Initiation of NIV
Oropharyngeal and respiratory secretions are a major barrier to effective NIV tolerance and ventilation. This section discusses the optimisation of cough and respiratory secretions.
The importance of poor cough in MND
Excessive respiratory secretions occur in MND as a patient’s cough deteriorates due to respiratory muscle weakness and poor bulbar function. Inspiratory and expiratory muscle weakness causes reduced lung volumes and bulbar dysfunction results in poor cough, lung atelectasis and failure to clear respiratory secretions.
Poor bulbar function also causes aspiration of oropharyngeal secretions, food and fluids as well as poor oral hygiene. These problems can be a major barrier to NIV use resulting in ineffective ventilation as well as pneumonia and distressing symptoms due to pooling of secretions in the lungs.
It is important to address both respiratory and oropharyngeal secretions together as both contribute to respiratory secretions. In addition, the treatment of oropharyngeal secretions to dry up the mouth with anticholinergic medication (eg hyoscine, glycopyrollate) can thicken respiratory secretions.
In the following video, Rosie Whitehead, a Respiratory Physiotherapist, explains how she approaches poor cough and excessive secretions, including describing what Cough Assist is.
How to manage bulbar weakness and excessive secretions
“Some patients, if they are struggling with their secretions or they have bulbar management problems, we might discuss with their neurologist about medications to help clear their chest. Or we might discuss with the respiratory team about a cough assist machine because if they are not clearing their secretions they won’t be able to ventilate effectively.
A cough assist machine is a machine than can give you a big breath in, then it helps you clear your secretions so it gives you a negative pressure to cough out. So when your respiratory muscles get weaker the idea is that it can do the effort of you taking a big breath in and then the clearing of, coughing out. So the idea is that it clears your chest more effectively and gets rid of your secretions so hopefully you can ventilate better with your NIV.
Generally we would give a Cough Assist to anyone who aren’t able to clear their secretions as well or might have a cough that is borderline weak or they feel like they are not able to clear their chest effectively or they are having recurrent chest infections.”
Conservative management of poor cough
On all patients, conservative measures should be considered.
Review of any treatments that may dry the respiratory tract such as those used to treat excessive saliva
Nutrition eg trial of dairy free diet
Mouth care (there is some weak evidence that oral hygiene measures can reduce the incidence of aspiration pneumonia)
Treatment of any infection
Assessment for other causes of cough such as gastro-oesophageal reflux
Medical management of poor cough
Medications that can dry out respiratory secretions, in particular those used to treat excessive saliva/oropharngeal secretions should be reviewed. Adjustments in medication may be needed to gain a balance between reducing saliva and avoiding a dry mouth and thickened respiratory secretions.
Mucolytics: carbocysteine capsules/liquid 375mg three times daily up to 750mg three times daily is well tolerated.
Nebulised saline may be helpful in those with excessive respiratory secretions.
There is no strong evidence for the use of hypertonic saline at present.
Other measures that should be considered in people with poor cough:
Humidification of the NIV machine should be considered for patients who are experiencing mucosal dryness or thick secretions.
An oropharygneal suction machine should be offered to aid expectoration and mouth care.
Chest clearing techniques such has huffing or postural drainage may be helpful but can be fatiguing for patients.
Cough assist machine
Mechanical cough assist
Mechanical cough assist can be particularly helpful for people with:
Difficulty clearing secretions
Recurrent chest infections
A peak cough flow < 160l/m
In the following video, Katie Flowers, a Respiratory Physiotherapist, explains to people living with motor neurone disease what options there are for keeping their chest clear.
Good practice points
Treatment of oropharyngeal secretions may worsen respiratory secretions.
Conservative measures can be offered to all patients.
A cough assist is particularly useful for people with a peak cough flow <160l/m or those who have difficulty clearing secretions.
Oral suction and nebulised saline should also be considered.
For more information relating to secretion management and cough optimisation, go to our Resources page or see the following guidance and information sheets:
Healthcare professional pathway: