Intravenous injection of large amounts of air can lead to air embolism, causing pulmonary embolism, pulmonary edema and other conditions that can be life-threatening in severe cases. If a small amount of air enters the vein, there is usually no great harm, but the patient should be placed in a semi-recumbent position, receive oxygen, and monitor the changes in vital signs, such as heart rate, blood pressure, pulse rate, oxygen saturation, etc. At the same time, the patient’s general condition is observed for nausea, vomiting, dizziness and other symptoms. Generally observe for about 15 minutes, if the patient does not have the above symptoms, it is fine, because a small amount of air entering the blood can be expelled from the body through the pulmonary circulation.