Air in blood vessels

[Hrishi87]

Sorry for necroposting but is there any way that about 40-60ml of air injected into the forearm vein prove fatal? Will the air be dissolved on its way back?
Thanks in advance,
Hrishi.

[running_coach]

@Hrishi87

Sorry for necroposting but is there any way that about 40-60ml of air injected into the forearm vein prove fatal? Will the air be dissolved on its way back?
Thanks in advance,
Hrishi.

Need answer fast?
Reported.

[Hrishi87]

@runner pat

Need answer fast?
Reported.

LOL no!
One of my well known friends attempted this and nothing’s happened to him so I was just curious. And yeah, I can wait for an answer!
Hrishi.

[Michael63129]

@WhyNot

An air bubble can block the blood from getting through the vessel, causing something on the other side to not get the nutrients and oxygen it needs. This is usually not immediately fatal, of course. When it is fatal, it’s because the bubble, or embolism stops blood from flowing into the right ventricle of the heart. This causes a heart attack, and often death.

(emphasis mine)

Say what? I think people need to look up the medical definition of a “heart attack”…

The phrase heart attack is sometimes used incorrectly to describe sudden cardiac death, which may or may not be the result of acute myocardial infarction. A heart attack is different from, but can be the cause of cardiac arrest, which is the stopping of the heartbeat, and cardiac arrhythmia, an abnormal heartbeat. It is also distinct from heart failure, in which the pumping action of the heart is impaired; however severe myocardial infarction may lead to heart failure.

Maybe if the air gets into a coronary artery, but air in the heart chambers themselves does NOT cause a"heart attack"; heart failure would be a better description of what would happen if the heart can’t pump blood anymore due to air in it.

On a related note, when somebody bleeds to death from a massive wound, say the loss of an arm, does air get sucked into the veins (after most of the body’s blood has bled out; veins normally have some pressure in them relative to outside the body which is why they bleed)?

[Dog80]

Does the body somehow bleed the air from the blood system? Or do these air bubbles stay there indefinitely?

[Der_Trihs]

@Dog80

Does the body somehow bleed the air from the blood system? Or do these air bubbles stay there indefinitely?

Sounds like the body absorbs it:

@picunurse

Less than 100 ccs will eventually be absorbed, over several hours, making it important that the patient stay in the position.

[Iggy]

Small air bubbles are routinely evident in scuba divers. Imaging by doppler ultrasound shows bubbles evident even in the absence of any symptoms. Bubbles are filtered out in the lungs in normal pulmonary circulation.

Scuba diving and the heart. Cardiac aspects of sport scuba diving

…During decompression a free gas phase may form in supersaturated tissues, resulting in the generation of inert gas microbubbles that are eliminated by the venous return to the lungs under normal circumstances. …

[WhyNot]

@Michael63129

(emphasis mine)

Say what? I think people need to look up the medical definition of a “heart attack”…

Maybe if the air gets into a coronary artery, but air in the heart chambers themselves does NOT cause a"heart attack"; heart failure would be a better description of what would happen if the heart can’t pump blood anymore due to air in it.

On a related note, when somebody bleeds to death from a massive wound, say the loss of an arm, does air get sucked into the veins (after most of the body’s blood has bled out; veins normally have some pressure in them relative to outside the body which is why they bleed)?

Sure thing, boss. Send the medical dictionary back in the TARDIS and I will have gotten right on that. Indeed, I was using a layperson’s version of “heart attack” to mean “heart failure”. I was a layperson at the time, you see.
Little teeny tiny bubbles can move along the blood vessels until they get to the blood vessels that exchange air with the lungs, and then they move through the blood vessel wall into the alveloli (lung tissue) and are exhaled with everything else you exhale.

[AaronX]

@Colophon

I assume he means “prime” as in priming a pump - filling it with liquid and expelling air in order to get a seal. Not sure if that could apply to the heart though…

I’ve heard this too. The heart isn’t a continuous pump - it fills up, then squeezes using valves to make the blood exit the right direction. If a chamber fills with compressible air, the air won’t leave the chamber when squeezed. In essence the air gets stuck in the chamber, and the pump stops working.

[Hrishi87]

So, what happened in my friend’s case? Was the volume not enough to cause a serious damage? Or did the injected air turn into tiny bubbles on it’s way back to the heart and got absorbed?
Hrishi.

[johnpost]

@Colophon

I assume he means “prime” as in priming a pump - filling it with liquid and expelling air in order to get a seal. Not sure if that could apply to the heart though…

@AaronX

I’ve heard this too. The heart isn’t a continuous pump - it fills up, then squeezes using valves to make the blood exit the right direction. If a chamber fills with compressible air, the air won’t leave the chamber when squeezed. In essence the air gets stuck in the chamber, and the pump stops working.

the heart is a pressure pump and will pump air or liquid. in a pressure pump chamber the air will compress more than water so the volume pumped per compression.