A small amount of air entering the infusion is generally fine and does not cause much effect on the body, but you should still avoid entering air during infusion. If a small amount of air is entered, the gas will be dispersed into the alveolar capillaries, absorbed by the blood, combined with hemoglobin, or discharged out of the body with respiration through the diffusion effect of the alveoli, causing no damage to the body. If the amount of air entering is large, more than 50 ml, it may exceed the absorption capacity of the blood, blocking in the entrance of the pulmonary artery so that the blood can not enter, possibly leading to pulmonary embolism or heart failure. Dizziness, dyspnea, chest tightness, wheezing, cyanosis and other clinical symptoms of varying degrees of severity, shock, cardiac arrhythmia or even death. So a small amount of air into the blood does not have much effect on the body, if there are clinical symptoms such as severe coughing, chest pain, chest tightness, to immediately clamp the venous pipeline, to prevent further air into the body, let the patient to keep the head down and feet high left lateral position, so that the air to avoid the entrance of the pulmonary artery, the air may be mixed into a bubble with the heartbeat, small amounts of time into the pulmonary artery. At this time, promptly inform the doctor, cooperate with the doctor to take the next emergency measures.