Even to its practitioners, there are things about anaesthesia that remain a mystery – such as, where exactly it fits on the spectrum of consciousness.
A state of general anaesthesia is rendered not by a single drug, but by a lights-out cocktail comprising a “hypnotic” to induce unconsciousness, an analgesic for pain control, and, often, a muscle relaxant to keep the patient still. Among the hypnotics are ether, nitrous oxide (laughing gas) and ketamine, drugs also used recreationally for their mind-altering qualities. The muscle blockers that immobilise patients on the operating table derive from curare, the substance that once tipped poison arrows and caused death by paralysis.
Before curare was introduced to anaesthetics in 1942, patients had to be more heavily drugged to ensure that they didn’t flinch or squirm during delicate surgery. The high dose suppressed not just consciousness but heart and lung function, so that anaesthetic-related deaths were not uncommon. With curare in the mix, a lighter anaesthetic could be given and mortality rates plummeted. In the decades since, new drugs and monitoring techniques have made it possible to further reduce the dose of anaesthesia, resulting in fewer complications and faster recovery. When the dose is reduced, so is the depth of anaesthesia, suspending the patient nearer the surface of consciousness during surgery.
Kate Cole-Adams recounts the story of Rachel, the friend of a friend, who “woke” from a general anaesthetic while undergoing a caesarean. The action of the muscle-blocker left her incapable of signalling that she was conscious and in pain. Cole-Adams, a journalist, set out to investigate the condition known to anaesthetists as “accidental awareness”. She had supposed that anaesthesia produced a deep, unshakeable slumber from which surfacing, if it happened, must be a rare and fleeting occurrence. What she discovered would shock her; in fact, it would change her. Anaesthesia is, in no small part, a personal odyssey.
Waking during surgery – though, really, “waking” doesn’t seem the right word for it – is more common than most of us imagine. Sometimes, as in Rachel’s case, no one but the patient is aware that she is conscious; often, the anaesthetist, detecting a patient’s stirring, will adjust the dose to send her further under. But longstanding studies show that, however effective the anaesthesia, it cannot be assumed that a patient’s faculties are fully extinguished. Things said in the operating theatre – remarks about the patient’s body, or her prognosis – can lodge in her unconscious. “One theory,” writes Cole-Adams, “is that, under anaesthesia, the stress hormones that surge into the bloodstream when a doctor cuts us might activate the amygdala and increase our chances of learning information, albeit without knowing it.” She suggests that a sign be posted in every operating theatre: THE PATIENT CAN HEAR.
Some patients, such as Rachel, who surface or are otherwise aware during surgery, experience post-traumatic stress. Others may suffer ongoing psychological problems, even if they have no memory of the episode. Lingering after-effects of “accidental awareness” mostly result from recollecting the nightmarish sensation of paralysis, which has been likened to being trapped under water or beneath a sheet of glass, or else a taste of some terrifying afterlife. Research finds that the trauma can largely be assuaged if patients are told ahead of time that “they might briefly wake and find themselves unable to move, and that this would pass”.
A British researcher who studied awareness among women undergoing major gynaecological surgery concluded that, since unconsciousness and freedom from pain could not be guaranteed, “general anaesthesia” was a misnomer – the word anaesthesia, after all, means “without feeling”. Better, he said, to acknowledge that the aim is for the patient to have “no recognisable recall of surgery” and call it instead “general amnesia”.
Anaesthesia’s “gift of oblivion”, then, may owe less to unconsciousness than to amnesia. How should we feel about that? Does it matter that we experience pain or trauma, provided we have no memory of it?
Questions like these haunt Cole-Adams, and her tenacious exploration of what anaesthesia is and is not leads her deep into provinces that share its bleary borders: dreams, memory, the nature of consciousness. Events and retrieved memories from her own life surface in fragments amid discussion of clinical research, brain states, anaesthetic processes. Only in the closing chapters do these fragments, or rather their narrative function, cohere:
In the end, the most important thing we bring to surgery is ourselves. Not just our diagnoses and prognoses, but the whole squirming bag. History, culture, psychology, stories, fears.
As well as subjecting herself to unflinching excavation and exposure – a kind of surgery of the psycho-epistemological tract – Cole-Adams struggles with the recalcitrance of the writing process:
Every time I sat down I seemed to disappear.… Each thought seemed to take an infinity. Each connection felt like the forcing together of negative poles.
But clarity does come, in exquisite observations such as this, in the moments after her mother’s death: “a magpie called outside the window, and a shaft of light shredded the glass and landed bam on her face, like in a painting”.
The book builds towards Cole-Adams’ own experience of anaesthesia during major surgery in 2010, by which time, after more than a decade’s research, she knew far more than was good for her about the possibility of waking on the operating table. She knew, too, that “one of the strange things about anaesthetic drugs is that they can exert their effect in each direction”, putting distance not only between the patient and her pain, but also between surgical staff and patient: her unconsciousness a kind of absence that made her easier to cut.
Even so, Cole-Adams resolves to enter the backwards-count with a sense of herself as “an active participant in my own surgery”. For, as she quotes the pioneer neurologist, John Hughlings Jackson, “There is no such entity as consciousness: we are from moment to moment differently conscious.” FL
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This article was first published in the print edition of The Saturday Paper on May 27, 2017 as "Kate Cole-Adams, Anaesthesia". Subscribe here.