Hello all, I am currently an AEMT student just starting on IVs, and I have a couple questions about air embolisms. If you’re starting an IV, and they are not bleeding very much and blood doesn’t fully fill up the catheter all the way, even if you flush the extension set full there’s still some air in the catheter between the blood and the saline. How does that not cause an embolism? Also, if you miss the vein, or inadvertently go all the way through the vein and attempt to inject saline (which really shouldn’t happen if you pull back to make sure you have blood, but if it does) I assume there no way that could cause an air embolism since it’s not in the vein, correct? And lastly, how long would it take for an air embolism from an IV to show symptoms and/or lead to death? This is just a couple things on my mind that I thought I’d ask about.
Air embolism questions
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Takes at least 50 ccs to create an issue.
Your Instructor should have covered all this.
Your Instructor should have covered all this.
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The slightly longer answer is that those small bubbles do create an air embolism. However they ultimately get trapped by the lungs and dissipate quickly as we breathe. In short, they're not a problem. We actually do bubble studies where we agitate saline very vigorously and inject the aerated saline rapidly into the bloodstream. It's so we can see how the blood flows in the heart and if there are any small open ducts in the heart and vasculature. Those bubbles are very visible on ultrasound and the gas quickly gets absorbed in the blood so... there's no problem with those either. It takes a LOT (about 50 mL) of air to basically make the heart not pump fluid. That's not to say we shouldn't actively try to minimize the amount of air in the IV line, but we shouldn't be so frightened about small bubbles that we expend a significant amount of time purging all air. Just don't spike a bag, fill the chamber and attach an unflooded line to a patient and run it all in... 20 mL or so of air as a bolus isn't exactly good for the patient.
I had a nurse do that in the hospital last year, when my BP dropped and freaked them out (80/40 resting down to 60/30).
She started a new site and didn't flush the line, It felt weird going in, and I saw why just as the last 2 or 3 inches of air went it, I yelled and she started swearing, but after 20 seconds or so I didn't feel anything anymore, and the hospitalist said that the 15-20mL wouldn't hurt me much.
It caused a short run of V-Tach (7 PVCs) and I felt them. A little chest pain, for about 1 minute, But that was it
She started a new site and didn't flush the line, It felt weird going in, and I saw why just as the last 2 or 3 inches of air went it, I yelled and she started swearing, but after 20 seconds or so I didn't feel anything anymore, and the hospitalist said that the 15-20mL wouldn't hurt me much.
It caused a short run of V-Tach (7 PVCs) and I felt them. A little chest pain, for about 1 minute, But that was it