End tidal co2 in carbon monoxide poisonings

[sethgreely]

Has anyone put capnography on a carbon monoxide poisoning? I had to write a paper about it back in medic school, and the all knowing internet had nothing on it. I would assume it would read either normal, or high, but there is no studies on it (that i know of).

thanks for the input!

[paramedicmike]

If you had to write a paper on it back in medic school, about what did you write? Seems like your prior research would be a good place to start.

[Just Plain Ruff]

I would first start with your paper you wrote way back when, take a look at the sources you used and then go out and see if those sources have been updated...

Another good resource to discuss this with would be a respiratory therapist at a hospital that does Hyperbaric chambers.

Here's an interesting study going on http://www.clinicaltrials.gov/ct2/show/NCT01859156

And some good links in the comments on this facebook thread. https://www.facebook.com/sincitymedic/posts/501529653215350

But that's all the work I'm going to do for you, I was able to find these two sites in less than 15 seconds of searching via google.

But in my searching I found this really neat book on International EMS - http://books.google.com/books?id=MtBlevPHBCgC&pg=PA262&lpg=PA262&dq=ETC02+and+carbon+monoxide+poisoning&source=bl&ots=MNjJ2I3XST&sig=lCGV_xGx-3xCVGuj1dND6iiH4JI&hl=en&sa=X&ei=efOYU8XkBNekyAT084CIBg&ved=0CGsQ6AEwCTgK#v=onepage&q=ETC02%20and%20carbon%20monoxide%20poisoning&f=false

YOu have to read it online but it's a cool book.

[systemet]

Short answer, the PETCO2 may be high, normal or low. It's going to reflect respiratory compensation for an underlying metabolic acidosis, but is also dependent upon hemodynamics and pulmonary function.

Changes in PETCO2 and PaCO2 are going to be very non-specific and insensitive in CO poisoning. You can expect PaCO2 to decrease in the early stages of poisoning, as the patient hyperventilates to create a compensatory secondary respiratory alkalosis. As they become obtunded, the PaCO2 is going to rise, and they'll develop a mixed acidosis.

Whether these changes in PaCO2 will be reflected in the PETCO2 will depend upon hemodynamics (i.e. pulmonary perfusion), and lung function.