Respiratory muscle weakness affects most people with MND. It is important for you to be aware of how to minimise the effects of this symptom.
As MND progresses the muscles between the ribs and the diaphragm weaken, leading to respiratory problems.
Some signs of respiratory problems are:
- increased use of muscles of the neck and shoulder (accessory muscles) to help with breathing
- increased respiratory rate
- shallow breathing
- weak cough
- weak sniff.
As breathing difficulty increases, less air is drawn into the lungs. This may lower the amount of oxygen that can be absorbed into the blood. It also becomes difficult for the person to exhale, which can result in a build-up carbon dioxide. Reduced breathing capacity can lead to:
- daytime sleepiness
- breathlessness (dyspnoea) even when at rest
- breathlessness lying flat (orthopnoea)
- non refreshing or disturbed sleep
- morning headaches
- poor speech volume
- decreased appetite
- impaired concentration and/or memory
- a weak cough may mean the person living with MND is less able to clear their throat
- there may be an increase in chest infections.
Use of oxygen with MND
Respiratory muscle weakness leads to the retention of carbon dioxide (hypercapnia). In this situation the use of oxygen can lead to further respiratory depression. Oxygen should only be used under guidance of the person’s specialist team.
Support you can give
Breathlessness can be distressing, but there are things that you can do to make the person more comfortable. These tips can help to ease breathing:
- position is important. Sitting in a slumped position restricts lung capacity. Sitting up or slightly reclined may be better than lying down
- when sitting, the person should make sure their bottom is well back in the chair, their back straight and well supported
- if excessive saliva or mucus is a problem, seek the advice of the GP, as medication may be appropriate, and speech therapist about controlling it. A physiotherapist can also teach assisted cough techniques
- try to keep bedroom and living areas well ventilated and at a comfortable, steady temperature (around 18 and 21 degrees respectively)
- anxiety experienced with shortness of breath may be helped by breathing in a calm and purposeful way until the sensation has passed
- routine chest physiotherapy can be beneficial, but should not be too vigorous. A respiratory physiotherapist may also be able to suggest a programme of breathing exercises to help maintain lung expansion and muscle elasticity
- medication can be prescribed to relieve feelings of breathlessness
- if shortness of breath cannot be managed, the GP or neurologist should be consulted immediately where other options such as non-invasive ventilation may be discussed.
Long Term Solution
Adequate information and advice is needed so that treatment options can be discussed and decisions can be made well in advance. This is necessary to avoid possible unplanned or unwanted interventions.
In this technique the person is taught to take 3 breaths in without exhaling, expanding the lungs with more air and then exhaling all at once. It can also be supported using a Lung Volume Recruitment (LVR) bag which adds additional air to that already in the lungs. There is also a helpful technique called a manually assisted cough. A physiotherapist needs to provide instruction on how to do this.
Mechanical Insufflator/Exsufflator (MI:E) devices
These are often referred to as CoughAssist machines and can sometimes be useful. These devices support the ability of the inspiratory and expiratory muscles, which may improve a person’s cough, aiding secretion clearance. Use of MI:E has been shown to reduce the incidence of chest infections. A respiratory specialist will advise suitability and if appropriate prescribe the treatment regime needed. Training should also be provided to the person with MND and any family/carers who may operate the device.
Non-invasive ventilation (NIV)
If the symptoms related to increasing respiratory muscle weakness impact on quality of life, and the therapy is suitable, some people may choose to use NIV. NIV has been shown to improve quality of life for people living with MND but it may not be suitable for everyone. A trial of NIV can be offered if the person is symptomatic and/or the results of respiratory function tests indicate they are likely to benefit from the treatment. A comprehensive care plan should be prepared in consultation with the person living with MND and their carers and family as appropriate before NIV is started.
This should cover:
- long-term support offered
- arrangements in place for device maintenance
- 24-hour emergency clinical and technical support.
NIV is delivered via a mask usually at night initially and then as required during the day as MND progresses. If you are caring for someone with MND using NIV you might find the myNiv resource useful as it explains the treatment very clearly.
Very occasionally, a person with MND may be fully ventilated via a tracheostomy. This type of ventilation would need very careful organisation and anticipatory planning as it is often very difficult to support a person in their own home who requires this level of ventilation.
Withdrawing assisted ventilation
Assisted ventilation, either invasive via a tracheostomy or non-invasively, is considered to be treatment. A person retains a legal right to refuse all treatment at any point in their care if they so wish, therefore, there may come a time that they chose to discontinue the ventilation they have been receiving. Whilst this is a complex and difficult decision for the person to make it can be equally challenging and indeed distressing for family members and professionals caring for them. The involvement of the local palliative care service can be crucial in supporting the person and the professionals at this time. Detailed guidance on withdrawal of assisted ventilation is available.
Coughing and choking
For some people with MND the chest muscles can become weaker and this can lead to being unable to cough effectively. If this happens the person may find it more difficult to clear their throat and this could lead to more frequent coughing. Difficulty coughing and clearing the throat can put some people with MND at a greater risk of a chest infection.
A referral to local physiotherapist for an assessment of the breathing muscles and to learn breathing techniques can help the person cough more forcibly. One such technique is called breath stacking, whereby the person is taught to take 3 breaths in without exhaling, therefore expanding the lungs with more air and then exhaling all at once. A step on from this is assisted breath stacking using a lung volume recruitment bag. Moving more air though the throat will help eject foreign bodies / sputum that may have been causing the irritation.
Some people with MND find it useful to use a machine called a mechanical insufflation-exsufflation machine, sometimes known by the brand name CoughAssist. It clears secretions by applying a positive pressure to the airway, followed by negative pressure. This rapid shift simulates a natural cough and can help to reduce the risk of recurrent respiratory infections.
A small number of people with MND may occasionally experience unexpected coughing or choking episodes brought on by spasm in stiff throat muscles. This can be frightening when it happens but it will pass. It is important to note that there is no evidence that people with MND die from choking or coughing and making sure that the person with MND and their carers know this reduces unnecessary anxiety. If coughing or choking occurs, sit the person down, open the window or doors to get a breeze going past the person or use a fan to achieve this. Help the person sit forward slightly so that any secretions in the mouth can drain out. Remain calm and reassure that this will pass in a few minutes.
Understandably, struggling to cough and choking episodes can be very frightening and cause increased anxiety. Anxiety further affects breathing and makes the air ways a little tighter increasing the work of breathing. It may be worth exploring the use of an appropriate anti-anxiety medication such as Lorazepam with the person’s GP which can will help to keep the person with MND calm during severe choking episodes.
MND Just in Case Kit
The MND Association Just in Case Kit is a great resource designed to hold medication for the relief of anxiety and breathlessness. Having it to hand means people with MND and carers can see that fears have been addressed. For the GP and district or community nurse it provides guidance on symptom management and storage for the prescribed medications. Once the need for a kit has been discussed and agreed with the person with MND and their carer:
- the GP orders a kit from MND Connect telephone number 0808 802 6262 for a named person with MND. The kit is supplied free of charge.
- the GP and district or community nurse agree on a plan to advise and support the carer in the use of the kit.
- the GP prescribes medication to be supplied with the kit.
- the GP, or community or district nurse, gives the kit to the person with MND and ensures the carer knows how it can be used.