Interventional procedures Interventional radiology procedures, cardiac, and neurosurgical procedures can predispose to<unk> . Besides, increasing use of pump injectors for contrast delivery, and percutaneous intervention to the lungs also increases the risk of<unk> . Decompression illness Gas<unk>  is a diving disorder suffered by underwater divers who breathe gases at ambient pressure, and can happen in two distinct ways: * Pulmonary barotrauma: Air bubbles can enter the bloodstream as a result of gross trauma to the lining of the lung following a rapid ascent while holding the breath; the air held within the lung expands to the point where the tissues tear (pulmonary barotrauma). This is easy to do as the lungs give little warning through pain until they do burst. The diver will usually arrive at the surface in pain and distress and may froth or spit blood. A pulmonary barotrauma is usually obvious and may present quite differently from decompression sickness. *Decompression sickness: Inert gas bubbles form in the bloodstream if the gas dissolved in the blood under pressure during the dive is not allowed sufficient time to be eliminated in solution on ascent. The symptoms may be subtle and not immediately noticeable, and may develop for some time after surfacing. Ventilator induced pulmonary barotrauma Trauma to the lung can also cause an<unk> . This may happen after a patient is placed on a ventilator and air is forced into an injured vein or artery, causing sudden death. Breath-holding while ascending from scuba diving may also force lung air into pulmonary arteries or veins in a similar manner, due to the pressure difference. Direct injection Air can be injected directly into a vein or artery accidentally during clinical procedures. Misuse of a syringe to meticulously remove air from the vascular tubing of a hemodialysis circuit can allow air into the vascular system. Venous<unk>  is a rare complication of diagnostic and therapeutic procedures requiring catheterization of a vein or artery. If a significant<unk>  occurs, the cardiovascular, pulmonary, or central nervous system may be affected. Interventions to remove or mitigate the<unk>  may include procedures to reduce bubble size, or withdrawal of air from the right atrium. The lethal dose for humans is considered theoretically between 3 and 5 ml per kg. It is estimated that 300-500 ml of gas introduced at a rate of 100 ml per sec would prove fatal. Other There have been rare cases of<unk>  being caused by air entering the bloodstream from the uterus or tears in female genitalia. The risk appears to be greater during pregnancy. Cases have been reported that resulted from attempts to perform an abortion by syringing. These appear to have been due to damage to the placenta allowing air to enter the bloodstream. Risk factors Patent foramen ovale in underwater divers is considered a risk factor for arterial gas<unk>  due to shunt of what would otherwise be asymptomatic venous bubbles into the systemic arteries.
Air embolism
Pulmonary aspiration
Aspiration pneumonia
Pulmonary hemorrhage
Airway obstruction
Right heart strain
Thoracic insufficiency syndrome
Lung infarction