How much air has to be in a syringe and then injected into the vein before the heart loses it’s prime with a big shot of air?
Sorry this may have been done before, but I didn’t look through the hundreds of threads.
The problem is more with the capiliaries than the heart. A very small bubble in the right place (the brain, the lungs, the capiliaries feeding the heart) can cause tremendous damage and death.
And in general 5ml of air is enough to cause concern, although it is unlikely to cause death or serious injury in an average healthy adult. I am not sure what the minimum dose would be to guarantee death, but I would guess that 10-15ml would probably do it most of the time.
I almost hate to ask, but why do you want to know?
Here’s a previous thread on the topic:
air embolism
It gave me a scare to see the odd bubble in the tube for my girlfriend’s drip after she’d given birth, the nurse assured me that a few mm’s long wasn’t anything to worry about :eek:
Because I’m curious.
and I always knew that if the air bubble was large enough, it will lose it’s prime. Just not how large.
I can’t think of any reason why there should be bubbles in an IV line. In my nursing days I wouldn’t have allowed it and I was a mere Psych Nurse.
Once you have everything set up it a sealed system and if you have the fluids running with no air in the tubes there is no way for air to enter.
I can’t find the thread on this from before, but I had a big air bubble in a line when I went in for nasal surgery. I saw the bubble coming, and it was close to 2 frickin feet long! I cinched the line and stared wild-eyed at the doctor that came over. He just looked at me and said “Only in the movies…I think you need something to relax you.” And he gave me a shot of something that sure enough relaxed me. I watched that whole 2 feet of bubble go right in me. Freaky.
-Tcat
I had this happen to me in the hospital. The bubble in my IV wasn’t two feet long but long enough (maybe 6 inches…been awhile). I totally freaked and was madly mashing the call button for a nurse. I was getting ready to rip the line from my arm when the nurse came in and I frantically pointed at the bubble while babbling incoherently about it killing me. She told me not to worry. Her explanation was that the rate at which the bubble moved and the thinness of the line in my arm meant that the passing blood easily absorbed the air as it went in so no bubbles in my arm.
Needless to say I was dubious but since I am hear and writing this it would seem the nurse was correct. This is not to say bubbles in your blood stream are trivial but it seems coming down an IV line they are not an issue. That said I am sure I would still stare wide eyed at another one coming down my line should I be in that position again. They really should explain this to patients…save everyone some trouble.
Perhaps not allowed in your care, but from my own experience, and apparently that of the other posters previous to me, it seems to happen quite a bit.
I had the same panic as described by the others. Same response from the nurses too.
As long as it is going into a peripheral vein, it would take a lot of air to create a problem since, as has been stated, the air will become dissolved in the blood before it can reach anywhere it can cause a problem. I have been told that you could flush all the air from an IV line (about 60 mL) into a patient and there would be no adverse sequelae. With extremely large boluses of air, you need to worry about it getting trapped in the heart and compromising cardiac output, or causing a pulmonary embolus. I do not think it would get to the brain without a cardiac defect, as the lungs make a pretty good filter.
If the air is injected into a central vein, it takes much less to cause problems. That is why there is always a filter on those lines. If the air gets into a carotid artery, it can easily cause a stroke–that is a major complication of injuries to those vessel.
I’ve seen a few inches go into little kitties and puppies with no adverse effects. I asked the vet and he said that the air circulates to the lungs and “fFFFfffft”
Really…that’s what he said…“fFFFfffft”
And he wore a white coat, so he must’ve been right.
There is a test that is designed to look for a ‘patent foramen ovale’. That is, a heart defect with a poorly closed hole between your right and left atria (top chambers of the heart). While looking with an ultrasound probe, a tube of saline is shaken up so that it has a lot of little bubbles and is injected quickly into a vein. As the bubbles travel through the vein to the right atrium, they can be seen passing into the left atrium if there is a PFO. Like xbuckeye says, the bubbles are absorbed by the lungs. No big whoop.
The forensic literature states that you need 200 ml on the venous side to cause death. 200 ml is a LOT. I don’t know how they came up with this number.
When that huge an amount of air enters the right ventricle, it churns, producing a frothy mass of tiny bubbles. The mass of bubbles obstructs the passage of blood. Since blood is pretty good at absorbing oxygen from air, and nitrogen seems to wander through the body at will, it has to be a heckuva large mass of bubbles.
I would be surprised if the air in your IV line is even one cc at a time.
Air on the arterial side can kill you in much smaller amounts. I’ve got a photograph from a mentor’s collection of a heart from an autopsy with air bubbles in the left anterior descending coronary artery. Guy had been knifed and he had a run of bad luck culminating in air on the arterial side.
But it’s awfully hard to get air into the arteries, so don’t even think about it. Even if you had an A-line (like an IV but into an artery), any air which went into the blood would follow the pounding rush away from the heart, not towards it. You’d be fine.
to which diggleblop, the OP of this thread, contributed more than one post.
But to be fair what he states in that thread what has become the question for this current OP.