Detection and prevention of hypoxic episodes People with cyanotic congenital heart disease have varying degrees of cyanosis, pestle fingers, crying, suckling, shortness of breath after feeding and activity, and even hypoxic episodes (manifested by crying, restlessness, shortness of breath, nasal agitation, pallor, terminal flushing, and refusal to eat) before surgery. Most patients have squatting with motor system retardation, low weight, malnutrition or combined anemia. To prevent the occurrence of hypoxic attacks, we should pay attention to 1. Drink more water in general to prevent the blood from being too concentrated. Patients with high hemoglobin and high blood viscosity need to drink more water at ordinary times. 2, usually according to medical advice oxygen; 3, appropriate to limit the activities of seriously ill children; 4, reduce the stimulating factors (such as fright, etc.) to the children; 5, when the hypoxic attack should be suspended feeding, try to keep the children calm, adjust the flow of oxygen, and promptly notify the medical staff. Precautions for oxygen inhalation Patients with cyanotic congenital heart disease have different degrees of cyanosis, pestle finger, crying, suckling, shortness of breath after feeding and activity and even hypoxic attacks before surgery. Usually, the doctor will give the child different levels of oxygen depending on the situation, which usually includes: low-flow oxygen (2-3L/min, three times a day, one hour at a time) and continuous nebulized oxygen (4-6 hours of continuous oxygen for patients after contrast surgery). Parents should administer oxygen strictly according to medical advice, as oxygen toxicity can also occur if too much oxygen is administered.