Respiratory
Respiratory weakness can
develop at any stage of disease progression and may cause shortness of
breath, fatigue, impaired quality of life and somnolence. Dyspnoea is caused by
weakened respiratory muscles – intercostals, diaphragm and abdominal muscles.
The diagnosis and management of respiratory
insufficiency is critical because most deaths from ALS are due to respiratory
failure (Miller and others 2009a).
Rafiq and others 2012
Respiratory muscle function significantly predicts
survival and quality of life in patients with MND. The management of
respiratory symptoms and maintenance of lung compliance are particularly
important. NIV prolongs life and maintains quality of life in patients with
MND. NIV requires a specialist service with ability to monitor and detect
hypoventilation, to start NIV with the optimal machine and interface and
optimised settings, to monitor the effectiveness of NIV and to manage complications.
It is essential to have effective communication with the patient and family
throughout the service. It is particularly important that the patient
understands the role of NIV, and that the clinician records their wishes early
on regarding management of intercurrent illness, increasing reliance of NIV and
end-of-life care. The recent NICE guidelines concluded that such a service is a
cost-effective use of NHS resources.
Practice points
§
Domiciliary
NIV therapy has been an important advance for patients with MND.
§
Cough
strength may be impaired in MND; a suitable cough augmentation technique can
help such patients.
§
Clinicians
should pay careful attention to nutritional support in patients with MND.
§
Pharmacological
management of symptoms may include anticholinergics for excess saliva and
mucolytics, for example, carbocisteine, to reduce secretion viscosity.
§
Tracheostomy
ventilation is an option for patients who wish to live but who cannot use NIV.
§
Palliative
care needs, end-of-life issues and stopping respiratory support should be
discussed regularly with the patient and the family
MND Australia 2011
Clinical features
§ early in the course of the disease nocturnal
hypoventilation may not be manifest by obvious shortness of breath but more by
headaches or general tiredness
§ later, more marked shortness of breath may appear but
this tends to be at the time when the person living with MND has severe
generalised weakness which may affect the throat and limb muscles - the
symptoms at that time may include:
§ breathlessness on exertion, sometimes just the
exertion of speaking or eating
§ sleep disturbance, anxiety and panic
§ orthopnoea - breathless lying flat
§ quiet voice and fewer words per breath
§ weakened cough and sneeze
§ hypoventilation is worse during sleep. Upper airway
may also be partially obstructed due to bulbar and laryngeal muscle weakness
§ increasing blood C02 levels result in headaches,
nausea and tiredness, especially on waking
§ hypoxia, especially if there is coexisting lung disease
Management
Regular respiratory assessments, including sleep
studies, by a respiratory physician are indicated in most persons living with
MND.
§ these should be initiated at a relatively early stage
and their timing depends upon the level of abnormality detected
§ where nocturnal hyperventilation is detected it may be
appropriate for the respiratory physician to initiate and prescribe
non-invasive positive pressure ventilation (NIPPV)
没有评论:
发表评论