HFNC machine, the abbreviation of high flow nasal cannula machine, refers to the therapeutic instrument that can continuously provide patients with a relatively constant oxygen concentration (21%~100%), temperature (31~37℃) and high flow rate (8 ~80 L/min) inhaling gas. The high flow nasal cannula machine mainly includes an air-oxygen mixing device, a humidification treatment instrument, a high-flow nasal congestion and connecting breathing tubes.
The history of humans starting oxygen therapy can be traced back to the latter part of the 18th century, and the use of rubber-made nasal catheters for oxygen therapy began in the early 20th century.
In 1987, the United States developed the oxygen therapy heating and humidification device MT-1000 with a maximum flow rate of 20 L/min, which is used in oxygen therapy for patients with cystic pulmonary fibrosis to promote the discharge of lower respiratory tract secretions.
In the past 10 years, the HFNC machine has entered a stage of rapid development and widespread clinical application. The international mainstream HFNC machine adopts the working principle of non-invasive breathing machine: air-oxygen mixing is carried out with an air-oxygen mixer, and the inhaled oxygen concentration (FiO2) is 21%~100 %. The turbine is used to provide high-flow gas, and the inhaled gas is heated and humidified by the heating humidifier and pipe heating guide wire used in the ventilator, and the temperature and oxygen concentration are dynamically adjusted by real-time monitoring of the temperature and oxygen concentration at the proximal end of the patient.
In addition, some ventilator manufacturers have installed the function of HFNC machine on invasive and non-invasive breathing machine, further expanding the scope of clinical application of the ventilator, which is also the direction of future development. The history of the use of HFNC machines in China is only about 5 years. It is innovative on the basis of imitating the internationally-used HFNC machine treatment in the early stage, and forms its own characteristics in a short period of time, such as automatic adjustment and precise adjustment of FiO2 (21%~100%), the temperature control accuracy can reach ±1 ℃, and the breathing circuit adopts disinfection-free air technology.