This pilot randomised single-blind trial evaluated whether adding high-frequency chest wall oscillation (HFCWO) via chest vest (ComfortCough II) to mechanical cough assist improves respiratory outcomes and reduces respiratory infections and hospital admissions compared to mechanical cough assist alone in patients with amyotrophic lateral sclerosis (ALS) receiving non-invasive ventilation.

Patients with amyotrophic lateral sclerosis (ALS) receiving non-invasive ventilation (NIV) at the Multidisciplinary ALS Unit of Hospital Universitario Virgen Macarena (Seville, Spain) were randomised to two parallel groups. The experimental group received high-frequency chest wall oscillation (HFCWO) via chest vest (ComfortCough II/CC20) combined with mechanical cough assist, while the control group received mechanical cough assist alone. The intervention period lasted 3 months, followed by 3 months of follow-up. Primary outcomes included respiratory infections and hospital admissions. Secondary outcomes included respiratory function, quality of life, sleep quality, and secretion clearance capacity. The study was approved by the Ethics Committee of Hospital Universitario Virgen Macarena - Virgen del Rocío (code 2020-01) and sponsored by FISEVI (Fundación Pública Andaluza para la Investigación Biosanitaria de Andalucía).

Inclusion Criteria:

1. Confirmed diagnosis of ALS according to the Revised El Escorial criteria
2. Under follow-up at the Multidisciplinary ALS Unit of Hospital Universitario Virgen Macarena
3. Age between 18 and 90 years
4. Peak cough flow less than 270 L/min or forced vital capacity (FVC) less than 80% of predicted
5. Ability to travel to the Neurolab centre

exclusion criteria:

1. Need for invasive mechanical ventilation
2. Total dependence on non-invasive ventilation (NIV)
3. Severe bulbar involvement
4. Cognitive impairment
5. Comorbidities incompatible with the intervention: pregnancy, rib fractures, known risk of pneumothorax or pneumomediastinum, cerebrospinal fluid fistula, pneumocephalus, or recent barotrauma

Investigators assessing outcomes were blinded to treatment allocation. Blinding of participants and care providers was not feasible due to the nature of the intervention.