Dysfunctional breathing

 

The interaction between respiratory illness and psychological issues is well known. This is particularly true with chronic (long term) diseases such as asthma, where psychosocial factors can adversely affect the child’s clinical state, and ultimately their prognosis. There are also a number of respiratory conditions where the underlying cause is psychogenic. These functional disorders often coexist with an underlying problem such as asthma, which can make their diagnosis and management more difficult.

Dysfunctional breathing has been defined as a chronic or recurrent change in the person’s breathing pattern, which causes respiratory and sometimes non-respiratory symptoms. How common this is in children is unknown. It is important to make the correct diagnosis, which is often one of exclusion, a careful history is the key and allowing enough time is important. The children have usually seen many doctors before seeing an experienced specialist who is familiar with the relevant condition. The parents are often extremely worried, and sometimes (but not always) the child is as well, especially with chest pain. Usually the symptoms are managed quite easily with explanation and reassurance. Misdiagnosis is common and the children are often on inappropriate medications, including oral steroids, and these must be stopped. Sometimes physiotherapists are needed (for breathing training and relaxation therapy), especially with types of dysfunctional breathing. In more severe cases, input from a psychologist may be required.

 

Habit cough

The history of the cough is fairly typical. It usually starts with an acute respiratory illness, often just a simple cold. The child gets better but the cough remains. It can go on for months and does not respond to therapy, by the time the child sees the specialist they have often been on multiple courses of antibiotics, inhalers and even oral steroids (prednisolone). It is an extremely loud hollow explosive short cough that disturbs the family, classmates and teachers, although the child is usually unconcerned. It can be extremely frequent, even several times a minute. The key though is that as soon as the child falls asleep, it is like turning off a switch and the cough stops; in the history though it is important to be sure any reported night cough is not simply the child lying awake in bed or getting up to go to the toilet. The child is otherwise completely well, with a normal examination, and can demonstrate the cough when asked. Lung function is also normal unless the child coughs during spirometry. Further tests are unnecessary although a normal chest x-ray may be reassuring. Reassurance (and ignoring the cough) is usually all that is necessary but it is critical the child and parents believe and trust the doctor explaining the diagnosis. It helps to describe it as a form of tic, and also to emphasise it is not a deliberate provocative act by the child to annoy their parents. Occasionally the child needs help from a physiotherapist to learn how to control the cough using relaxation techniques. There may be particular stresses in the child’s life and possibly secondary gain, but these are not always obvious; there may also be school phobia/avoidance or attention-seeking. It is rare though for a psychologist to be needed.

 

Vocal cord dysfunction (VCD)

This is characterised by an inappropriate coming together of the vocal cords when the child breathes in. The glottis is the part of the larynx consisting of the vocal cords and the slit like opening between them. Normally, the glottis widens slightly during quiet inspiration* as the cords move apart, but then narrows during expiration*. VCD can lead to breathlessness, cough, wheeze (both inspiratory and expiratory) or stridor (a harsh noise on breathing in), chest tightness and discomfort. During acute episodes the child may have respiratory distress, and both inspiratory and expiratory wheeze may be heard. In some it occurs suddenly with no provoking factor, and in others exercise may set off the symptoms. Classically described in young adult women, it is certainly seen in children – both boys and girls. There are often significant stresses in the child’s life. Examination (when symptom-free) is usually normal, and lung function testing may reveal characteristic signs or be normal. To confuse the picture, these children often have accompanying asthma, but due to the VCD the asthma is thought to be severe, which is not usually the case. In many cases though the symptoms are all due to VCD but asthma has been misdiagnosed. There may also be an association with gastro-oesophageal reflux, or a postnasal drip. The symptoms attributable to VCD do not respond to asthma therapy. The diagnosis can be confirmed by direct laryngoscopy observing the vocal cords while the child is awake, and asked to make various sounds, or exercise on a bike during the procedure. This is quite invasive and many children will not tolerate laryngoscopy while awake so we rarely perform this. Management starts with reassurance but usually involves a multidisciplinary approach including a physiotherapist, speech and language therapist and a psychologist.

 

Hyperventilation syndrome

This is a state of over-breathing which leads to an acute fall in blood carbon dioxide levels. Although people can deliberately hyperventilate, this is not usually what happens. The children may complain that they can’t catch their breath or realise they are breathing too quickly.  It leads to chest pain, breathlessness, dizziness, palpitations, fast heart rate, tremors and sweating. There may also be numbness or tingling in the hands. Symptoms can last for minutes or hours. As with VCD it is more common in young adult women, but can happen in adolescent girls and less often boys. Underlying stresses or anxiety are not uncommon. The child may have asthma s well, and the anxiety caused by the onset of an acute asthma episode may provoke hyperventilation, which then worsens the asthma, and leads to diagnostic confusion. Although the acute symptoms can be alleviated with a rebreathing bag (to increase the carbon dioxide levels), reassurance and education are the key to long term improvement. Unfortunately prognosis is not as good as with most of the functional disorders, and it has been reported that up to 40% of patients have symptoms persisting into adulthood, although for most it is relatively benign.

 

Sighing dyspnoea

A sigh consists of a slow deep inspiration followed by a slow expiration; it is usually audible and may be accompanied by obvious movement of the chest, shoulders and head. It is a physiological response to a period of shallow breathing and expands the lungs to full capacity to prevent the lungs’ air sacs collapsing. Many people will sigh when tired or emotional. In sighing dyspnoea*, the child feels the need to repeatedly take a deep breath and feels they cannot get enough air in with normal breathing. The inspiration can be quite exaggerated and is often staccato or shuddering in nature, rather than a smooth movement. The overall respiratory rate remains the same however. There are usually no other symptoms and the child is well. Examination and lung function is normal, and the child can usually demonstrate the symptom when asked, and will often do it more often when it is being discussed in clinic. Explanation and reassurance is all that is usually required, but occasionally physiotherapy for breathing training is needed.

 

Other forms of dysfunctional breathing

Another unusual form of dysfunctional breathing is seen in children who seem to take shallow breaths only. It may be noticed when listening to the chest with a stethoscope and hearing only quiet breath sounds. After some encouragement the child is able to take a bigger breath in and out. Lung function testing may be worse than expected due to poor effort. The child often has underlying asthma, but may present with any number of symptoms including chest pain and breathlessness. Physiotherapy breathing training is usually successful, and attention to posture also helps as the children often sit hunched over.

 

Throat clearing

Repetitive throat clearing is another form of respiratory tic that can be differentiated from an actual cough, although it shares many similar features to a habit cough. Examination is normal and investigations are unnecessary. It is important to ensure symptoms are not associated with gastro-oesophageal reflux or a postnasal drip. Reassurance is usually all that is necessary.

 

 

Pointers in making the diagnosis of a functional respiratory disorder

•  Symptoms disappear when asleep.
•  Often occur suddenly without an obvious trigger, including at rest.
•  Acute episode usually improves quickly and spontaneously, but can be variable duration
•  Ability to speak during the period of acute symptoms.
•  Child usually otherwise well (but may accompany underlying asthma).
•  Child often unconcerned (especially compared to parents and teachers).
•  Normal physical examination.
•  Normal investigations.
•  No response to cough medicines or anti-asthma therapy.

 

* Glossary

Inspiration = breathing in
Expiration = breathing out (exhaling)
Dyspnoea = an uncomfortable sensation of breathing