I found this online:
CO2 (Carbon Dioxide) - The CO2 level is related to the respiratory exchange of carbon dioxide in the lungs and is part of the bodies buffering system. Generally when used with the other electrolytes, it is a good indicator of acidosis and alkalinity.
Normal Adult Range: 22-32 mEq/L
Optimal Adult Reading: 27
Normal Childrens Range - 20 - 28 mEq/L
Optimal Childrens Reading: 24
Since it is so close to the the "normal" on your sheet I wouldn't worry about it. I just looked at my old bloodwork...
I range from 22-26... I have three old tests and they were all different.
P.S. I e-mailed you but I must have your old address??