CO2 and hydration

ERNurse752, RN · Jun 13, 2007

Low serum CO2 means they're acidotic. Could be lots of reasons though.

GilaRRT · Jun 13, 2007

I agree. A low CO2 can indicate a metabolic acidosis with respiratory compensation. However, one must be careful with generalizations. I would never assume all people with a low CO2 would be dehydrated.

phiposurde · Jun 13, 2007

Recently a fellow nurse told me that if someone's CO2 is low it means they are dehydrated. I had never heard this before and was wondering if any of you had, and if so, how the two are related.

** On an ABG the CO2 is related to ventillation. either you hypoventillate and it increase or you hyper ventillate and it decrease. I don't really see how you do a direct correlation between dehydration and ventillation. I think there much better other indicator. Turgor, the tongue, electrolytes. Maybe in very bad dehydration we are getting in acid/base balance abnormality therefore compensation is require.

GilaRRT · Jun 13, 2007

I do not think you can make a direct correlation between dehydration and CO2 levels. However, dehydration can lead to hypoperfusion and lactic acid production. A degree of metabolic acidosis can be expected in people who are dehydrated. This is especially true with carpet commandos. In addition, with decreased fluid levels comes decreased renal perfusion and the retention of hydrogen ions, leading to a metabolic acidosis. I know many clinicians will utilize the venous CO2 in the SMA-12 or SMA-7 as supporting evidence for a patient they suspect is dehydrated.

phiposurde · Jun 13, 2007

I do not think you can make a direct correlation between dehydration and CO2 levels. However, dehydration can lead to hypoperfusion and lactic acid production. A degree of metabolic acidosis can be expected in people who are dehydrated. This is especially true with carpet commandos. In addition, with decreased fluid levels comes decreased renal perfusion and the retention of hydrogen ions, leading to a metabolic acidosis. I know many clinicians will utilize the venous CO2 in the SMA-12 or SMA-7 as supporting evidence for a patient they suspect is dehydrated.

*** That far out I would call that more a hypovolemic shock then dehydration. In that case, I would use base excess and anion gap more the co2. My 2 cents!8)

GilaRRT · Jun 13, 2007

Is dehydration not hypovolemic shock?

phiposurde · Jun 14, 2007

Is infection equal sepsis??8) The question was that dehydration is related to co2 content. My point is that for that to happen alot of change have to happen to the acid/base balance to create a change therefore we enter in an other category and should be threated other wise as well. If i have someone that is alittle bit dry cause I came back from a hike and didn't drink much. I don't think I would consider doing an ABG. But if the same person show sign of change in there vitals enough to have a hYpovulemic shock, my nursing would be diffrent. I would pay more attention to that person. But just like sepsis, sepsis shock. every thing as name cause they are more advance on the continum. No ?

Is dehydration not hypovolemic shock?

GilaRRT · Jun 14, 2007

I do understand your point. However, you need not do an ABG to obtain a venous CO2. This vaue shows up on your average everyday SMA-7 or SMA-12. (BMP/CMP) So, if I had a dehydrated patient (especially a kiddo), I would not be suprised to see a low venous CO2. Good discussion by the way.

phiposurde · Jun 14, 2007

I do understand your point. However, you need not do an ABG to obtain a venous CO2. This vaue shows up on your average everyday SMA-7 or SMA-12. (BMP/CMP) So, if I had a dehydrated patient (especially a kiddo), I would not be suprised to see a low venous CO2. Good discussion by the way.

**** Made your point. To celebrate it, next patient I have with dehydration I will look at the SMA-7 AND the CO2!!

cardsRN · Jun 14, 2007

just popping in to say go team! great discussion and way to keep it civil! we need more of this kind of spirit of debate on these boards! :w00t:

phiposurde · Jun 14, 2007

I do understand your point. However, you need not do an ABG to obtain a venous CO2. This vaue shows up on your average everyday SMA-7 or SMA-12. (BMP/CMP) So, if I had a dehydrated patient (especially a kiddo), I would not be suprised to see a low venous CO2. Good discussion by the way.

*** so in order to have a real win/win situation . When would it be more a shock and more " dehydration"? also, when in dehydration would the level co2 start changing( mild, moderate, severe)??