What does air do to your heart?

March 15, 2005 7:12 PM

So what happens when you accidentally inject 2 mLs of air directly into a vein via an IV?

It was a complete accident about 6 years ago. This was a midline IV. There were some immediate side effects, but nothing permanent that I know of. Now I am wondering if there could have been permanent damage.

posted by bh to health (12 comments total)

I found this article a while back while milling around on google... It says it takes 200cc's to be immediately fatal. From scuba diving, I can tell you that if air (which is mostly nitrogen) behaves like pure nitrogen then it has almost guaranteably dissolved into your bloodstream. If you haven't noticed any damage by now there will almost certainly never be any. But then again... Sometimes these questions are better left for doctors.
posted by mervin_shnegwood at 7:31 PM on March 15, 2005

By midline, do you mean central line? What vein was the canula in? And what symptoms are you having that you're attributing to this, 6 years later?
posted by gramcracker at 7:33 PM on March 15, 2005

I heard that id you get enough air in there it will go into your heart. Your heart will start pumping the air instead of the liquid and because it compresses so well your blood stops dead.

Not sure if that's true.
posted by Napierzaza at 7:47 PM on March 15, 2005

I have seen plenty of air bubbles enter my system through the many IVs I have had over the last few years. The nurses and doctors both said not to worry about it. I don't know if any of those bubbles were 2 mLs, but then, 2 mLs isn't a very large volume.
posted by mischief at 7:55 PM on March 15, 2005

I really wouldn't worry about it if it was only 2 ml. The only way there would be long-term side effects would be if the patient suffered a heart attack. And I've seen literature which describes an injection of 150ml as "near fatal", so you're not even in the ballpark.
posted by Justinian at 8:36 PM on March 15, 2005

The answer to your question is nothing happens.

With venous air emboli, case reports have found the lethal volume to be on the order of 200-300 mL. One study reports that 3-8 mL/kg is enough to cause acute right ventricular outflow obstruction and death. This is the primary cause of sudden death in patients with major venous air emboli. Essentially, the air gets pumped into the pulmonary arteries, and obstructs further flow of deoxygenated blood into the lungs.

At intermediate doses, which don't cause your blood to essentially stop flowing, the gas in in the pulmonary arteries directly causes injury to the endothelial cells on the surface of one's capillaries, which starts a cascade that can lead to pulmonary edema, which is also a major concern and potentially fatal if not managed appropriately.

I'd say chances are, even if you suffer from a major, potentially fatal venous gas embolism (likely requiring a stay in the intensive care unit), if you survive and make it through the initial critical stage, you won't suffer any real consequences.
posted by drpynchon at 9:52 PM on March 15, 2005

Thanks for the answers.

I had an IV in my arm for a few months while I was on a heavy duty antibiotic. I neglected to fill the syringe with heparin one day, and instead shot 2 mLs of air into myself. I always thought the immediate effects (very high heart rate, dropping blood pressure for a few minutes) were mental, but I've never gotten a straight answer on it.

I was too far away to bother calling 911, so I just sat it out. It was a very strange feeling.

Oh, and I didn't mention it to the doctor because it was hard enough to convince him that I could take care of things at home.
posted by bh at 1:42 AM on March 16, 2005

Ha! I knew all those hours spent reading detective fiction would come in useful sooner or later.

In Dorothy L. Sayers's Unnatural Death, the murderer uses precisely this modus operandi, injecting an air bubble into a main artery. The beauty of this method is that there are no obviously suspicious circumstances; it just looks as though the victim has suffered sudden heart failure. Sayers describes it very plausibly, but the consensus of opinion seems to be that it would be a very risky method of murder: the air bubble probably wouldn't be big enough to have any effect, and even if it did, there is no guarantee that it would actually be fatal. The comments in this thread appear to confirm this.

Sayers based the novel on the case of May Daniels, a nurse who was found dead with an empty hypodermic syringe lying beside her. The case was never solved, and the identity of Nurse Daniels' murderer remains a mystery to this day.
posted by verstegan at 2:21 AM on March 16, 2005

I'll add to the "nothing much" comments. We nurses can often be seen tapping on IV lines to removes air bubbles, but it's because the bubbles can impede flow, not hurt you. dr pynchon's answer is very complete. Remember that a cup holds 240cc, and picture the volume of air that would be needed to cause an air embolus.
posted by reflecked at 3:30 AM on March 16, 2005

From a number of years of going to a chemo infusion suite, a couple of CC's of air injected into your veins is not a worry at all - it will get removed at the lungs. Air injected to an artery, however is highly dangerous and can lead to heart problems and stroke. (this all from the nice nurses at beth israel medical center here in nyc)
posted by jba at 8:29 AM on March 16, 2005

Can you die from shooting up champagne?
posted by Mean Mr. Bucket at 10:32 AM on March 16, 2005

This is actually done in at least one place that I know of - the echocardiography suite. The little air bubbles travel from the peripheral vein to the right atrium and thence right ventricle of the heart, where they can be seen bubbling about. If there is a right-to-left shunt within the heart (i.e. a septal defect or patent foramen ovale), the bubbles can be seen to cross over, and this is how such shunts are detected. The usual volume of air injected is 5cc.

The air then travels to the lungs, where it lodges in the pulmonary capillaries and quickly diffuses out into the airways.

Your symptoms were due to anxiety, not the bubbles.

Air into a peripheral artery is a different story, and has an unhappy ending.
posted by ikkyu2 at 3:45 PM on March 16, 2005