PaCO2 (mmHg) |
Expected bicarbonate = 24 + ((Patient's PCO2 - Baseline PCO2)/2.5)
NOTE: Baseline PCO2 default should be 40.
Interpretation: If patient's bicarb is higher than expected, a superimposed metabolic alkalosis is present. If it is lower, a superimposed metabolic acidosis is present.
Limit of compensation: 45. So any result (expected bicarbonate) higher than 32 should be converted to 45.
Reference:
Doyle DJ. A Synopsis of Acid-Base Analysis. http://acidbase.homestead.com/ABG_Analysis_Rev_2.0.pdf. Update Jan 2006. Last assessed June 2013