Acid Base Balance Review

pH 7.35 - 7.45
PaCO2 35 - 45
HCO3 22 - 28

If the pH is opposite the PaCO2, the problem is Respiratory.
Ex. If the pH is low (7.31), and the PaCO2 is high (47) then the problem is Respiratory Acidosis

If the pH trends with the HCO3, the problem is Metabolic.
Ex. If the pH is low (7.31), and the PaCO2 is normal (37), and the HCO3 is low (20), the problem is Metabolic Acidosis

Ex.
pH 7.50
PaCO2 43
HCO3 45
---> Metabolic Alkalosis, b/c pH trends with the Bicarb

Ex.
pH 7.30 -> Acidosis
PaCO2 43 -> Normal
HCO3 20 -> Low, but trends with the pH
---> Metabolic Acidosis

Thanks for reading.