, pushing in and further emptying the lungs. Then, in the second or so that an inert body is bounced up and is airborne over the horse’s back, the diaphragm and chest wall bounce back to their usual shape, causing air to flow back in.

The trotting-horse method sounds like it might be a success…well, only a partial success. Because taking in oxygen is only half the work of breathing. The other half, getting rid of carbon dioxide, is just as important as the first, because too much carbon dioxide will kill you just as quickly as not enough oxygen will…

Reprinted from SHOCKED: Adventures in Bringing Back the Recently Dead by David Casarett with permission of Current, a member of Penguin Group (USA) LLC, A Penguin Random House Company. Copyright (c) David Casarett, 2014.