Airway Clearance and Cough Assist in Duchenne Muscular Dystrophy

Airway clearance is the set of techniques that help move mucus out of the lungs when a person cannot cough strongly on their own, and in Duchenne muscular dystrophy it becomes one of the most important parts of respiratory care. As the breathing muscles weaken, the cough weakens too. A weak cough is the main reason a common cold can turn into a chest infection that needs hospital care.

This post explains why cough matters in Duchenne and what tools and techniques help. Any individual respiratory plan belongs to the care team.

Why a weak cough is the real risk

Most people clear mucus and germs from the lungs by coughing. A strong cough needs three things: a deep breath in, a tight closure of the airway, and strong abdominal and chest muscles to push the air out fast. Duchenne weakens the muscles that power the breath in and the push out.

The result is that everyday respiratory infections become more dangerous, not because the infection itself is worse, but because the lungs cannot clear themselves. Many serious respiratory events in Duchenne happen during otherwise ordinary colds.

How cough strength is measured

Care teams can measure cough strength, often with a simple test called peak cough flow. Tracking it over time, and especially during illness, helps the team know when extra support is needed. Respiratory surveillance, including measures of cough and breathing strength, is part of standard Duchenne care. (Birnkrant et al., DMD Care Considerations Part 2 (respiratory), Lancet Neurology 2018)

When peak cough flow falls below set thresholds, guidelines recommend introducing assisted cough techniques.

Manual assisted coughing

The simplest help is manual assisted coughing. A trained caregiver or therapist times a firm push on the abdomen or chest with the person’s own cough attempt, adding force to the push. Breath-stacking, where several breaths are taken in before a cough, can also increase the volume of air available.

These techniques are taught by a physiotherapist or respiratory therapist and can be done at home. For background, see physical therapy in DMD.

Mechanical cough assist

When manual techniques are not enough, a mechanical device can help. Mechanical insufflation-exsufflation, often called a cough assist machine, delivers a deep breath in and then quickly reverses to a strong pull, mimicking a natural cough and bringing mucus up where it can be cleared.

International respiratory guidance for Duchenne supports the use of assisted cough techniques and mechanical cough assist as breathing weakens. (Respiratory care of the patient with Duchenne muscular dystrophy: ATS consensus statement, PubMed) Many families keep a device at home and use it daily during infections.

Pairing airway clearance with ventilation

Airway clearance works alongside, not instead of, breathing support. Many people with Duchenne use non-invasive ventilation at night and sometimes during the day, and the two are managed together. For background, see sleep in DMD and respiratory care in DMD.

During an infection, the care team may increase ventilation and airway clearance together, and may lower the threshold for assessment. For background, see managing illness days at home in DMD.

Planning for sick days

The time to learn airway clearance is before it is urgently needed. Families often prepare by learning the techniques while well, keeping any prescribed device charged and accessible, and agreeing a plan with the team for what to do when a cold starts. For background, see emergency preparedness for DMD families.

A written sick-day plan that includes airway clearance, ventilation, and when to seek help turns a frightening moment into a familiar routine.

What is still uncertain

The exact thresholds and schedules for airway clearance vary between centres, and the best combination of techniques for a given person is individual. What is consistent across guidance is that supporting a weak cough is central to keeping people with Duchenne out of hospital and well during infections.

For related reading, see respiratory care in DMD, sleep in DMD, managing illness days at home in DMD, emergency preparedness for DMD families, and the reported piece When Time Is Stealing Your Child.

Disclaimer: This post is informational and does not constitute medical advice. Decisions about diagnosis or treatment must be made with a qualified care team.