Shocked

by David Casarett

  My choice is made a little easier by the fact that the science behind this particular maneuver is plausible. In theory, at least, the trotting horse would provide the same sort of effect on a dead person’s chest that the compressions of CPR produce. In addition, that same up-and-down bouncing might move the chest wall enough to cause air to flow into and out of the lungs. But would it work?

  HORSEBACK-RIDING LESSONS

  A week later, I find myself looking up at a very large horse named Penny, and down at a compact, wiry horse trainer whom I’ve been instructed to call “D.” D doesn’t seem to talk, and he doesn’t smile. He doesn’t even have much facial expression at all. But on the bright side, he doesn’t seem to be fazed by my request to be strapped across the back of a trotting horse.

  It took me three failed attempts before I realized that calling a riding stable and asking point-blank to be strapped to the back of a trotting horse was bound to end in disappointment. Finally, I got an appointment by asking if they offered riding lessons, without being very specific about exactly what I had in mind. The nice lady on the phone agreed, not entirely aware of what she was agreeing to. Alas, neither was I.

  So there I am, standing in the middle of a round, dirt-floor riding arena that’s about 100 feet in diameter. There’s a sturdy wooden partition around the edge to prevent horses from escaping, which offers me some degree of reassurance. There are also half a dozen horsey people watching us surreptitiously, which doesn’t. Out of the corner of my eye, I think I see a child point at me and laugh. I begin to suspect maybe this isn’t such a good idea.

  Actually, I’m pretty sure this isn’t a good idea. In the past week, I’d e-mailed several colleagues, hoping to get some sense of what this exercise might entail. They weren’t encouraging. Their answers ranged from pointed questions about my maturity (“Does your family know you’re doing this?”) to dire warnings about potential side effects, including a nosebleed, heartburn, nausea, cardiac arrhythmia, and respiratory arrest.

  I’m hoping I can get away with just a nosebleed. That would be harmless but impressive. I’m decidedly less enthusiastic about the other possibilities.

  D points to my left foot, and then to Penny’s left stirrup. Then he points to my left foot again, just in case it wasn’t quite clear what’s expected of me. Carefully navigating around a pile of steaming manure that lies in front of Penny’s left rear hoof, I do as I’m told. A moment later I find myself draped over Penny’s back, my cheek flattened against a dirty blanket that has the texture of greasy steel wool. D is tying my feet to my wrists under Penny’s belly. I’m guessing he’s improvising, but he seems confident.

  The world, meanwhile, has turned upside down. Then D gives Penny’s rump a hearty slap. Then the upside-down world starts to move.

  Slowly at first, in lurching bumps. Then Penny’s pace quickens and we’re trotting merrily around the paddock. My head is on the inside of the circle and my feet are on the outside, which means I’ve lost sight of D and everything else, for that matter. All I can see is Penny’s muscular right haunch, swinging back and forth like a pendulum. A very energetic pendulum.

  The sensation of being trotted around a riding arena isn’t entirely unpleasant at first. There’s even something rhythmically hypnotic about being bounced up and down, and up and down. In fact, it’s relaxing me enough that my sense of time is getting hazy. I can’t tell whether I’ve been trotting for a minute or five, although some part of my brain is still making a mental note whenever we pass the pile of horse manure I almost stepped in when Penny and I were first introduced. That landmark has appeared two times so far, which means two circuits around the ring.

  At some invisible signal from D, Penny’s rhythm shifts into a higher gear, and the ride is no longer a lulling bounce. It is, I’m thinking, more like how you might feel if a basketball is being dribbled on your stomach. By a very large man with hubcap-size hands. Who has an anger management problem.

  This is my first thought.

  My second thought is that it’s becoming difficult to breathe. Very difficult. As in: “Help! Help! Oh my God, I’m going to die!” That kind of difficult.

  After a few panicked moments of hyperventilation that do no good whatsoever, I stop trying to breathe. I just stop. And I even relax a bit. Hypoxia, I’m told, has that effect on people. At least, it does on me.

  But then something interesting happens.

  When I was trying to breathe on my own, I was fighting Penny. And Penny, needless to say, was winning. But as soon as I relax, and stop trying to breathe at all, I’ve discovered that Penny—bless her heart—is breathing for me. In and out, in little, panting dog breaths. Big enough breaths, it seems, to move some oxygen. Big enough breaths, apparently, to keep me alive.

  But how does that work? 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.

  Indeed, this seems to work. Chalk one up for the Royal Humane Society. 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. As carbon dioxide builds up, it turns into carbonic acid in your blood, making your blood acidic. Although respectable medical textbooks will never describe the acidification process in these terms, you can think of it as somewhat like mainlining Pop Rocks. This, in turn, wreaks havoc on your body. Also, to add insult to injury, high carbon-dioxide levels make you feel short of breath, even if you’re getting enough oxygen.

  These, anyway, are the little lessons in physiology that are flitting through my fading brain as I remember that to get rid of carbon dioxide, we need to take deep, full—and slow—breaths. That’s something I most certainly am not doing. Apparently, Penny has not been schooled in the mechanics of respiration and gas exchange, and so it seems that her graceful trotting is going to kill me.

  Carbon dioxide was first described by a Scot, James Black, who carried out all sorts of cunning experiments involving weights and balances and balloons that I’m finding very difficult to remember as I continue to be bounced along by Penny. He called carbon dioxide “fixed air.” He lived to be seventy-one. He never married but had numerous very close male friends. Odd what facts you remember when you’re on the verge of blacking out.

  I try waving at D, only to realize that my hands are tied. That this comes as a surprise to me should give you some sense of my cognitive state. It should also be a warning, just in case you still need one, that my little riding experiment is one that you really, really don’t want to try.

  After what seems like a lifetime, Penny’s pace slows, D’s boots reappear, and I start breathing for myself again.

  As Penny downshifts to a walk, I can’t help noticing that she isn’t even breathing hard. On the other hand, I’m gasping like a beached fish. Or like someone who was very close to becoming “apparently dead.” As we stop, D l
oops Penny’s reins over a post and unties me.

  I stand tall and stretch. I pat Penny’s flank with what I imagine is a horsey gesture. Then I throw up, violently and copiously, narrowly missing D’s boots but splattering my own sneakers beyond redemption.

  Penny seems unperturbed, but D takes a step back, impressed. I’m more than a little lightheaded, and mostly just trying to stay upright. But I swear, just for a second, I see him smile.

  FEATHERS, WHIPS, AND ICE: THE EARLY SCIENCE OF RESUSCITATION

  That was not my finest hour. But at least Penny seemed to have enjoyed her little romp. And I’d certainly brightened D’s day.

  More important, I learned something. If you’re relaxed enough—that is, if you’re hypoxic enough to be semiconscious—the trotting motion of a horse might actually breathe for you. At least for a little while. On the other hand, it seems unlikely that fine animals like Penny will ever have a place on a hospital’s “Code Blue” team.

  But the British Society did have some successes. Remember its report of fifteen lives saved in the summer of 1884? Something in their toolkit must have worked.

  What about fumigating someone’s orifices with tobacco smoke, for instance? Those methods, at least, are straightforward. As pioneered by the Dutch, a rescuer lights up a pipe and blows smoke directly into the victim’s mouth, nostrils, or rectum.

  If we set aside that last option—and please let’s do—there’s a certain appeal to arriving at a scene of crisis, only to pause, remove a briar wood pipe from one’s waistcoat pocket, and embark on the little rituals of filling, tamping, lighting, and puffing. That sort of routine would surely have a calming effect on panicked bystanders and family members, which should be reason enough to try it. But did it work?

  It might have. Nicotine, the ingredient of tobacco with the most prominent cardiovascular effects, belongs to a class of chemicals known as alkaloids (of which cocaine is one) that come from the nightshade family. It’s also absorbed through mucous membranes in the mouth (or rectum). So far, so good.

  The most important thing to know about nicotine, though, is that it’s very rapidly absorbed. Usually nicotine exists in a non-ionized form that crosses mucous membranes into the bloodstream very quickly. It also crosses from the bloodstream into the brain with a similar rapidity. The result is that smoke blown into someone’s mouth will reach the heart and brain in a matter of seconds, presuming there is enough heart function to keep blood flowing. (That’s not the case if the nicotine is in an acidic environment, like the stomach, from which it is not well absorbed.)

  Nicotinic receptors exist throughout the brain and in the peripheral nervous system, but nicotine has a much higher affinity for brain receptors. That means that although the nicotine you inhale in a cigarette could act anywhere in the body, its effects are mostly felt in the brain. The one exception is that nicotine binds avidly to neurons in the sympathetic nervous system that activate the adrenal glands, releasing epinephrine. Epinephrine causes an increase in heart rate and respiration, as well as an increase in the strength of the heart’s contractions. Not surprisingly, injectable epinephrine is one of the key items on resuscitation carts.

  So tobacco smoke is certainly a plausible way to revive someone. And that’s particularly true in the setting of drowning, because a series of interlocking reflexes effectively dampens the heart’s activity. Cold water applied to the face, for instance, causes a drop in heart rate—the so-called diving reflex. Indeed, some people pulled from particularly cold water have a heart rate of only a few beats per minute (a normal rate is from 60 to 100 beats per minute). In those circumstances, a jolt from the sympathetic nervous system is exactly what the heart needs. So it’s plausible that tobacco smoke might have been at least partially effective. It probably wouldn’t have restarted a heart that had stopped completely. But if a drowning victim had a very slow and weak pulse—perhaps slow enough to be undetectable to a bystander—tobacco smoke might have increased the heart’s activity to give the appearance of resuscitation.

  Sadly, enthusiasm for blowing smoke into various orifices declined sharply in 1811 because of a killjoy named Sir Benjamin Brodie. Brodie was an English physiologist and surgeon who doubtless had numerous positive traits, but he almost certainly was not an animal lover. In a series of experiments on dogs and cats, Brodie claimed to have determined that tobacco smoke is potentially lethal, and he even identified the lethal dose. (Just in case you’re wondering, it’s four ounces for dogs, and one ounce for cats.) Despite the fact that no one was seriously suggesting that tobacco smoke be used to resuscitate family pets, people generalized Brodie’s findings to humans and decided that the whole smoke-blowing strategy was probably best avoided entirely. Such was the state of evidence at that point in history when shrill activism by someone like Brodie was enough to change clinical practice. In the absence of randomized controlled trials showing that tobacco smoke was safe and effective, its proponents found it easier to cave in to popular opinion.

  That’s too bad, because as we proceed down the list of potential resuscitation techniques, evidence of effectiveness gets pretty thin. For instance, another widely used method—flagellation—seems to have very little to recommend it. Beating a drowning victim with whips apparently seemed like a good idea to someone, but the historical record is noticeably—and sadly—silent as to whom that someone was. The best that can be said for this approach, I suppose, is that if the person doesn’t wake up, well, no harm done.

  Another technique advocated by early resuscitation enthusiasts was that trick of tickling the victim’s throat with a feather. Unlike with flagellation, where if the victim actually revives during the beating he or she will be quite sore or perhaps have a broken bone or two, the feather technique is likely to do more harm than good. Activating the gag reflex when someone is unconscious, or semiconscious, can lead to vomiting and subsequent inhalation of stomach contents. This unfortunate series of events is known in medical circles as aspiration pneumonitis, which is often rapidly fatal.

  If that doesn’t kill you, there’s a good chance that activating the gag reflex will stimulate the vagus nerve, which reduces the heart rate. Actually, the gag reflex has much the same effect on heart rate and respiration that drowning does, and thus is likely to make a bad situation worse. So feathers, sadly, are out.

  It’s at this point that you have to wonder—if the British Society took such careful notes, how could some of its recommendations be so implausible? In part, the problem was that many of these resuscitations were reported by people with little or no medical training. So the techniques that were used may have varied widely. More important, without the sorts of tools we have today—an electrocardiogram, a heart-rate monitor, even a stethoscope—it’s difficult to tell for sure what these interventions actually accomplished. If a drowning victim like Anne Wortman, who was tickled with a feather, woke up, did that feather restart her heart? Or was she simply unconscious, and did the gag reflex wake her up? The British Society didn’t know, and so it probably counted many cases of unconsciousness as examples of successful resuscitation.

  That lack of good evidence explains the presence of two common—and contradictory—views of the role that temperature plays in a successful resuscitation. On one hand, the Royal Humane Society was strident in expressing its opinion that the apparently dead should be warmed in the quickest way possible. Immersion in warm water was frequently recommended, as was using blankets, warm sand, or placing the victim next to a fire. The Society—forgetting for a moment its stern Victorian moral code—even recommended the use of volunteers who would climb into bed with the apparently dead. It’s not clear whether these volunteers were supposed to be fully clothed, but that’s probably best left to the imagination.

  On the other hand, at roughly the same time, others proposed what was known, somewhat ominously, as the Russian Method. Rather than putting the victim in bed with his or her fellows, the Russians appar
ently believed that cold was better. So they would pack victims in ice or cold water. Or they would simply toss them outside.

  One has to wonder whether anyone believed that these chilling maneuvers improved a victim’s chances. Indeed, it sounds like an ideal ploy to get rid of an enemy, mother-in-law, or czarina. “Don’t worry,” someone might say, “we’ll just put Catherine outside in the snow. She’ll feel better in no time. Really.”

  It turns out that both approaches have something to recommend them. Drowning, for instance, often results in hypothermia—a core body temperature that is 5 or even 10 degrees below the normal 98.6 degrees. Hypothermia is a problem because it reduces the heart rate and respiratory rate. Profound hypothermia, below 93 degrees, also makes the heart’s electrical conduction very fragile. It’s easily disrupted, and very difficult to convert to a normal rhythm. So there is something to be said for warming a cold drowning victim, since doing so makes it easier to restart the heart. Indeed, there’s a saying in emergency medicine that a hypothermic victim who is found unconscious and believed to be dead isn’t dead until he’s warm and dead.

  But the Russians weren’t entirely wrong, either. It’s true, cold will make it more difficult to restart a heart. But as we’ll see in chapter 3, hypothermia can protect the brain and other organs by making them less susceptible to damage caused by low levels of oxygen and the subsequent buildup of toxic chemicals and free radicals that can damage tissue.

  That debate, in a nutshell, is perhaps the principal conundrum of the science of resuscitation. Colder temperatures make it more difficult to revive a person, increasing the probability that someone who is apparently dead will become truly dead. However, warmer temperatures allow damage to the brain, increasing the likelihood that we’ll wake up—if we wake up at all—with the IQ of a Snickers bar.