The Deepest Sleep

Illustration by Alan Dye

Sometimes I dream of general anesthesia. I’ve never had it—in fact, between having a reasonably high threshold for pain and a typical doctor’s anxiety about letting myself be a patient, I’ve tended to go for rather minimal pain control, fighting every step of the way to stay in charge and call what shots I can (no pun intended). But a couple of years ago, I was given some midazolam, a short-acting benzodiazepine and a relative of Valium, to relax me before a minor surgical procedure. The minute the drug went in through the IV, I closed my eyes and the world went away, and that half-hour, or hour, or hour and a half (who knows?) disappeared from my life. So ever since then, I occasionally wonder how I would feel about handing over the whole enterprise—anxiety, sensation, consciousness, and memory.

As a medical student in the eighties, I thought my brief rotation through anesthesiology was mostly about the airway—the anesthesiologists were superbly skilled with the breathing tube and the ventilator, and I remember those ritualized moments of induction: the administration of general anesthesia, the matter-of-fact responsibility of slipping the plastic tube into the patient and beginning to breathe for him. I identified with the doctor, and I envied that skill. But more recently, as my body ages, I’ve wondered what the patient is experiencing—what we escape into when we confront those moments we will be grateful to miss.

This is your brain on drugs, as the saying goes. Induction, done by gas or IV, takes you simultaneously out of awareness and pain-sensation—and into unconsciousness. The muscles relax, and the eyes stop moving. The body stops protecting itself, even against something as simple as cold. When you’re asleep, if the room gets chilly, your peripheral blood vessels constrict, sending extra blood to your important organs; if the room gets cold enough, you huddle under your blanket, or wake up. Under anesthesia, you do none of these things. You don’t protect your airway, you don’t respond to loud noises, and you don’t feel pain—which, of course, is the whole point.

If you go even deeper down—if the anesthesia doses increase—you begin to lose autonomic function, the involuntary actions of the body that, for example, keep the heart beating. That’s a more profoundly anesthetized state than the anesthesiologists would like; their goal is to keep you sufficiently below the surface but safely out of danger.

But what is up and what is down? What is on top of you, when you are under anesthesia? How are we to understand this state, in which understanding disappears, sensory perceptions are blocked, and even memory is altered?

In my own not completely organized thinking, the fantasy of anesthesia was one of healing, restorative sleep, sleep that took you to a place where you would not toss and turn and you could not be disturbed. But as I learned more about anesthesia, that came to seem like a poor approximation. I spoke to Dr. Audrey Shafer, a professor of anesthesiology at Stanford and also a poet, who, over the course of her career, has written about her job in the operating room and about the significance of the metaphorical language used about going under. “Although we invoke the metaphor of sleep for anesthesia,” she told me, “they are separate states. It can be reassuring to talk with a patient about falling asleep—many are happy to fall asleep comfortably—but anesthesia is a chemically induced coma that doesn’t produce the same electroencephalographic pattern that sleep does.”

True unconsciousness, the great blessing of general anesthesia, and not to be confused with the sleepy overrelaxation that I experienced with a little benzodiazepine, is still sometimes meted out by inhalation of potent gases whose antecedents were discovered in the nineteenth century. It offered a release from the pain that had attended various aspects of human physiology and pathophysiology, from the normal (childbirth) to the disastrous (amputation). When Queen Victoria set her royal stamp of approval on childbirth by chloroform, she was not troubled by any sense of loss at missing the moment of delivery (to be fair, she didn’t use it until Nos. 8 and 9). Nowadays, the gifts of anesthesia have become multiple and specific: You can lose the pain and keep the experience, or lose the pain and the experience both without becoming technically unconscious, or you can enter true, temporary unresponsiveness.

The first surprise when you start talking to anesthesiologists is the matter-of-fact way they speak of the brain’s functions. Consciousness, sensation, memory are the latitude and longitude of their workdays. When anesthesiologists speak approvingly of a short-acting anti-anxiety drug that also provides good amnestic effects—that is, it prevents you from “laying down new memory”—their conversations have a cheerfully functional quality that doesn’t quite jibe with the way most of us think about the calculus of character and consciousness. In the anesthetized amnestic state, it’s not as if memory is made but somehow “erased”—no memory is ever created.

Anesthesiologists are supposed to acknowledge and confront the fears that going under calls up in many of us—and the two most basic fears run at cross-purposes: We are afraid that we will go to sleep and never wake up, and we fear insufficient oblivion, inadequate pain relief, waking up too soon during surgery. We fear going too deep and staying too shallow.

“People who know I’m an anesthesiologist say to me, ‘Oh, you don’t have to talk to people.’ In fact, I have five to ten minutes to talk to people and convince them to put their life in my hands,” says Dr. Marc Bloom, director of the neuroanesthesiology program and of perioperative technology at the NYU Medical Center.

And so the idea of being put out retains its power and its terror and its mystery. Interestingly, there is a persistent mystery at the center of this mystery, as nobody fully understands how general anesthesia works. The gases discovered in the nineteenth century have been superseded by more sophisticated and well-controlled drugs, but we don’t fully know, after all the research and all the improvements, exactly how general anesthesia does what it does. Your likely response to a cocktail of medication can be anticipated by your age and size and medical history, but all such predictions can be off, and much of an anesthesiologist’s job is delicate and creative, tending to the aspects of physiologic function and keeping you as deep as you need to be, but no deeper. “We’re navigating a narrow path,” says Bloom, “constantly balancing your blood gas, the autonomic nervous system, your blood pressure.”

There has been a good deal of discussion in anesthesiology in recent years about the value of using machines to monitor brain function during surgery. The BIS monitor, the first on the market, uses a strip of electrodes applied to the patient’s forehead to read brain activity during anesthesia. This kind of monitoring—an ongoing EEG that yields a single index number signaling consciousness—is meant to give the anesthesiologist a more sensitive way to prevent any episodes of awareness or unnecessarily heavy dosing; some doctors and operating rooms use it routinely, some reserve it for patients for whom anesthesia is a more high-risk situation, and others choose not to use it at all.

As patients and as doctors, then, we struggle to understand anesthesia through monitors and metaphors: that the brain is an organ, measurable and mechanical; that consciousness and thought are on some level rooted in cell function and electrical activity, but that this organ and those processes are the source of thought, complexity, memory, creativity, and personality. When I go under anesthesia, am I still myself? Even if I cannot recognize myself or perceive myself? How am I to think about that time passed in the operating room, time that will not register on my senses or exist in my memory? As Shafer notes, the language doctors use when the patient is still conscious—polite, considerate, professional—is different from when that same patient goes under, outside of the conversation, draped and represented on X-ray boxes or computers and monitors. She calls this “the spreading out of the patient by representation.”

I don’t think I can really imagine life or medicine back before anesthesia, when there was no way at all to skip the most agonizing trauma that life might deal. But there are primal fears and longings called up by this modern, matter-of-fact capacity to escape your connection to the world, and then safely return to yourself again. Anesthesia can conjure the peace of not-knowing, but it is a gift that comes with the fears of losing yourself, of diving down too deep. It is the allure and the terror of leaving yourself behind.

The Deepest Sleep