Chest infections
Prompt use of an antibiotic is recommended if phlegm is discoloured or copious and the individual feels unwell and/or feverish. Flu and colds are often followed by a bacterial infection so that an antibiotic may be required if symptoms don’t clear up. Huffing and chest physiotherapy should be started as soon as possible. If these measures are not beneficial then further medical help should be sought. Children and adults with a tendency to wheeze may be prescribed a bronchodilator drug such as salbutomol (ventolin) which can be delivered by inhaler, spacer device or nebuliser.
A reserve course of antibiotics at home is useful to provide peace of mind and treat infections swiftly.
Ventilation
Breathing can be assisted by artificial ventilation if simpler medical measures fail to maintain carbon dioxide and oxygen levels, for example during a chest infection or for nocturnal hypoventilation. Nearly always breathing can be supported using a non-invasive system. Ventilation via tracheostomy is only required in individuals with severe swallowing problems, or inability to use non-invasive ventilation. A recent study suggests the best time to start non-invasive ventilation is when the child or adult develops symptomatic nocturnal hypoventilation. Without non-invasive ventilation individuals with nocturnal hypoventilation are likely to develop respiratory failure in the day during the next 1-2 years.
Non-invasive ventilation
This system consists of a closely fitting facemask joined to a portable positive pressure ventilator which augments the patient’s breathing, thereby increasing oxygen and reducing carbon dioxide levels. A range of ventilators can be used such as the BiPAP (Respironics), VPAP (ResMed), Breas PV 403, Nippy (B&D Electromedical). Many of these are portable and all are easy to operate. There is also an increasing variety of masks and interfaces. In most individuals ventilation is initially needed only at night. If respiratory muscle weakness progresses then use during the day may be required. Most patients are able to quickly acclimatise to non-invasive ventilation and find that their sleep quality improves.
Noninvasive ventilation can produce excellent control of symptoms in adults and children, sometimes over long periods of time. Evidence suggests that non-invasive ventilation may also reduce the frequency of chest infections and decrease hospital admissions. However, if the swallowing muscles are very weak, non-invasive ventilation cannot prevent aspiration and in this situation another form of ventilation (tracheostomy ventilation) that will protect the airway can be considered. Ventilatory options should always be discussed on an individual basis, taking into full account the wishes of the patient and family, and the clinical circumstances.
Cough assistance
Physiotherapy can be very helpful in assisting cough and clearing secretions. The efficiency of coughing can be assessed by a cough peak flow measurement. Values in teenagers and adults below 270/minute suggest some weakness of cough and if values are less than 160/minute clearance of phlegm can be a major problem.
In individuals who are already using non-invasive ventilation, physiotherapy when resting on the ventilator can improve the effectiveness of a physiotherapy session and make it less tiring for the child or adult.
Use of an ambu bag can help the individual to take bigger breaths. If these measures are insufficient a cough in-exsufflator device may be valuable in adults and children with frequent chest infections and a poor cough. The cough in-exsufflator provides a large breath in (via mask or mouthpiece) and then applies a negative pressure (suction) with expiration so that secretions are sucked away. The cough in-exsufflator can be used in adults and children (even in children below 1 year old) but there is little experience with these in tiny babies. There is good evidence that the combination of non-invasive ventilation and the cough in-exsufflator can reduce the need for tracheostomy ventilation in Duchenne muscular dystrophy. Devices such as the Percussionaire or ‘Vest’ aim to vibrate secretions lose but have not been fully evaluated yet.
Other forms of ventilatory support
‘Continuous positive airway pressure’ (CPAP) is a mask and compressor system which is a form of non-invasive respiratory support but delivers a constant pressure rather than ventilatory assistance. This treatment is helpful in obstructive sleep apnoea as the pressure acts to hold the upper airway open, but is usually not sufficient to deal with nocturnal hypoventilation, or in individuals with respiratory muscle weakness where noninvasive ventilation is almost always preferable.
Negative pressure devices such as the tank ventilator, cuirass, and other devices such as the rocking bed were used in the past to treat breathing problems caused by neuromuscular disorders, but have now been mainly superseded by non-invasive positive pressure ventilation. However, negative pressure ventilation is still available for individuals who do not adapt to mask ventilation, and newer negative pressure models such as the Hayek Oscillator may have a role in very young children and some adults. Ventilation via a mouth-piece is a variant of non-invasive ventilation that can be used at night or as a breathing aid during the day.
There is much that can be done now to control respiratory problems in neuromuscular disorders. Although a decline in respiratory capacity is inevitable in some conditions, symptom control produced by treatment such as non-invasive ventilation has been shown to improve quality of life. Children and adolescents using nocturnal non-invasive ventilation are able to return to school or higher education and adults are able to return to their usual daily activities.
Centres providing respiratory support
There are an increasing number of hospitals which carry out sleep studies and provide respiratory support for patients with neuromuscular disorders. The centres with major interest:
- Royal Brompton Hospital, London
- St.Thomas’ / Guy’s Hospital, London
- Great Ormond Street Hospital
- Hammersmith Hospital, London
- Fazackerley Hospital, Liverpool
- City General Hospital, Stoke
- Glenfield Hospital, Leicester
- Papworth Hospital, Cambridgeshire
- Newcastle General Hospital
- Wythenshawe Hospital, Manchester
- St. James Hospital, Leeds
- Radcliffe Infirmary, Oxford
- Sheffield Hospital
- Hospital for Sick Children, Glasgow
- Queens Medical Centre, Nottingham