PaCO2 (mmHg) |
Expected bicarbonate =
24 - ((Baseline PCO2 - Patient's PCO2)/2)
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.
Since the limit of compensation varies between 12 and 20, value less than 20 should be cautiously judged.