Clinically, due to various reasons that lead to hypoxia in the body, it is easy to lead to hypoxemia and hypercapnia causing dyspnea and respiratory failure, which requires oxygen inhalation, and the clinical formula for oxygen inhalation concentration is: Inhalation oxygen concentration (%) = 21 + 4 x oxygen flow rate (L/min). Different diseases will have different oxygen concentrations, such as for chronic obstructive pulmonary emphysema, chronic bronchitis, and type II respiratory failure patients, oxygen inhalation can be given at oxygen concentrations lower than 35%. For patients with acute respiratory distress syndrome, acute dyspnea, and acute obstruction of the airway, resulting in type I respiratory failure, oxygen inhalation at a concentration greater than 35% is given.