Use of High‐Flow Nasal Cannula in Amyotrophic Lateral Sclerosis Patients Intolerant to Non‐Invasive Ventilation: A Case Series

ABSTRACT Non‐invasive ventilation (NIV) is standard respiratory support for amyotrophic lateral sclerosis (ALS), but intolerance may limit its use. High‐flow nasal cannula (HFNC) has emerged as a potential alternative in selected patients, but evidence regarding its use remains scarce. We describe 18 ALS patients' management with HFNC between 2014 and 2024 after documented intolerance to NIV. Mean age at HFNC initiation was 65.1 ± 12.5 years, and 66.7% of patients were female. Partial NIV intolerance occurred in 38.9% of cases, while 33.3% tolerated intermittent combined NIV and HFNC. During follow‐up, 50.0% of patients required hospitalization, 33.3% experienced respiratory infections, and 27.8% died. Arterial blood gas parameters remained stable, including PaCO 2 ( p = 0.314). Functional status declined significantly, with Barthel Index decreasing (35.0 ± 20.5 vs. 11.7 ± 11.3; p < 0.001), whereas respiratory muscle strength remained unchanged. HFNC was feasible as home‐based support in ALS patients intolerant to NIV, warranting prospective comparative evaluation.