Ok, so in the process of doing a little bedside ultrasound teaching, I was scanning this lady in the ER who was being worked up for urosepsis. She had been previously a little hypotensive, apparently, and had gotten some fluid boluses, but was not looking quite comfortable with a BP of about 90 systolic.
So her IVC was pretty normal, about 10-12 mm with visible respiratory variation.
Then I saw something funny in the parasternal views (short axis at the level of the aortic valve)…
Hint: as I scanned around the patient for the possible cause of this, I noted a pressure bag hanging with an empty bag of NS (argh! NS!)… Really empty. I mean, not a drop left in the tubing…
This is iatrogenic air embolism. You can see the bulk of the air is in the RA (left side of the screen), and air bubbles make it into the RV (inflow-outflow) at the top, and some into the PA (curving to the bottom right).
This is not elegant. There is always some air in the drip chamber, so, especially on a pressure bag, an IV bag can’t be allowed to be totally empty…
When we agitate saline to do a bubble study, you get a few seconds of bubble persistence. In this case, two separated examinations about 10 minutes apart revealed little or no change.
Fortunately for the patient, the amount if air is not really enough to cause pulmonary vascular obstruction, as you generally need upwards of 150cc to cause an arrest, and, as we can see by the normal IVC/RV, there was no evidence of even pulmonary hypertension. I left her in the left lateral decubitus position and she remained monitored, recovering uneventfully. I’ll review the management of venous air embolism in the next post!
Here is another clip, a bit of a reverse and hybrid parasternal short axis view but for some reason gave me the best images:
Hate to take you back four years, lol… In the event that there is an iatrogenic embolism, placing the patient in a left side-lying, trendelenburg position, traps the air in the right side of the heart… The air is still trapped, what happens to the air subsequently?
You can try aspirating with a swan, or else just slow absorption… you just need to avoid the big embolism.
thanks for reading!