Non-invasive ventilation (NIV) and high-flow nasal therapy (HFNT) in palliative care: a critical narrative review

Dyspnoea is a prevalent, debilitating symptom in advanced life-limiting illnesses. While opioids and non-pharmacological measures remain foundational, refractory breathlessness presents a major palliative challenge.

To critically appraise the evidence regarding patient selection, comparative tolerability, adverse effects and ethical considerations of non-invasive ventilation (NIV) and high-flow nasal therapy (HFNT) in palliative care.

A comprehensive narrative review of literature from PubMed, Embase and Cochrane Library (from inception to June 2026) and major clinical guidelines was conducted.

NIV is best supported in hypercapnic respiratory failure (PaCO >45 mm Hg), showing benefits in chronic obstructive pulmonary disease exacerbations, pulmonary oedema and amyotrophic lateral sclerosis (ALS). In advanced cancer, NIV reduces dyspnoea primarily in hypercapnic patients but mask discomfort and communication barriers limit tolerability. Conversely, HFNT has emerged as a superiorly tolerated option in hypoxemic failure-particularly in end-stage interstitial lung disease (ILD) and advanced cancer-providing significant dyspnoea relief while preserving oral intake and verbal communication until the end of life. Time-limited trials (<1 hour for NIV; 2 hours for HFNT) help identify early responders. Ethical challenges include potential overtreatment and support withdrawal complexities.

Respiratory support selection should be guided by respiratory physiology (hypercapnic vs hypoxemic), explicit goals of care and tolerability. NIV remains optimal for hypercapnic failure, whereas HFNT offers superior comfort and preserves communication in hypoxaemic patients. Robust randomised trials are needed.