Expanding roles of high-flow nasal cannula beyond acute care: Home use, rehabilitation, and palliative care.

High-flow nasal cannula (HFNC) therapy is an established modality for noninvasive respiratory support in acute hypoxemic respiratory failure. More recently, its use has expanded beyond acute care to home, rehabilitation, and palliative settings. This narrative review summarizes the current evidence on the long-term and non-acute applications of HFNC in adult patients. A PubMed search (2010-2025) identified studies on domiciliary HFNC for chronic respiratory failure as well as its use in rehabilitation and palliative care. In chronic obstructive pulmonary disease (COPD), multiple randomized controlled trials have shown that long-term HFNC use reduces exacerbation frequency and improves quality of life (QOL), although effects on hospitalizations and mortality remain uncertain. In bronchiectasis, available studies suggest reduced exacerbations and symptom improvement despite limited high-quality evidence. In interstitial lung disease (ILD), findings are heterogeneous, with some low-certainty studies reporting benefits for dyspnea, cough, and exercise tolerance. During exercise and pulmonary rehabilitation, HFNC may reduce dyspnea, improve endurance, particularly in COPD, and attenuate oxygen desaturation in ILD. In palliative care, HFNC effectively relieves dyspnea and may improve comfort, communication, and QOL in patients with advanced diseases. Overall, HFNC appears to be a versatile respiratory support modality in chronic and non-acute settings. However, further high-quality studies are needed to define optimal indications and long-term outcomes. Careful patient selection, clear therapeutic goals, and multidisciplinary preparation are essential for safe and effective implementation.