Capnography waveform and chest compressions.

Aidey

Aidey

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I know what chest compressions can produce oscillations on the capnography waveform. Does anyone know if these CPR oscillations can happen with an esophageal intubation?

Short story: Traumatic arrest with multisystem trauma, inital ETCO2 of 50 mm/hg, quickly droped to 8 mm/hg and stayed there. There were waveform oscillations with CPR and also a "normal" (albeit very squat) waveform when there were no chest compressions. 20+ minute downtime on the PT.
 
Short answer: no

This patient was just dead, so not producing CO2 to register. If the tube was esophageal you would very quickly not get any waveform at all (you may get an initial spurious trace from carbonated beverages in the stomach, but that only lasts a ventilation or two.

You were obviously in the trachea with the tube and the CPR was producing some co2 but clearly the patient is dead. Did you place the tube? Don't sweat it if you did, you just can't resurrect a corpse.
 
I did place the tube. I don't doubt the placement (well maybe just a tiny bit). I'm pretty sure a large amount of his blood volume was in his chest also.

The question came from a discussion with some other people, one of whom claimed such a low CO2 could only be from an esophageal tube. I didn't think you would get oscillations with an esophageal tube, but I wasn't sure, and several hours on google got me no where, so I figured I would ask here.
 
The waveform is the important part, even if it looks squat.

Tell the window licker that carbon dioxide is a byproduct of cellular metabolism carried back to the lungs by blood, and after 20+minutes of traumatic arrest there's often not any blood left in the vessels to carry that byproduct back to the lungs for exhalation. ETCO2 of less than 10mmHG is considered to be a reliable sign of death.
 
Having run several codes with etco2 waveforms to watch I can tell you that the waveforms will be quite small, usually less than 10 mm/hg. The EtCo2 measures the carbon dioxide exiting the lungs and when doing CPR the air exchange is so poor that the wave form will not be as high as you might normally see.

Tell your buddy to go back to school and take an inservice on capnography rather than capnometry.

Check www.Capnography.com
 
ArcticKat said:
Having run several codes with etco2 waveforms to watch I can tell you that the waveforms will be quite small, usually less than 10 mm/hg. The EtCo2 measures the carbon dioxide exiting the lungs and when doing CPR the air exchange is so poor that the wave form will not be as high as you might normally see.

Tell your buddy to go back to school and take an inservice on capnography rather than capnometry.

Check www.Capnography.com
Click to expand...

The oscillation waveforms were quite small, but the "real" waveforms weren't any taller, just longer, which is part of why the person said it must be esophageal. Their assumption was the actual breaths should produce a bigger waveform. I think the real disconnect was a disagreement about how dead the patient was, which was deader than that person thought they should be.
 
Initial CO2 of 50mm/hg, dropped rapidly to 8mm/hg...kinda sounds like what they say can happen in esophageal intubations doesn't it? (Yeah, I know I'm defending my coworker a bit, but I can see how he came to the conclusion he did).

I've spent time on capnography.com, thanks though. Honestly that website annoys the crap out of me. There is good info, but it is disorganized and poorly laid out with only one or two examples of each waveform.
 
Esophageal intubation will just give a value of 0. That's the benefit of it there-instant feedback of wrong placement. a value of 8 with that downtime has been normal for me.


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- Sent from my electronic overbearing life controller
 
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