A Review of High-Flow Nasal Cannula Oxygen Therapy in the Management of Respiratory Failure and Chronic Obstructive Pulmonary Disease

High-flow Nasal Cannula (HFNC) oxygen therapy is gaining traction globally as a treatment for respiratory failure. There are several physiological benefits and there may be a growing patient preference for HFNC. In this narrative review, we aim to outline the basic mechanisms of HFNC, who can use it and review the literature regarding its utility both in the critical care setting, as well as in the home setting for chronic hypercapnic respiratory failure with an emphasis on Chronic Obstructive Pulmonary Disease (COPD). The role of non-pharmacological interventions like non-invasive ventilation (NIV) and HFNC in the prevention of hospital readmissions following acute exacerbations of COPD (AECOPD) is an area of increasing importance because randomised controlled trials and systematic reviews have found measures like nurse-led predischarge bundles to be clinically ineffective and to have a high cost per quality adjusted life year. This review therefore considers the evidence of NIV vs HFNC in the context of AECOPD and the application of HFNC at home in the prevention of AECOPD. We also look at applications of HFNC in specific settings, such as in the peri-operative period, emergency department, acute (mainly Critical Care) setting including in immunocompromised patients and palliative care.