Patients with chronic obstructive pulmonary disease should not be given high-flow oxygen. Patients with chronic obstructive pulmonary disease often have a combination of type II respiratory failure, that is, hypoxemia combined with hypercapnia, so if high-flow oxygen is given, it will have a certain inhibitory effect on the respiratory center, so that the patient’s ventilation will decrease, which will lead to an increase in oxygen saturation; however, because the patient’s respiratory rate decreases, it will also lead to an increase in carbon dioxide retention, which may lead to a further increase in carbon dioxide elevation, which in turn will lead to pulmonary encephalopathy, and the patient may become comatose.