Delta Gap

Wrenn K. The delta (delta) gap: an approach to mixed acid-base disorders. Defines the delta gap as ΔAG − ΔHCO₃⁻: significantly positive (> +6) usually means a concurrent metabolic alkalosis, significantly negative (< −6) a concurrent hyperchloraemic acidosis.

Rastegar A. Use of the ΔAG/ΔHCO₃⁻ ratio in the diagnosis of mixed acid-base disorders. The ratio is expected to be close to unity when a strong acid is added to plasma, but has a wide range in individual patients, so it should be used cautiously to diagnose a mixed disorder (shown here for information only).

Kraut JA, Madias NE. Treatment of acute metabolic acidosis: a pathophysiologic approach. Calculating the serum anion gap and its change from baseline helps detect organic acidoses. The anion gap itself (and the albumin correction) is the one from the Anion Gap calculator.