how much air bubble in iv is dangerous

An air bubble in an IV becomes dangerous depending on its volume relative to the patient's body weight and the rate it is infused. Generally, patients may tolerate up to 1 cc (ml) of air per kilogram of body weight without significant harm. Beyond this threshold, especially around 3 to 5 cc/kg, air embolism—a blockage in blood vessels caused by air entering the bloodstream—can occur, which can be fatal. For example, injecting around 350 ml of air into a 70-kg patient can cause serious complications or death. Rapid infusion of even smaller volumes, like 20 ml, can sometimes be fatal. Small air bubbles under 0.2 ml are typically not hazardous, but an air volume of 300-500 ml infused quickly is considered fatal for adults. The danger also depends on the infusion speed and patient conditions, like the presence of heart defects, which can increase vulnerability. To avoid risk, IV lines must be properly primed to remove air bubbles before insertion. In summary, even small amounts of air should be avoided, and volumes exceeding about 1 cc/kg body weight can be dangerous, with larger volumes (several hundred ml) being potentially lethal if introduced rapidly into the bloodstream.