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Respiratory Support in Sheffield

This section provides information about respiratory assessment, breathing muscle weakness, Non-Invasive Ventilation (NIV) and assisted cough.

Assessment of Breathing Muscles

At most clinic visits you will be invited to perform one or more simple breathing tests (see SVC, SNIP, PCF) which help us to monitor the strength of your breathing muscles. We will also ask you some questions about your breathing, some of which may not seem directly connected to your breathing;

  • Sleep Quality

  • Appetite

  • Morning Headaches

but changes in these can be the result of a change in the strength of your breathing muscles. Assessing your breathing regularly allows us to detect changes early and thus offer treatment as soon as it might be useful for you.

What treatment options are available?

Non-Invasive Ventilation (NIV)

Weakness of the respiratory muscles can occur just as it does in other muscle groups (limbs, trunk, throat). Whilst we cannot stop this weakness we can offer mechanical support which improves your breathing and quality of life. This support is usually known as NIV.

NIV is a way of helping get a little more air in to your lungs as you breathe to ensure that you fill your lungs every time you breathe in (inhale) and thus are able to breathe out more effectively (exhale). This ensures that you move air in and out of your lungs (ventilate) as efficiently as possible and achieve appropriate levels of oxygen and carbon dioxide in your blood. Improved ventilation should result in an improvement in the symptoms associated with respiratory weakness.

NIV is provided by a small machine which acts like a small compressor, delivering air under some positive pressure to you every time you breathe. The air is delivered via a tube and a mask. The machine is portable (wt 4kg).

Click here to visit our web-based resource myNIV for more information about NIV (non-invasive ventilation)

When would I use the NIV?

Initially we would encourage people to use their NIV when they sleep. Your breathing is normally reduced when you sleep so, if your breathing is less strong, your breathing during sleep will be more affected.  Maintaining effective breathing during sleep with some mechanical support (NIV) helps improve the quality of your sleep, is least intrusive and improves how you feel during the day.

If your respiratory strength continues to decline some people will chose to use the NIV during the day as well as at night time but this varies from person to person. There is no reason why NIV cannot be used for 24 hours a day but not everyone wants to do this and we will support whatever decision you make. Many of the symptoms of breathlessness can be helped with medication and advice.

How will NIV be introduced if I chose to try it?

NIV would be introduced if overnight sleep studies or your symptoms suggested a trial of NIV would be beneficial to you. It can be started in hospital or at home depending on your circumstances, safety and preferences.

If you come into hospital you will be admitted to the Neurology ward where the nursing staff have a lot of experience of helping people start to use NIV and a Respiratory Physiologist who will explain how the machine works and then try masks and settings with you. You will try the NIV overnight, usually for 1-2 nights before taking it home to continue using the system. The Respiratory Physiologist will see you in hospital whilst you are using it there and then at home. Once established on NIV the Respiratory Physiologist will visit you at home regularly and see you in the Outpatient clinic whenever you attend. A telephone and email helpline is available for use at any time.

If you are set up at home the Respiratory Physiologist will do exactly the same, introducing the machine, masks and setting s to you at home and then follow you up in the same way.

Is it difficult to use and look after the NIV system?

Using the NIV machine is very simple once the Respiratory Physiologist has established the appropriate settings for you. Usually all you, or a carer, have to do is switch the machine on and off and be able to put the mask on and take it off. The settings on the machine are locked so that you cannot alter them by mistake, something a lot of people worry about.

Sometimes it is difficult for people to put a mask on and remove it by themselves if their hand and/or arm function is reduced. This is taken into consideration before we decide to introduce NIV and we have a number of masks to try to find the most appropriate one for you.

When would the best time to start using NIV be?

This varies from person to person as we try to tailor treatment to the individual.

Experience and evidence from published research suggests that the best time to introduce NIV is when people are experiencing the symptoms associated with weakening breathing muscles and have measurable changes in the strength of their breathing muscles. This is why we test your breathing regularly and ask you questions about your breathing.

Sometimes, however, our tests may show a change in your breathing but you are unaware of any symptoms. Initially using NIV is not easy so it is understandable that the people who may do best initially are those who perceive a significant improvement in their symptoms following the introduction of NIV. However many people are not aware of how much their sleep quality, for example, has been affected and we would encourage people with objective measures of respiratory weakness to try NIV and see if they detect an improvement in how they feel during the day. Many are pleasantly surprised.

The decision to use NIV remains that of the person with MND. If they really struggle initially we will always offer respiratory support again at a later date.  We also understand that using NIV takes time so we have no minimum hours of use requirement. We will support everyone using NIV with the objective of enabling them to get the most out of the available ventilatory support as they can manage.

What are the benefits of NIV?

Research has shown that people with MND and weak breathing muscles who use NIV regularly have an improvement in survival and quality of life.

Secretion Management

Many people with MND find that coughing and clearing thick secretions from their chest becomes difficult if their respiratory muscles get weaker. If this is becoming a problem for you we can advise on how best to help thin these secretions to make it easier for you (of which there are a number of management options some which are mentioned below):

  • ensuring you drink plenty to keep well hydrated

  • trying pineapple or other exotic fruit juice (they contain an enzyme which helps thin secretions)

  • trying a medication which thins mucous (Mucodyne)

We can also advise about the use of devices (breath stacking, mechanical insufflators-exsufflators) which help stimulate or simulate a cough and, if appropriate, supply the equipment and train you to use it.

Management of other problems with secretions should be discussed with the team who can advise you in relation to your particular problem.


SVC (Slow Vital Capacity): a measure of how much air you can get in to your lungs. You will be asked to take a big breath in and then to blow it all out steadily into a machine via a mask. You will be asked to repeat the test 3 times but with a short rest in between each blow.

SNIP (Sniff Nasal Inspiratory Pressure): a way of measuring how strong your inspiratory (Breathing in muscles) muscles  are. A small probe will be placed in one of your nostrils and you will be asked to sniff hard. Again this test will be repeated 5-10 times but you will have a rest in between each sniff.

PCF (Peak Cough Flow): a measure of how effective your cough is. You will be asked to take a big breath in and then cough as hard as you can into a peak flow meter via a mask. This test will be repeated 3 times with a rest in between each test.


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