High-Flow Nasal Cannula for Patients with COVID-19 Acute Hypoxemic Respiratory Failure

High-flow nasal cannula (HFNC) is a noninvasive oxygenation modality that delivers heated and humidified oxygen. It possesses several advantages due to the unique physiological effects on the lung and ventilation mechanics compared to other modes of oxygen therapy. The use of HFNC is tolerable, comfortable, and easy to set up. Current evidence indicates that the use of HFNC in critically ill patients with coronavirus disease 2019 (COVID-19)-acute hypoxemic respiratory failure (AHRF) is noninferior to noninvasive ventilation in the reduction of endotracheal intubation rate. Early identification of HFNC failure is vital to avoid delaying intubation. However, multiple knowledge gaps exist, and unpowered observational studies limit HFNC incorporation into strong recommendations. The low dispersion of particles demonstrates the feasibility of HFNC; yet, an appropriate setting and precautions should be maximized. Here, we review the recent evidence of HFNC implications in the management of patients with COVID-19-AHRF.