High-flow nasal oxygen therapy

Nowadays, with the improvement of social and economic levels, medical technology has also developed accordingly. In order to cope with various medical problems and treat various difficult-to-treat diseases, many new treatment methods have been researched and applied in clinical medicine. High-flow nasal oxygen therapy is one of them. Next, I will give you a detailed introduction to the characteristics of nasal high-flow oxygen therapy.

1. High flow heating and humidification oxygen supply

HFNC can deliver heated and humidified high-concentration oxygen through a nasal cannula, with an airflow rate of up to 60L/min. Since the airflow rate can be set to exceed the peak inspiratory flow level of most patients with respiratory failure, the oxygen concentration is kept constant. The heating and humidification functions of HFNC can protect the airway mucosa and enhance the cleaning ability of the mucociliary membrane. Reasonable airway humidification can dilute respiratory secretions, keep the airways open and moist, maintain normal respiratory function, and effectively prevent complications such as lung infections.

2. Increase functional residual capacity

Riera et al. evaluated the relationship between high-concentration nasal cannula oxygen inhalation, body position and end-expiratory volume using electrical impedance tomography and pointed out that regardless of the posture adopted, inhalation of high-flow airflow through a nasal cannula can increase the overall regional end-expiratory lung impedance by increasing the functional residual capacity.

Clinical application of high-flow nasal cannula (HFNC) 1. Application in patients with acute hypoxemic respiratory failure

At the same PaCO2 level, patients receiving HFNC had a slower respiratory rate, suggesting a reduction in pulmonary dead space. The increase in pulmonary dead space can increase the mortality rate of patients with acute respiratory failure caused by hypoxemia and acute respiratory distress syndrome. The average tidal volume in the noninvasive ventilation group exceeded 9 ml/kg body weight, and the degree of lung injury increased significantly, resulting in a higher mortality rate than in the high-flow oxygen therapy group. 2. Applicable to patients with respiratory failure who have not undergone endotracheal intubation

The included patients were mainly those with pulmonary fibrosis, pneumonia, chronic obstructive pulmonary disease, cancer, hematological malignancies and congestive heart failure, and the median HFNC treatment time was 30 hours. HFNC can provide adequate oxygenation and serve as an alternative noninvasive ventilation method for patients with hypoxic respiratory distress who refuse endotracheal intubation.

3. Used in patients with heart failure

A foreign literature study used HFNC in 10 patients with grade III heart failure. Under the guidance of echocardiography, it was found that with the increase in output flow, the preload of the heart gradually decreased, and the respiratory rate also dropped from 23 times/min before the use of HFNC to 17 times/min and 13 times/min, thus benefiting patients with grade III heart failure. Subsequently, HFNC was used, and it was found that the use of traditional Venturi masks could not meet the patient's oxygenation needs during the stable period after non-invasive ventilation. After using HFNC, oxygenation was significantly improved and the degree of dyspnea was significantly reduced.

4. Applicable to patients after extubation, endotracheal intubation and those who need bronchoscopy

In a single-center study, the effects of HFNC and oxygen inhalation via Venturi mask were compared in patients after extubation. The results showed that the PaO2/FiO2 was higher in the HFNC group, and the 36-hour blood oxygen partial pressure (PaO2) was higher. In addition, fewer patients in the HFNC group required noninvasive positive pressure ventilation or endotracheal intubation. HFNC is used in invasive alveolar lavage operations to improve the safety of the operation. Some reports have suggested that HFNC technology can also be used during endotracheal intubation. summary

High-flow nasal cannula (HFNC) is a new oxygen therapy method that can effectively improve oxygenation, reduce the probability of invasive and non-invasive mechanical ventilation, and use heating and humidification devices to make the gas reach the most suitable temperature and humidity for the human body, thereby improving comfort. It has obvious advantages over traditional oxygen therapy methods. HFNC therapy has achieved some satisfactory results. With the widespread application of HFNC, more options are provided for clinical oxygen therapy.