Air Embolism

What Is An Air Embolism? What Causes An Air Embolism?

An embolism in a medical context refers to any large moving mass or defect in the blood stream. An air embolism is an air bubble trapped in a blood vessel. When an air bubble travels along an artery, it moves through a system of blood vessels that gradually become narrower. At some point, the embolus will block a small artery and cut off the blood supply to a particular area of the body.

For example, when a person scuba dives with compressed air, they take in extra oxygen and nitrogen. The body uses the oxygen, but the nitrogen is dissolved into the blood, where it remains during the dive. As one swims back toward the surface after a deep dive, the water pressure around decreases. If this transition occurs too quickly, the nitrogen does not have time to clear from the blood. Instead, it separates out of the blood and forms bubbles within tissues or blood. It is these nitrogen bubbles that cause decompression sickness.

For venous air embolisms, death may occur if a large bubble of gas becomes lodged in the heart, stopping blood from flowing from the right ventricle to the lungs. However, experiments in animals show that the amount of gas necessary for this to happen is quite variable, and also depends on several other factors, such as body position.

According to Medilexicon's medical dictionary:

An Air Embolism is an embolism caused by air bubbles in the vascular system; venous air embolism can result from the introduction of air through intravenous lines, especially central lines, and generally must be substantial to block pulmonary blood flow and cause symptoms; arterial air embolism is also usually iatrogenic, caused by cardiopulmonary bypass or other intravascular interventions, occurs rarely after penetrating lung injury; small amounts of arterial air can cause death by blockage of coronary and/or cerebral arteries; small bubbles introduced into the venous system may similarly cause symptoms if they reach the arterial side.

The word "embolus" comes from the Greek "embolos" meaning a wedge or plug. "Embolos" was derived from "en" (in) + "ballein" (to throw) so an embolus is something thrown in.

What are the symptoms of An Air Embolism?

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.

Symptoms of decompression sickness include joint pain, dizziness, extreme fatigue, tingling or numbness, weakness in arms or legs, skin rash and unconsciousness or paralysis in severe cases.

In particular, a large air embolism in the arteries to the brain will cause immediate loss of consciousness and often causes convulsions. It may also cause a stroke.   Learn more