How long it takes to react to the infusion of air is mainly related to the volume of air that enters, which should be analyzed in a specific way and should not be generalized. If a small amount of gas, such as less than 10 ml, is injected into the infusion at one time, the patient usually does not show abnormal symptoms. If an excessive amount of gas is injected at one time, such as more than 100ml, the patient will have poor breathing, suffocation, breathlessness, blue lips, or even coughing, coughing, hemoptysis and other serious phenomena within a few minutes, which may indicate that the gas has entered the pulmonary circulation and caused air pulmonary embolism. At this time, the situation is very critical and the resuscitation methods are limited, and the mortality rate of patients is high. If the patient has no abnormal or uncomfortable symptoms after observing 15-30 minutes after inputting a small amount of gas, it is less likely to recur pulmonary embolism. At present, the function of clinical infusion equipment is relatively good, and it rarely happens that air enters the blood vessel, so there is no need to worry excessively.