Medical Matters: Should we stop pointless investigations?

During a recent educational trip to Columbia University in New York, I met up with close friend from my medical school days. Tom and I hung around with another close friend in college. We were the three amigos, sharing the highs and lows of university life while enjoying some memorable japes and scrapes, as undergrads do.

It was great to spend time with Tom and his wife. He is a distinguished cardiologist in Pittsburgh and he and I were shooting the breeze about matters medical when he came up with an interesting question: is it time to stop listening with a stethoscope to the carotid arteries in the neck as part of routine physical examination?

Though I was initially taken aback at the notion of abandoning a centuries-old practice, his proposal fits in with a current trend of questioning some established practices in medicine. Recently, the UK Academy of Royal Medical Colleges asked doctors to consider drawing up a “not to-do” list of pointless investigations and inappropriate treatments. Among its suggestions is that we stop performing plain x-rays for low back pain – there is substantial evidence that the investigation contributes nothing to the initial diagnosis and management of the common problem. In an era of absorbable sutures, routine check-ups after minor surgery are hard to justify, as is the practice of washing out lacerations with costly saline when tap water is just as safe and effective.

Generations of medical students have been taught to listen to the carotid arteries as part of a physical examination in general and an assessment of the cardiovascular system in particular. Doctors listen out for a “whooshing” sound that we refer to as a bruit (after the French for noise); this vascular murmur can indicate a narrowing of the artery. Patients with significant narrowing (stenosis) were thought to be at risk of stroke and therefore required investigation with a view to possible operative intervention.

It turns out that while there is evidence for intervening surgically in patients who have symptoms that can be attributed to the vessel narrowing, there is no evidence the same is true for people with no symptoms whose bruits are detected as part of a routine examination. In fact, for asymptomatic patients, the risk of having a stroke during a procedure is greater than if they are left alone.

All of which led to Tom posing three pertinent questions: What should we do with asymptomatic patients? What does the presence of a bruit mean? What does the absence of a bruit mean?

Here are his thoughts: “Asymptomatic patients with vascular disease elsewhere should be managed aggressively, whether or not they have carotid disease. What about the patient with risk factors, but no established vascular disease? If he has a bruit, he should have his risk factors controlled but if he doesn’t have a bruit he should also have his risk factors controlled. Furthermore the absence of a bruit doesn’t exclude significant carotid stenosis . . . so don’t listen to the carotids.”

“And what of the patient with neither risk factors nor established vascular disease? If this patient has a bruit it is highly unlikely that he has carotid disease and even less likely that he will have a stroke. There is no indication to intervene . . . so don’t listen.”

The real core of the conundrum for me came with my friend’s point that “if you listen for a carotid bruit you can’t ‘unhear’ it . . . but can you ignore it?”

Carried through to its logical conclusion, his argument suggests we should question the value of teaching future doctors to routinely listen to the carotid arteries. It also suggests we are wasting large amounts of money on carrying out ultrasound testing on people with asymptomatic bruits.

And it begs the question: are we squandering even larger amounts of money on procedures to correct the blockage when the evidence points to a lack of benefit – or even harm – for some patients?