Background: High-flow nasal cannula (HFNC) oxygen therapy comprises an air/oxygen blender, an active humidifier, a single heated circuit, and a nasal cannula. It delivers adequately heated and humidified medical gas at up to 60 L/min of flow and is considered to have a number of physiological effects: reduction of anatomical dead space, PEEP effect, constant fraction of inspired oxygen, and good humidification. While there have been no big randomized clinical trials, it has been gaining attention as an innovative respiratory support for critically ill patients.

Evidence with critically ill adults is needed; however, physicians apply it to a variety of patients with diverse underlying diseases: hypoxemic respiratory failure, acute exacerbation of chronic obstructive pulmonary disease, post-extubating, pre-intubation oxygenation, sleep apnea, acute heart failure, patients with do-not-intubate order, and so on. Many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces the need for escalation of respiratory support in patients with diverse underlying diseases.

Some important issues remain to be resolved, such as its indication, timing of starting and stopping HFNC, and escalating treatment. Despite these issues, HFNC oxygen therapy is an innovative and effective modality for the early treatment of adults with respiratory failure with diverse underlying diseases.

The use of the heated and humidified high-flow nasal cannula has become increasingly popular in the treatment of patients with respiratory failure through all age groups. This article will examine the main mechanisms of action attributed to the use of the high-flow nasal cannula and review the indications in adult populations. It is unclear which of the mechanisms of action is the most important, but it may depend on the cause of the patient’s respiratory failure. This article describes the mechanism of action in an easy-to-remember mnemonic (HIFLOW); Heated and humidified, meets Inspiratory demands, increases Functional residual capacity (FRC), Lighter, minimizes Oxygen dilution, and Washout of pharyngeal dead space. Will also examine some of the main indications for its use in both the adult. The data for the use of high-flow nasal cannula is growing, and currently, some of the main adult indications include hypoxemic respiratory failure due to pneumonia, post-extubation, pre-oxygenation prior to intubation, acute pulmonary edema, and use in patients who are "do not resuscitate or intubate". The main adults with bronchiolitis, but other indications are being studied, such as its use in asthma, croup, pneumonia, transport of a critically ill patient, and post-extubating.

As medical professionals staff nurses should know the application and limitations. She/he might be aware of machines and indications but not aware of the application and administrative flow on adults means it's not effective for this kind of developmental equipment. A healthcare professional should identify the need and application of machines is necessary to know.