In acute pulmonary edema, the purpose of ethanol wetting is, most importantly, to reduce alveolar surface tension. Patients with pulmonary edema have excessive alveolar exudate and are in an ischemic, hypoxic state, and oxygen is administered to improve the patient’s hypoxic state. Administration of high-flow oxygen, usually 6-8 L/min, administered via ethanol wetting, can improve patient ventilation, dilate tracheal and bronchial function, and most importantly, reduce intra-alveolar surface tension, prevent alveolar rupture, improve gas ventilation status, reduce dead space area, improve ineffective space, and improve ventilation/blood flow ratio imbalance. In acute pulmonary edema, high-flow oxygen inhalation is usually given, but when inhaling high-flow oxygen, the time must not be too long, as oxygen toxicity may easily occur.