(In)direct chloride ISE measurements, room for improvement

Abstract

The calculation of the ‘ anion gap ’ (AG) is common practice in the diagnostic workup of patients with a metabolic acidosis. The AG is mostly calculated by subtracting the anions chloride (Cl − ) and bicarbonate (HCO 3 − ) from the cation sodium and aids in differentiating between two types of metabolic acidosis: normalAGacidosis,whereadecreasedHCO 3 − concentrationis compensated increased Cl − , and high AG acidosis, where the concentration of other anions than HCO 3 − Cl − is management, calculation accurate