How could air embolism in the artery ׂ(by syringe) cause heart attack or stroke?

[JameUK]

1) I've been reading very well the article on Wiki air embolism , and it's not clear to me how can a bubble that inserted by syringe to the artery of the arm, reach to the heart or the brain and damage them. the blood flow is just in opposite direction (from the heart to the tissue in case of artery).

2) The article there states: "Gas embolism into an artery is a more serious matter than in a vein, because a gas bubble in an artery may directly stop blood flow to an area fed by the artery."
I don't understand the statement that support in the claim that the artery gas embolism is more serious than in vein. We can say that the same thing can happen with bubble in veins since the bubble can stop the blood flow to an area that drown by the vein, like in case of DVT.

3) It's written there also that in case of vein embolism in the most of the cases it's stopped in the lung. what does it mean "stopped"? does it mean that it goes out by diffusion or it's stuck there?

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[deleted77919]

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[RustedFox]

My first thought when I read the thread title is "how could it not?"

 

[deleted109597]

A few things
We don't answer homework here. That being said, We don't insert things into arteries commonly. Calcium in HF poisoning is literally the only one I know of.
There are reasons venous air can end up in the arteries.
That's not how lung vessels work. That's not how any of this works.

 

[FallingFromSpace]

1) I've been reading very well the article on Wiki air embolism , and it's not clear to me how can a bubble that inserted by syringe to the artery of the arm, reach to the heart or the brain and damage them. the blood flow is just in opposite direction (from the heart to the tissue in case of artery).

2) The article there states: "Gas embolism into an artery is a more serious matter than in a vein, because a gas bubble in an artery may directly stop blood flow to an area fed by the artery."
I don't understand the statement that support in the claim that the artery gas embolism is more serious than in vein. We can say that the same thing can happen with bubble in veins since the bubble can stop the blood flow to an area that drown by the vein, like in case of DVT.

3) It's written there also that in case of vein embolism in the most of the cases it's stopped in the lung. what does it mean "stopped"? does it mean that it goes out by diffusion or it's stuck there?

Air embolism to the brain occurs exclusively in PFOs. Without one, massive venous air embolism will essentially stop circulation as it introduces a compressible gas to the right ventricle, and minor air embolism will go to the vascular bed in the lungs, get trapped and essentially cause a temporary sub clinical PE before resorbing without doing long term damage.

The arterial embolism you are asking about is ischemia in the extremities, as air in an arterial line will go to the capillary beds in your digits. Small amounts are irrelevant if there is adequate collateral flow, large enough amounts can cause severe tissue anoxia like any other embolism.

Again, not the forum for questions related to med school tests.

 

[RustedFox]

Ehhh, I think we're being too hard on him. Its a good physiology question.

 

[JameUK]

First of all, it is not school task or something like that.
I asked it out of curiosity only as someone with an EMT background.
(Moreover, to be honest I even cannot understand how such question can be homework)

Anyway, where can I ask questions about medicine / physiology or whatever in medicine knowledge?
I saw here a lot of forums and then I lost it... maybe you can direct me to the right place / forum to ask such questions which emerge in my mind frequently.

 

[JameUK]

This is not the appropriate venue to ask for help with homework.

You judged me without giving me any opportunity to express my side. It is not homework.

 

[RustedFox]

You judged me without giving me any opportunity to express my side. It is not homework.

Don't get too huffy. We get a lot of posts like this from one-off acounts asking for what is clearly homework help.

 

[JameUK]

A few things
We don't answer homework here. That being said, We don't insert things into arteries commonly. Calcium in HF poisoning is literally the only one I know of.
There are reasons venous air can end up in the arteries.
That's not how lung vessels work. That's not how any of this works.

https://www.ncbi.nlm.nih.gov/pubmed/17986040

 

[JameUK]

Air embolism to the brain occurs exclusively in PFOs. Without one, massive venous air embolism will essentially stop circulation as it introduces a compressible gas to the right ventricle, and minor air embolism will go to the vascular bed in the lungs, get trapped and essentially cause a temporary sub clinical PE before resorbing without doing long term damage.

The arterial embolism you are asking about is ischemia in the extremities, as air in an arterial line will go to the capillary beds in your digits. Small amounts are irrelevant if there is adequate collateral flow, large enough amounts can cause severe tissue anoxia like any other embolism.

Again, not the forum for questions related to med school tests.

Thank you for the answer.
Then in other words you're saying that it can not be (a case of injection air to the artery and this air will reach to the brain (or heart also?) through the artery against the flow direction of the blood.)

 

[Apollyon]

https://www.ncbi.nlm.nih.gov/pubmed/17986040

Dude, arguing with people online from the EMS side (I'm a paramedic, besides an EM doc) is NOT the way to "make friends and influence people".

 

[JameUK]

Dude, arguing with people online from the EMS side (I'm a paramedic, besides an EM doc) is NOT the way to "make friends and influence people".

I respect everybody who tells the truth, politely.
Intellectual honesty isn't considered arguing.

 

[deleted109597]

https://www.ncbi.nlm.nih.gov/pubmed/17986040

Do you know what commonly means? Did you even read the article you posted?

 

[deleted109597]

I respect everybody who tells the truth, politely.
Intellectual honesty isn't considered arguing.

You're not being intellectually honest though. You're being dense, and trying to one up people. If you want to ask questions, by all means. All though a simple google search will answer most of the questions such as yours. http://lmgtfy.com/?q=air+embolism+causing+stroke

 

[e30ftw]

OP you likely would receive less snarky responses if you posted in the EMS/pre-hospital forum.

1) I've been reading very well the article on Wiki air embolism , and it's not clear to me how can a bubble that inserted by syringe to the artery of the arm, reach to the heart or the brain and damage them. the blood flow is just in opposite direction (from the heart to the tissue in case of artery).

Air injected into a peripheral artery ie: radial or dorsalis pedis is very unlikely to cause a stroke or MI.

2) The article there states: "Gas embolism into an artery is a more serious matter than in a vein, because a gas bubble in an artery may directly stop blood flow to an area fed by the artery."
I don't understand the statement that support in the claim that the artery gas embolism is more serious than in vein. We can say that the same thing can happen with bubble in veins since the bubble can stop the blood flow to an area that drown by the vein, like in case of DVT.

The tissue distal to an artery needs the oxygenated blood more than the lung tissue needs deoxygenated blood. Therefore if blood supply is cut off to tissue distal to an arterial source that tissue will suffer ischemia and injury unless there is adequate collateral circulation. Air in a distal artery/arteriole stops blood flow by exerting its "gaseous pressure" on all space around it, including the proximal flow coming from the heart. Have you ever tried to completely compress an exercise ball? Gas occupies space and therefore can block flow.

Air embolus to the lungs can also be serious however it requires a larger volume to cause effect. While around an mL of air in the brain can cause a stroke, around 100ml is required to cause a significant pulmonary infarct when injected venously.

The real risk comes from patients with patent foramen ovale. It is very common for small amounts of air to be injected into a peripheral vein. Anyone who pushes meds often will see tiny patches of air move through the distal tubing. These amounts do not cause injury in most patients however if the patient has a shunt that allows venous air to make it to the arterial circulation a small venous injection can cause stroke. Air goes from the vein to the right atrium, then passes through a shunt to the left atrium, then goes up the aorta (aided by gravity) to the carotid arteries blocking flow in a distal cerebral artery and causing neurovascular ischemia.

3) It's written there also that in case of vein embolism in the most of the cases it's stopped in the lung. what does it mean "stopped"? does it mean that it goes out by diffusion or it's stuck there?

Venous air injected peripherally goes to the lungs, where it is diluted in the vast network of pulmonary arterioles. So your lung arteries (flowing away from the right heart) branch many many times into tiny capillaries, so all the air that was injected venously is split into tiny tiny bits of air that are able to diffuse in the alveoli. Unless >100ml or more was injected, in which case there is a chance of sudden cardiac arrest. By contrast distal peripheral arteries (including those going to the brain) have far fewer bifurcations (splits) and therefore a large amount of the air injected blocks circulation and causes defects. Commonly this is the result of unrecognized CVL placement in the carotid or subclavian artery.

 

[JameUK]

OP you likely would receive less snarky responses if you posted in the EMS/pre-hospital forum.



Air injected into a peripheral artery ie: radial or dorsalis pedis is very unlikely to cause a stroke or MI.



The tissue distal to an artery needs the oxygenated blood more than the lung tissue needs deoxygenated blood. Therefore if blood supply is cut off to tissue distal to an arterial source that tissue will suffer ischemia and injury unless there is adequate collateral circulation. Air in a distal artery/arteriole stops blood flow by exerting its "gaseous pressure" on all space around it, including the proximal flow coming from the heart. Have you ever tried to completely compress an exercise ball? Gas occupies space and therefore can block flow.

Air embolus to the lungs can also be serious however it requires a larger volume to cause effect. While around an mL of air in the brain can cause a stroke, around 100ml is required to cause a significant pulmonary infarct when injected venously.

The real risk comes from patients with patent foramen ovale. It is very common for small amounts of air to be injected into a peripheral vein. Anyone who pushes meds often will see tiny patches of air move through the distal tubing. These amounts do not cause injury in most patients however if the patient has a shunt that allows venous air to make it to the arterial circulation a small venous injection can cause stroke. Air goes from the vein to the right atrium, then passes through a shunt to the left atrium, then goes up the aorta (aided by gravity) to the carotid arteries blocking flow in a distal cerebral artery and causing neurovascular ischemia.



Venous air injected peripherally goes to the lungs, where it is diluted in the vast network of pulmonary arterioles. So your lung arteries (flowing away from the right heart) branch many many times into tiny capillaries, so all the air that was injected venously is split into tiny tiny bits of air that are able to diffuse in the alveoli. Unless >100ml or more was injected, in which case there is a chance of sudden cardiac arrest. By contrast distal peripheral arteries (including those going to the brain) have far fewer bifurcations (splits) and therefore a large amount of the air injected blocks circulation and causes defects. Commonly this is the result of unrecognized CVL placement in the carotid or subclavian artery.

Thank you for the answer. I appreciate it.
The conclusion based on your answer, is:
1) Air injected into a peripheral artery ie: radial or dorsalis pedis is very unlikely to cause a stroke or MI, but it can damage the tissues in the area of the injection or distal to that place.
2) the bubbles don't 'get back' against the blood flow direction.
3) those small bubbles which enter through the line or the syringe are not significant* and they are normally broken into small bits which able to get out by diffusion. (*unless it's a patient with shunt, it could be dangerous. here I would like to add that the one of the three classifications of an arterial air embolism is "paradoxical embolization" which includes also shunt, as written in the article of UTD)

 

[DocEspana]

Thank you for the answer. I appreciate it.
The conclusion based on your answer, is:
1) Air injected into a peripheral artery ie: radial or dorsalis pedis is very unlikely to cause a stroke or MI, but it can damage the tissues in the area of the injection or distal to that place.
2) the bubbles don't 'get back' against the blood flow direction.
3) those small bubbles which enter through the line or the syringe are not significant* and they are normally broken into small bits which able to get out by diffusion. (*unless it's a patient with shunt, it could be dangerous. here I would like to add that the one of the three classifications of an arterial air embolism is "paradoxical embolization" which includes also shunt, as written in the article of UTD)

When you lay it out like that it still sort of seems like homework.

 

[Psai]

https://www.ncbi.nlm.nih.gov/pubmed/17986040

Jesus christ you're annoying

 

[BAM!]

First of all, it is not school task or something like that.
I asked it out of curiosity only as someone with an EMT background.
(Moreover, to be honest I even cannot understand how such question can be homework)

Anyway, where can I ask questions about medicine / physiology or whatever in medicine knowledge?
I saw here a lot of forums and then I lost it... maybe you can direct me to the right place / forum to ask such questions which emerge in my mind frequently.

Ask them at www.quora.com

 

[jwk]

Thank you for the answer. I appreciate it.
The conclusion based on your answer, is:
1) Air injected into a peripheral artery ie: radial or dorsalis pedis is very unlikely to cause a stroke or MI, but it can damage the tissues in the area of the injection or distal to that place.
2) the bubbles don't 'get back' against the blood flow direction.
3) those small bubbles which enter through the line or the syringe are not significant* and they are normally broken into small bits which able to get out by diffusion. (*unless it's a patient with shunt, it could be dangerous. here I would like to add that the one of the three classifications of an arterial air embolism is "paradoxical embolization" which includes also shunt, as written in the article of UTD)

I'll disagree on one point - it most certainly is possible for bubbles/air to go against arterial flow. Arterial line setups are pressurized to 250-300mmHg. That's more than enough pressure to drive bubbles retrograde up an artery.