One in five patients who have the most common type of stroke don't get recommended screenings to see if the episode damaged their ability to swallow, a recent study in Canada suggests.

Under widely endorsed treatment guidelines, stroke patients are supposed to be screened for what's known as dysphagia, or an inability to swallow, before they receive any food or drink.

Stroke patients with dysphagia have a higher risk of pneumonia, dehydration, disability and death than people who don't have difficulty swallowing, previous research has shown.

For the current study, researchers examined data on 6,677 patients hospitalized with ischemic stroke, which results from an obstruction in a blood vessel supplying the brain.

None of the patients were getting support like feeding or breathing tubes that would make them ineligible for dysphagia screening.

Palliative care right to die

Stroke patients with dysphagia have a higher risk of pneumonia, dehydration, disability and death. (Getty Images/Cultura RF)

Within 72 hours of arriving at the hospital, 1,280 patients, or about 19 per cent, didn't get screened, researchers report in Stroke.

Omission of screening mainly occurs in patients with mild strokes, who are only half as likely as patients with more severe strokes to receive screening, said lead study author Dr. Raed Joundi, a neurology researcher at the University of Toronto.

Test needed even in people with mild stroke

Failing a dysphagia screening test increases the risk of poor outcomes — including death, disability, complications — as much as other major prognostic factors like older age and severe stroke, and is true even in people with mild strokes, Joundi said by email.

Elderly people who were at least 80 years old were 44 per cent more likely to get checked for dysphagia than patients under 60. People admitted to the intensive care unit were 56 per cent more likely to receive screening, and patients on a stroke unit had more than double the likelihood compared to those on a regular ward.

Among the 5,144 patients who had a documented dysphagia screening in their medical records, nearly half failed the test. After a severe stroke, 83 per cent of patients failed dysphagia screening, compared with 63 per cent of patients who had moderate stroke and 33 per cent with mild stroke.

Individuals who failed the screening tended to be older and have more chronic medical issues including dementia prior to the stroke.

When they failed the tests, patients were more than four times as likely to develop pneumonia. They also had more than five times the odds of severe disability and were more than twice as likely to be sent to a nursing home or rehabilitation facility after they left the hospital.

Screening efforts need improvement

One limitation of the study is that medical records might have failed to document screenings done for some patients or any tests done outside the 72-hour window examined, the authors note.

Still, it's likely the results would be similar for patients outside of Canada and for people who have less common hemorrhagic stroke, which occurs when a weakened blood vessel ruptures, Joundi said.

And the findings suggest that screening efforts need improvement, said Dr. Daniel Lackland, a neurology researcher at the Medical University of South Carolina in Charleston who wasn't involved in the study.

Patients and families should ask about screening, and they should alert doctors immediately to symptoms of dysphagia like difficulty starting to swallow, coughing or gagging while swallowing, drooling, weak voice, lost gag reflex or what's known as aspiration — food or drink getting into the lungs, Lackland advised.