Improving Care for Patients With Refractory Chronic Cough

Patients spend years trying to get help for a cough that won’t quit, according to clinicians and researchers speaking at the American Cough Conference during a session that, among other things, discussed the endotypes and phenotypes of individuals presenting with this condition, as well as a nonpharmacological strategy to control the urge to cough.

A little-known strategy called behavioral cough suppression therapy (BCST), taught by a trained speech language pathologist (SLP), can help some of these patients, according to Laurie Slovarp, PhD, CCC-SLP, associate professor at the University of Montana’s School of Speech, Language, Hearing and Occupational Sciences.

In the literature, these techniques go by many different names—such as respiratory retraining or cough-suppression physiotherapy. Studies have shown that up to 80% of patients, who have tried and failed the medical therapies that are currently available, can benefit from this kind of training, Slovarp said.

In her presentation, she described her approach when meeting with patients; it includes taking an extensive case history, conducting an oral mechanism exam, doing a voice evaluation, performing urge-to-cough testing, and administering a validated patient-report questionnaire.

Treatment consists of education, cough suppression training, increased awareness of cough triggers and pending cough, management of laryngopharyngeal reflux and postnasal drip, voice therapy, and a cough challenge if needed.

When Slovarp takes a history, she asks about the onset of the cough, and because most of the patients have been coughing for years, they typically don’t recall what started it.

“One thing that I think is interesting in talking to them about potential onset is many patients will tell me that for many, many years, most of their adulthood, they were prone to a prolonged cough after any sort of a cold, but eventually it would go away. But then the tipping point is, eventually one time it didn't go away,” Slovarp said. “They also will tell me that they would frequently get bronchitis, and then the other thing is dysphonia. And especially if they tell me that they would sometimes lose their voice completely after when they would get an upper respiratory infection.”

A trained SLP will also look at co-occurring functional disorders, including muscle tension dysphonia and paradoxical vocal fold motion, sometimes called induced differential obstruction.

Patients need to understand that it is safe to suppress a cough and that there is no benefit, and even negative adverse effects, from nonproductive coughs, she said. In addition, a key part of her job as a therapist is helping them realize that cough hypersensitivity is the reason for their cough, Slovarp said.

When she does start talking about cough hypersensitivity, most respond with, “Why has no one talked to me about this before,” or “That makes perfect sense.”

This therapy needs “buy-in” because patients, by the time they do see her, are skeptical, having been to numerous providers and having tried numerous medications or tests, Slovarp said.

The goal is to increase control and reduce the urge to cough, so that over time they will feel a reduction in the urge to cough. However, even when the therapy is considered successful, a bout with a respiratory infection or other illness may see it return.

Slovarp outlined the 5 strategies she uses to teach patients this method: cough-control breathing, relaxation techniques, cough suppression swallow, distraction, and resonant voicing.

For instance, cough-control breathing, she demonstrated, is a quick inhale through the nose and a long exhale through pursed lips, as if through a skinny coffee straw. Distraction might be throat lozenges, sipping water, or chewing gum.

Anecdotally, Slovarp has identified 6 factors that can help identify the best candidates for this treatment:

• Dry cough
• Laryngeal paresthesia
• Awareness of both cough triggers and when a pending cough is coming on
• Co-occurring dysphonia
• Co-occuring dyspnea suggestive of parodoxical vocal cord motion disorder
• Increased anxiety

“My goal is to change their nervous system so they don’t need to be on anything,” said Slovarp.

Earlier in the session, Jacky Smith, MB, ChB, FRCP, PhD, professor of respiratory medicine at the University of Manchester and an honorary consultant at Manchester University NHS Foundation Trust, discussed the differences to consider when thinking about phenotypes vs endotypes in these patients, noting that using an endotype-based approach will yield more precise treatment results.

Although patients with refractory chronic cough often show up in a doctor’s office with similar phenotypes, the underlying mechanisms of the disease are complex, which means there are limits to a phenotype-only approach.

For instance, phenotypes don’t tell you who will respond to therapy, she noted. If phenotypes separate chronic cough by categories of asthma, gastroesophageal reflux disease, nasal disease, or others, there is no place for cough hypersensitivity to fit.

“So existing phenotypes are not that helpful,” she said. Considering these patients on the basis of endotypes—where combinations of disease mechanisms are expressed in different degrees in patients with the same condition—can instead allow for a more individualized approach.

Patients with chronic cough have different cough drivers, levels of neuronal hyperexcitability and different types of nerve sensitization, and varying control levels over their cough. Understanding the degrees of the traits underlying the cough can help a provider better target treatment strategies, she said.