High-flow nasal cannula therapy in patients with COPD

Non-invasive ventilation (NIV) plays a critical role in the treatment of acute hypercapnic respiratory failure in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) by improving alveolar ventilation, reducing the work of breathing, minimizing the need for endotracheal intubation, and decreasing both the length of hospital stay and mortality. For patients intolerant to NIV, a trial of high-flow nasal cannula (HFNC) is recommended. High-flow nasal cannula therapy is a method of non-invasive respiratory support in which humidified, warmed, oxygen-enriched air is delivered through a nasal cannula at high flow rates. Several studies have investigated the physiological effects of HFNC in COPD patients and found that HFNC improves mucociliary clearance, decreases nasopharyngeal dead space, increases CO2 washout, and reduces respiratory effort. Recently, HFNC has gained popularity as a method of respiratory support and is increasingly used in daily clinical practice for patients with acute exacerbation of COPD. Although the clinical benefits of using HFNC at home are still poorly understood, some research results support the prospect of widespread use of HFNC in chronic respiratory diseases. The aim of this narrative review is to describe the physiological effects of HFNC and to highlight the results of key studies investigating the role of HFNC in patients with COPD.