Introduction to Respiratory Care/Arterial blood gases

Many methods exist to guide the interpretation of the ABG.

Step 1: Henderseon-Hasselbach equation
[H+] = 24(PaCO2) / [HCO3-] If the pH and the [H+] are inconsistent, the ABG is probably not valid.

Is there alkalemia of acidemia present?
pH < 7.35 acidemia pH > 7.45 alkalemia
 * This is usually the primary disorder
 * You will need to check the PaCO2, HCO3- and anion gap
 * An acidosis or alkalosis may be present even if the pH is in the normal range (7.35 – 7.45)