How long it takes for air to get into an IV to be dangerous usually has little to do with the time of day and depends largely on the amount of air that enters the body. Usually a small amount of air bubbles enter the body during a patient’s infusion, and these bubbles may enter the lungs, where most of them can be absorbed on their own. If a larger amount of gas enters the body during an IV infusion, this may result in a severe air embolism and the patient may experience symptoms such as chest discomfort or pain behind the sternum. The average patient is usually at no apparent risk if less than 1ml of air enters the blood vessel during an infusion. If the amount of air that enters the vein during IV infusion is 1-5 ml, the patient’s blood pressure, pulse, heart rate and other indicators need to be strictly monitored for at least 4-8 hours before the danger can be eliminated. If the patient finds any abnormalities in the infusion tube, he/she should seek medical attention to avoid delaying the condition.