Take a deep breath, but don’t take it for granted: Breathing and Duchenne Muscular Dystrophy
The following article appeared in the Ontario Physiotherapy Association’s newsletter.
There is a growing body of evidence that proper respiratory therapies and supports will improve life expectancy and quality of life for people with Duchenne Muscular Dystrophy (DMD).
- In a study of 157 people with Duchenne muscular dystrophy, patients who were not ventilated lived an average of 20.4 years, and patients who were ventilated lived an average of 31.0 years. (Konagaya et al, 2005)
- Respiratory failure in DMD often occurs as a result of the inability to cough during otherwise benign upper respiratory tract infections. The earlier that airway clearance is taught and practised, the less likely is early respiratory failure, pneumonia and death. (Finsterer, J., 2006; Bach,J., et al, 1997)
- Ventilatory support results in improved sleep, improved well-being and a slower rate of decline of pulmonary function (American Thoracic Society- Consensus Statement, 2004, 2009).
Given this evidence, we can understand the importance of focusing on respiratory care. Typically, when we first meet a boy with DMD, he is still mobile and his lungs are getting a healthy workout on a regular basis. As muscle weakness increases and he becomes less active, his vital capacity will become reduced.
Even at early stages of disease progression, it is important to facilitate maintenance of a strong cough. Blowing up a balloon is an effective way to practise and strengthen closure of the airway by the epiglottis. Blowing out candles reinforces the short, sharp blowing required for an effective cough. As the condition progress, therapeutic exercises may include blowing through a straw to move a cotton-ball around a table. (To make this exercise more fun, he can pretend to be playing a game of mini-soccer). Anything that demands a powerful burst from him will reinforce coughing strength.
Following the transition to using a wheelchair for mobility, it becomes very important to maintain an effective cough and range of movement in the chest wall and lungs. Teach parents how to reinforce the cough by using manual or mechanically-assisted cough techniques. Daily breath-stacking therapy has helped boys with DMD to maintain and, sometimes regain, their vital capacity. Breath-stacking – also known as “lung volume recruitment” – can be performed by taking a series of inhalations before exhaling or by using a modified resuscitation bag.
The physiotherapist should take an active, supportive role in the monitoring of respiratory function. The first signs and symptoms of hypoventilation are usually sleep-related: restless sleep, frequent turning, nightmares or waking in panic, morning headaches, nocturnal sweating. These signs and symptoms should be shared with the respirologist. If the nocturnal O2 saturations are below 90%, it is time to consider night-time ventilation to stabilize his respiratory status. Breath-stacking and assisted coughing therapies should be continued.
As the condition progresses, daytime oxygen saturation levels – which are typically higher than during the night – may fall below 90%. Oxygen de-saturation indicates the need for daytime or 24 hour ventilator support. Signs and symptoms include: lack of interest in breakfast, daytime sleepiness and fatigue, poor concentration, irritability (especially in the morning), and breathlessness, often on transfers or when eating. Other signs of hypoventilation are failure to thrive, frequent chest infections and even delayed puberty.
In the middle of all of these gradual respiratory changes, there is young man who remains the same social being, with the same interests, desires, and needs as his peers. A 2005 study reported that general and mental health, emotions, social functioning and pain in young men with DMD, who were ventilated, were similar to the population without a chronic illness. They also reported involvement in activities such as wheelchair hockey, attending camps and going on excursions. For them, life had meaning and value.
It is important remember this and to support the social participation of boys with DMD. Laughter is great for their mental and physical health, as the act of laughing requires a burst of effort from their body.
Take a deep breath. Laugh. It’s good for you.
Eric Ferguson is a Physiotherapist at Children’s Developmental Rehabilitation Programme.
Konagaya, M. et al (2005) Effect of positive pressure ventilation on life-span and causes of death in Duchenne Muscular Dystrophy. Poster presentation.
Finsterer, J. Cardiopulmonary support in Duchenne Muscular Dystrophy. Lung (2006) 184: 205-215.
Bach, J. R., Ishakawa, Y., Kim, H. (1997) Prevention of pulmonary morbidity for patients with Duchenne Muscular Dystrophy. Chest 1997; 112:1024-1028.
Ramelli, G.P., Hammer, J. (2005) Swiss physicians’ practices of long-term mechanical ventilatory support of patients with Duchenne Muscular Dystrophy. SWISS MED WKLY; 135: 599-604.