Volume Mode Non-invasive Ventilation in Amyotrophic Lateral Sclerosis

The purpose of this study is to assess the efficacy of using intelligent volume assured pressure support (iVAPS-AE) versus spontaneous timed (ST) modes of non-invasive ventilation (NIV) in patients diagnosed with amyotrophic lateral sclerosis (ALS).

The investigators believe that the use of iVAPS-AE mode NIV over a 90 day period will produce NIV compliance data and health-related quality of life (HRQOL) scores that are equivalent or no worse compared to ST mode NIV.

Amyotrophic lateral sclerosis (ALS) is one of five motor neurone diseases (MNDs). It is a rare, incurable disease characterised by progressive destruction of nerve cells called motor neurones that instruct a patient's muscles to contract, to enable all movements, including walking, talking, speaking and swallowing.

Over time as more motor neurone cells are damaged, the muscles used to breathe will weaken and patients will develop breathlessness and sleep disturbances. This can be very distressing and reduce a patient's health- related quality of life (HRQOL). Eventually the condition may progress to the extent that the patient will develop respiratory failure, which is the leading cause of death in ALS.

Respiratory failure is the most frequent cause of death in ALS and as such a significant proportion of ALS cases are complicated by respiratory and bulbar symptoms which can reduce HRQOL from breathlessness, impaired cough and sleep, and can also shorten life expectancy. The use of respiratory support, provided via non-invasive ventilation (NIV), has been shown to be beneficial.

NIV is a safe treatment in ALS and as such current National Institute for Health and Care Excellence (NICE) guidelines recommend a trial of NIV in those ALS patients who develop respiratory impairment

NIV compliance is of significant importance in ALS as it is directly linked to improved survival and health related quality of life. Compliance is affected by various factors including non-invasive ventilation mode, disease type (bulbar vs limb) and baseline physiology.

Various NIV modes exist including pressure support (ST mode) and volume assured pressure support (iVAPS-AE). Evidence suggests that not one mode is more superior, but both have advantages and disadvantages in clinical practice.

This study will follow a standard care pathway and aim to recruit 40 ALS patients randomised to receive ST mode or iVAPS-AE mode. Each patient will enrol onto the study for 90 days and attend 5 hospital visits. The study will assess if iVAPS-AE improves a patient's symptoms sooner and allows a patient to use the NIV for longer periods thereby improving HRQOL.

Eligibility Criteria:
Inclusion Criteria:

Patients with respiratory failure secondary to ALS (diagnosed either at an MND MDT or specialist neurology clinic) according to criteria set out in the NICE guideline (NG42) (2016); Motor neurone disease: assessment and management.

* Patients able to provide informed consent to take part in the research study.
* Patients not contraindicated to commence NIV in accordance with local protocol.
* Patients not currently enrolled in another research study that could alter disease progression.

Exclusion Criteria:

* Acutely unwell or medically complicated patients as assessed by lead investigator. These patients will be urgently reviewed by a dedicated Consultant Physician. The Principal Investigator will be immediately informed.
* An inability to provide informed consent.
* An inability to use NIV.
* Patients whom are contraindicated to commence NIV in accordance with local protocol.