Why does a bubble in a bloodstream cause your body to go haywire?

Question

Why does a bubble in a bloodstream cause your body to go haywire?

In: 78

Answer 1

3 to 5 ml/kg of air injected into the circulation is thought to be fatal. However it’s considerably less if the patient has a ‘hole’ in their heart (pfo, asd, vsd).

In a normal heart, such a large volume of air – an air embolism – can get trapped in the right side leading to a sudden and dramatic fall in cardiac output and cardiac arrest. I’ve seen it. The air can also get trapped in the pulmonary circulation and, like a pulmonary embolism, cause a cardiac arrest.

These air emboli can happen by accident. If a patient has a central venous catheter in place and a cap comes off, air can get sucked into the circulation. Brain surgery in the upright position can also cause this as can any upright surgery where veins are open to air.

A hole in the heart connecting the right side to the left side is particularly dangerous. A relatively small volume of air can enter the circulation on the right side, cross to the left side (completely bypassing the lungs) and go into the brain circulation causing a stroke. Again, I’ve seen this too. The worrying thing? 10 – 20% of adults have asymptomatic PFOs (patent foramen ovale). That’s why it’s a good idea to minimise the amount of air that gets into the venous circulation.

Answer 2

3 to 5 ml/kg of air injected into the circulation is thought to be fatal. However it’s considerably less if the patient has a ‘hole’ in their heart (pfo, asd, vsd).

In a normal heart, such a large volume of air – an air embolism – can get trapped in the right side leading to a sudden and dramatic fall in cardiac output and cardiac arrest. I’ve seen it. The air can also get trapped in the pulmonary circulation and, like a pulmonary embolism, cause a cardiac arrest.

These air emboli can happen by accident. If a patient has a central venous catheter in place and a cap comes off, air can get sucked into the circulation. Brain surgery in the upright position can also cause this as can any upright surgery where veins are open to air.

A hole in the heart connecting the right side to the left side is particularly dangerous. A relatively small volume of air can enter the circulation on the right side, cross to the left side (completely bypassing the lungs) and go into the brain circulation causing a stroke. Again, I’ve seen this too. The worrying thing? 10 – 20% of adults have asymptomatic PFOs (patent foramen ovale). That’s why it’s a good idea to minimise the amount of air that gets into the venous circulation.