A small amount of air entering the bottle can have no manifestation, and a large amount of air entering can lead to arterial embolism, which can lead to chest pain, limb paralysis and other symptoms. 1. During infusion, if gas enters the blood vessels, it may cause air embolism; a small amount of air entering can quickly dissolve in the blood and normally does not cause serious reaction, a large amount of gas entering will increase the risk of damage. 2. When gas enters the heart, a large number of bubbles will be formed under the action of cardiac contraction, and the bubbles will enter many parts of the body with the blood circulation, such as blocking the blood vessels of the heart, which can lead to myocardial ischemia, chest pain symptoms, and in severe cases, sudden death can occur. 3. Gas into the cerebral blood vessels can lead to cerebral blood vessel blockage, acute cerebral infarction, the patient can appear limb paralysis, serious or even coma. Infusion should be strictly excluded from the gas, to avoid gas into the body, to prevent the occurrence of gas embolism, if any discomfort promptly inform the doctor.