Managing respiratory failure in motor neurone disease

Respiratory failure with hypoxaemia or hypercapnia is the most common cause of death in patients with motor neurone disease. It is caused by respiratory muscle weakness.

Enquire about respiratory symptoms early to detect respiratory muscle weakness. Symptoms of respiratory decline in motor neurone disease differ to those seen in patients with chronic advanced respiratory disease. Symptoms and sequelae that can indicate respiratory decline include morning headache, unrefreshing sleep, fatigue, daytime sleepiness, weak cough, dysphagia, breathlessness, excess secretions, poor concentration and memory, and orthopnoea.

Refer to a specialist respiratory service for further evaluation and management if not already provided through a managing multidisciplinary clinic. Respiratory investigations such as forced vital capacity (FVC) and arterial blood gases are useful indicators to assess and monitor respiratory function.

Long-term noninvasive ventilation (usually bilevel positive airway pressure [BPAP]) improve quality of life and support patients with motor neurone disease to live longer. Patients often become dependent on ventilation and are unable to verbally communicate. Plan for ventilatory support withdrawal with the patient, their family and carers, and in consultation with emergency, palliative care, respiratory or intensive care specialist to ensure appropriate protocols are followed and distress is minimised.

Patients may request for withdrawal to occur at a specific time (eg after attainment of a goal or event) or when their condition changes, especially if respiratory function is deteriorating despite optimal therapy. See also Decisions about withdrawing or withholding treatment in palliative care.

For other aspects of breathlessness management, see Breathlessness in palliative care.