Information for Patients
The RSSC provides specialist treatments to patients with respiratory failure due to a wide range of conditions. Treatments include home ventilation, specialist oxygen provision, the Motor Neurone Disease Service, and the Progressive Care Programme.
What is respiratory failure?
The principal function of the respiratory system is to get oxygen into the body and to release carbon dioxide. To achieve this, the respiratory system requires a gas-exchanging organ (the lungs), an effective pump to move the air (the breathing muscles such as the diaphragm), and effective control of the required depth and rate of breathing (the brain). Abnormalities in the function of any of these essential components can result in respiratory failure.
Respiratory failure occurs when the respiratory system fails to provide the body with adequate amounts of oxygen and / or fails to eliminate carbon dioxide.
What are the symptoms of respiratory failure?
In addition to the specific symptoms of the underlying condition which has caused respiratory failure, patients with respiratory failure may develop symptoms due to the reduced oxygen and increased carbon dioxide levels.
- A lack of oxygen (hypoxia) causes restlessness, confusion, agitation and breathlessness.
- An excess of carbon dioxide causes headaches, drowsiness and confusion.
- Respiratory failure can be acute (developing rapidly) or chronic (developing slowly).
- In chronic respiratory failure, the body may be able to adapt to slightly lower levels of oxygen and higher levels of carbon dioxide in the bloodstream. However, this can sometimes cause additional strain upon other organs. For example, a persistently reduced level of oxygen can cause damage to the heart, resulting in fluid retention.
How is respiratory failure diagnosed?
Respiratory failure can usually be confirmed by taking an 'arterial blood gas sample', in other words a sample of blood from an artery rather than from a vein. This provides accurate information about the capacity of the respiratory system to exchange oxygen and carbon dioxide. This sample is usually obtained from the wrist, but is otherwise similar to a standard blood test from a vein.
If a more comprehensive assessment is required, patients may be admitted to the RSSC for a short stay to undertake an overnight sleep study and further investigations such as lung function studies.
How can respiratory failure be treated?
There are two types of respiratory failure and they are treated in different ways.
Type 1 respiratory failure is a lack of oxygen alone. It may be caused by any long-term condition causing damage to the lungs (for example Chronic Obstructive Pulmonary Disease or bronchiectasis). If the problem is simply a lack of oxygen, then treatment with oxygen alone may be sufficient.
Type 2 respiratory failure is a lack of oxygen plus an excess of carbon dioxide. This build up of carbon dioxide is due to the fact that the respiratory system has been unable to clear it sufficiently from the body. This may be because the breathing has become too shallow during sleep and is the reason why some people wake up with a headache. In such circumstances, carbon dioxide can only be removed effectively by helping the patient to take deeper breaths. This is achieved by using non-invasive ventilation.
What is non-invasive ventilation?
Non-invasive ventilation (NIV) blows air into the lungs, via a nasal mask or a face mask, to ensure that the breathing remains supported and to prevent under-breathing. The NIV machine will recognise that the person using it has started to breathe in and assists with each breath. 'Non-invasive' simply means that this process is achieved via an external mask, rather than anything within the body (such as a tracheostomy tube). The overnight use of NIV will usually be sufficient to improve the symptoms of respiratory failure, although some patients may require ventilation in the day as well.
Who might benefit from home NIV?
All patients are assessed for their suitability for treatment. The RSSC currently cares for over 1300 patients on ventilatory support in their own homes.
Conditions which may benefit from home ventilation include chest wall disorders (such as scoliosis, thoracoplasty and obesity-hypoventilation syndrome), neuromuscular disorders (such as muscular dystrophies, myotonic dystrophy, motor neurone disease and diaphragmatic dysfunction), neurological disorders (such as spinal cord injuries and central alveolar hypoventilation), and pulmonary diseases (such as Chronic Obstructive Pulmonary Disease (COPD), bronchiectasis and cystic fibrosis).
What are the benefits of home NIV?
The aims of home NIV are to reduce respiratory symptoms and improve quality of life. In most circumstances, home NIV is only required during sleep. Sleep quality is improved and daytime symptoms such as tiredness and fatigue may be greatly reduced. By controlling the respiratory failure, it is hoped that treatment will slow down or prevent any further deterioration.
How is home NIV started?
Patients referred for consideration of home NIV will usually be admitted to the RSSC for assessment. A series of investigations are carried out, including an overnight sleep study. If home NIV is indicated, it will usually be started during the same admission. This process often takes a few further nights, partly due to getting used to using the NIV mask, and partly because we need to ensure that the most appropriate settings have been selected for ongoing use at home. All of the equipment for continued use at home is provided by the RSSC.
After discharge, it is important to continue to use NIV every night. Ongoing follow-up, servicing of machines and the replacement of equipment are all provided by the RSSC. An overnight stay is usually planned to take place 6 weeks after starting home ventilation. Thereafter, follow-up can take place as required and may only need to be as infrequent as once each year.