CO2 levels - clarification LONG

[Guest guest]

I know this isn't a " hot topic " , but it has peaked my interest again

so I have done some investigating. I was a little " off " on my

explanation yesterday.

The CO2 level that is being tested in a simple blood test is

actually the level of bicarb. When our body produces CO2 it is

dissolved in the blood as bicarb. Then when the blood reaches the

lungs, the bicarb is reconverted into CO2 and released with

breathing.

The kidneys also regulate bicarb by releasing or keeping more when

the body needs to become more or less acidotic.

So, the CO2 level in the Chem 7, is an indirect measurement of CO2.

To get the actual measurement of CO2, you have to have an arterial

blood gas - still a needle stick, but a little more involved since

they have to access an artery.

In Matt's case (when he was 2), his blood work showed him to be

acidotic (low blood pH). He also had a low CO2 level (bicarb). So

they did a bunch of tests to measure certain acids in his blood,

also did a blood gas. They determined that it was metabolic (Since

his blood gas was normal - so the lungs were ok) and started him on

bicarbonate with a diagnosis of Renal Tubular Acidosis. But I am

sure he was acidotic due to his poor nutrition, but the levels

weren't low enough to cause concern.

BOTTOM LINE - If your child is showing low CO2 on the regular blood

panel, it isn't going to tell you much. They might investigate

further and you may want to just try another lab draw. The website

I found said that the values of CO2 can be altered by rough

handling, contamination, and inadequate refrigeration. If the low

value continues, you may want to point out that other kids on this

list have had the same issues and ask if it might be related to

hypoglycemia and poor nutrition?

Beth