High flow nasal cannula: Mechanism of action, indications, benefits, and potential risks

High Flow Nasal Cannula (HFNC) is a non-invasive oxygen therapy device with high flow that is increasingly used to treat patients with acute respiratory failure, especially in hypoxemic cases. HFNC offers several advantages, such as optimal humidification, reduced breathing work, and increased oxygenation, reducing the need for invasive mechanical ventilation. This paper aims to elucidate the mechanism of action, indications, clinical monitoring, benefits, and potential risks of HFNC use in adult patients with various clinical conditions. HFNC has various beneficial physiological effects, including increasing oxygenation by reducing anatomical dead space and producing end-expiratory positive pressure (PEEP). The main indications for HFNC include acute hypoxemic respiratory failure, post-extubation, and patients with “do not intubate” (DNI) status. In addition to its benefits, HFNC has risks, such as delayed intubation, hypercapnia, and gastric inflation, requiring close monitoring. HFNC is an effective and easily tolerated modality for treating mild to moderate acute respiratory failure. However, more research is needed to determine optimal use criteria and guidelines for therapy escalation.