GI Bleed

[tchristifulli]

Do you think a significant GI bleed or any hypovolemic state would effect your capnography in the early stages?

 

[chaz90]

Absolutely. In uncompensated hypovolemia, decreased blood flow through the lungs and tissues means less CO2 will be carried to the lungs at all. This will lead to a lower EtCO2 value. We're taught to use capnography on these patients as another piece of information to track the severity of their shock. Granted, there may be better ways to do this, but it's certainly interesting in an academic sense and I suppose a trend could show how quickly the patient is deteriorating.

 

[Carlos Danger]

Do you think a significant GI bleed or any hypovolemic state would effect your capnography in the early stages?

No. Compensated shock is just that.....compensated.

 

[chaz90]

I may have had a slight failure in reading comprehension. Yeah, not so much in early, compensated shock. Previous statement remains true for uncompensated shock, which I suppose doesn't really have a lot to do with your original question.

 

[MSDeltaFlt]

Do you think a significant GI bleed or any hypovolemic state would effect your capnography in the early stages?

Since capnography relies on cardiac output, in early stages of hypovolemia capnography would not be effected. In late stages yes, but not early.

 

[Carlos Danger]

I guess it depends on what you mean by "early stages". Early stages of the bleed, before hemodynamics are affected, or early stages of shock, when the bleed has maybe been going on for a while but clinical shock is just becoming evident? I assumed you meant early stages of hypovolemia, before hemodynamics changed.

Personally, I don't see the capnograph as being terribly useful as a diagnostic tool, because there are so many things that can affect it both quantitatively and qualitatively. For trending, certainly it's a useful thing.