Question of the Day

Think of an increased anion gap (AG) with renal failure, ethylene glycol toxicity, lactic acidosis from grain overload or strenuous exercise, and diabetic ketoacidosis.

The AG is an assessment of acid-base status and evaluates unmeasured anions such as ketones, lactate, uremic metabolites, and toxins (e.g., ethylene glycol).

Anion gap = (Na⁺ + K⁺) – (HCO_3^– + Cl^–)

If venous blood gas analysis is unavailable substitute TCO₂ for HCO_3^–.

Here is more information from Cornell’s eClinPath website about measurement of the anion gap.