The HFNC machine has the following functions:
(1) It provides a stable high oxygen concentration and improves blood oxygen quickly and effectively.
(2) It can flush the anatomical and physiologic dead space to reduce the re-inhalation of carbon dioxide.
(3) It can form a certain positive airway pressure to keep the airway open.
(4) It can fully humidify and warm the airway to make the mucociliary cleaning function in the best state.
(5) It offers comfortable experiences for patients and improves compliance with oxygen therapy.
The HFNC machine can provide warm and humid high-flow oxygen through the nasal cannula, and the air volume can reach up to 60L/min. In this way, the airflow can be set to exceed the peak inspiratory flow level of patients with respiratory failure to ensure a constant oxygen flow.
The heating and humidification function of the HFNC machine can protect the airway mucosa and enhance the cleaning ability of mucous cilia. Reasonable airway humidification can dilute airway secretions, keep the airway open and moist, maintain the normal function of the airway, and effectively prevent complications like lung infection.
The relationship between high-flow nasal cannula, body position and end-expiratory volume evaluated by electrical impedance tomography shows inhaling high-flow airflow through the nasal cannula by any postures all can increase the entire area and increase functional residual capacity and end-expiratory lung volume.
Potassium is mainly absorbed from food and excreted by the kidneys in the urine. Patients with chronic renal insufficiency have less urine than normal people, which makes it easier for potassium to accumulate in their bodies. Therefore, it is very important to closely observe patients' urine volume. It is necessary to accurately record the 24-hour urine volume for incontinent patients. In order to accurately observe the urine volume, it is not allowed to leave the urinary catheter.