First, if the air entering is within 1ml, close observation is sufficient, because the body will automatically expel the air within 1ml. Secondly, if the air that enters is within 1-5 ml, it is necessary to monitor the patient’s condition clearly and strictly, to monitor the patient’s vital signs such as heart rate, blood pressure, pulse, oxygen saturation and body temperature, and to deal with any abnormal changes immediately. Thirdly, if the air entering while hanging saline is more than 5-20ml, immediate symptomatic treatment is needed. Patients should be placed in the left lateral position and receive oxygen immediately, and vital signs should be monitored on the basis of relieving patients’ tension and anxiety. Fourthly, if the amount of air entering when hanging saline exceeds 20ml, there is a risk of lethality, and immediate resuscitation treatment is needed.