How Dangerous Is Obstructive Sleep Apnea During Surgery?
“There’s meaning in thy snores.” — Shakespeare
July 2, 2013 - 9:00 am
Shakespeare, on the whole, was in favor of sleep – at least if the opinions of his characters are any guide to his own opinion. “He that sleeps feels not the toothache,” says the Gaoler in Cymbeline. Sleep, says Macbeth:
… knits up the ravell’d sleave of care
The death of each day’s life, sore labour’s bath,
Balm of hurt minds, great nature’s second course,
Chief nourisher in life’s feast.
By contrast, not to sleep is a torment. Shakespeare must have known insomnia, for in Sonnet XXVII he says:
Weary with toil, I haste me to my bed…
But then begins the journey in my head…
And keeps my drooping eyelids open wide,
Looking on darkness which the blind do see.
Shakespeare also knew that “there’s meaning in thy snores,” though perhaps not the meaning that doctors now attach to them. They often mean obstructive sleep apnea (OSA), when sleep, which should be “death’s counterfeit,” becomes death’s possible harbinger, in the form of heart attacks and strokes.
According to a recent article in the New England Journal of Medicine, between a fifth and a quarter of the American population suffer from OSA, and this poses a risk, whose magnitude is not precisely known, to patients undergoing surgical procedures. The reason the magnitude is not precisely known is that it is difficult to control for obesity: not all people who are fat have OSA, and not all people who have OSA are fat, but there is a strong correlation, almost certainly a causative one. What the authors of the article call “the epidemic” of OSA – yet another epidemic of a non-contagious risk factor – is really an “epidemic” of obesity. A higher proportion of patients undergoing surgery than in the rest of the population have OSA: not surprisingly, 80 percent of patients being operated on for their obesity have it. All in all, perhaps 10 million operations are performed in America annually on people with OSA.
If OSA poses a risk to patients undergoing surgery, what should surgeons and anaesthesiologists do to reduce it? The trouble is that nobody knows yet. There are various suggestions such as that patients should undergo screening for ASO before operation and that they should be more closely monitored than others, and for longer, after operation. People with ASO who would otherwise be day cases should be admitted overnight. Perhaps they should receive treatment beforehand such as positive airway pressure therapy (PAP). But no one knows for how long they should receive it or even whether it would reduce postoperative risk. All that is really known is that something must be done.
That something is sure to be expensive, and one of the reasons something must be done is the threat of legal action. Doctors and hospitals might be held responsible for post-operative complications in patients with OSA if they did nothing to try to prevent them, even if it is not known scientifically what exactly they should have done to prevent them. This seems to me completely mad: first the sentence, then the verdict. What would be prevented by preventive treatment, therefore, are not medical complications but legal ones.
The authors conclude their article as follows:
Until we can better identify patients who are at risk and evidence-based interventions that improve outcomes… institutions should, at the very least, address the issue of OSA and develop protocols that take into account the need for heightened awareness as well as locally available resources.
This is a pure example of the something-must-be-done-ism that is epidemic – I use the term loosely or metaphorically – in political life. And what must be done is always to spend more and drive up costs.