Regardless of the disease caused by the oxygen saturation drop, oxygen partial pressure drop need oxygen, the most common way is the nasal catheter oxygen, because the operation is relatively simple, and the patient is also more easily accepted. The patient’s nasal cavity should be checked for foreign bodies and whether the cavity is clear, followed by cleaning the patient’s nasal cavity with a cotton swab dipped in saline, connecting the oxygen meter to the oxygen cylinder and connecting the wetting bottle, which is filled with the appropriate amount of sterilized water and then connecting the oxygen tube, checking whether there is any air leakage from the oxygen tube, and if there is no air leakage, inserting the nasal cannula into the patient’s nasal cavity and adjusting the oxygen tube to ensure that it is comfortable to wear and not too loose or too tight. Turn on the flow meter and adjust the oxygen flow rate to 1-2 liters/minute to check if the oxygen flow is smooth. If the nasal cavity feels dry or broken during the oxygen intake process, make sure to drink more water and apply some paraffin oil or glycerin to the nasal cavity with a cotton swab to reduce the discomfort.