A typical HFNC system consists of a flow generator, active heated humidifier, single-limb heated circuit, and nasal cannula. According to the monitored oxygen concentration, FiO2 can be titrated with flows up to 60 L/min. The differences between NIV and HFNC are the interfaces as well as consistent pressure versus the ability to provide different inspiratory and expiratory pressures. Although NIV interfaces add to the anatomic dead space, HFNC delivery actually decreases dead space. Because HFNC is an open system, it does not actively enhance tidal volume; however, it does improve alveolar ventilation by washing out anatomic dead space. The simplicity and excellent patient tolerance of the system is attractive, and, owing to these advantages, the use of HFNC for adults who are critically ill has been dramatically increasing. HFNC may make it easier to initiate earlier respiratory support, and the device has the potential to decrease the necessity or duration of mechanical ventilation. As described above, HFNC is a simple system composed of a flow generator, humidifying device, inspiratory limb, and nasal interface
It Consist of: