VOLUME VERSUS PRESSURE TARGETED NON-INVASIVE VENTILATION IN AMYOTROPHIC LATERAL SCLEROSIS (VOP ALS): study protocol for a randomised controlled trial (preprint)

Introduction Amyotrophic lateral sclerosis (ALS) is a rare, idiopathic, progressive, neuromuscular disease. The prevalence in England and Wales is between 4 and 5 cases per 100,000. A significant proportion of ALS cases are complicated by respiratory and sleep impairment which can reduce health related quality of life (HRQOL) and survival. Non-invasive ventilation (NIV) is the standard of care to treat respiratory and sleep symptoms. Patients who are compliant with NIV have improved survival, HRQOL and reduced symptoms. Different modes of NIV are available and broadly fall into two categories: pressure support ventilation (PSV) and volume assured pressure support (VAPS) ventilation. A clinically enhanced version of VAPS in the form of intelligent volume assured pressure support with automatic EPAP (iVAPS-AE) is now widely available and although spontaneous timed (ST) mode is the preferred choice in ALS, to date no one mode has been shown to be superior. In this single-centre randomised controlled trial we will explore the differences in NIV compliance and effect on HRQOL, between ST and iVAPS-AE NIV modes in patients diagnosed with respiratory failure due to ALS. We also want to explore the optimal NIV mode for patients diagnosed with ALS. This trial is still in the data collection phase and has the potential to guide changes in clinical respiratory practice in ALS. Methods and Analysis VOP ALS is a single blinded, single centre, RCT exploring the impact of iVAPS-AE on patient outcomes compared to ST-mode in patients diagnosed with ALS related respiratory impairment. Primary outcome is mean NIV compliance and secondary outcome is health reported quality of life, both measured over 90 days. The study aimed to recruit 40 patients, but it was revised to 15 because of the COVID-19 pandemic. The analysis will be mainly descriptive by treatment arms and summarised with 95% confidence interval. Ethics and Dissemination VOP ALS is sponsored in the UK by University Hospitals Coventry and Warwickshire NHS Trust and has been granted ethical approval by Northwest - Haydock Research Ethics Committee Ethics Committee (REC ref: 21/NW/0326). Publication of results in a peer-reviewed journal and conference presentations are expected. Trial Registration Number: NCT05328492. Registered 4th April 2022 - Retrospectively registered, https://clinicaltrials.gov/study/NCT05328492

Utility of Cardiopulmonary Exercise Testing (CPET) in the Post-COVID-19 Context: Retrospective Analysis of a Single Centre Experience. (preprint)

Cardiopulmonary exercise testing (CPET) allows objective assessment of a patient’s global response to maximal incremental exercise. CPET has been proposed to have a role in investigating post-COVID syndrome. However, CPET is resource intensive, and essential for restoration of other clinical services (e.g. cancer surgery). The aim of this study was to explore utility of CPET in assessing functional status of COVID-19 survivors with persistent dyspnoea. Of the 600 patients reviewed in a post-COVID-19 assessment clinic between May 2020 and April 2021, 12 (male/female: 8/4; age: 4±15.2 years; BMI: 32.8±5.9 kg/m2; non-smokers/ smokers: 8/4) were referred for CPET due to persistent breathlessness out-keeping with disease severity. Of these patients, 10 patients demonstrated reduced peak VO2, whilst five had an exercise limitation attributed to physical deconditioning. Two patients had mainly a cardiac limitation to exercise, with a further three patients demonstrating breathing pattern disorder, pulmonary vascular disease and lung disease.  The findings of this single-centre study suggest that intensive CPET testing may not add substantial additional clinical information to aid patient investigation/management in the context of post-COVID. Such resource intensive procedures may be better utilised in selected patients and in the restoration of NHS services following the COVID-19 pandemic.