What does anion gap metabolic acidosis indicate in the context of DKA?

• A. Accumulation of ketoacids (acetoacetate and beta hydroxybutyrate) due to insulin deficiency and lipolysis
• B. Lactic acidosis due to hypoperfusion
• C. Hyperchloremic acidosis
• D. Metabolic alkalosis

Answer: (A)

In DKA, the lack of insulin leads to rampant lipolysis and ketogenesis, so the body makes a lot of ketoacids. The major acids produced are acetoacetate and beta-hydroxybutyrate. As these accumulate, they donate hydrogen ions and are buffered by bicarbonate, which gets used up and the measured anion gap rises. That’s why this situation shows a high anion gap metabolic acidosis: it’s the ketone bodies causing the excess unmeasured anions.

Lactic acidosis due to poor perfusion can occur but isn’t the primary driver in classic DKA; hyperchloremic acidosis would produce a normal (not elevated) anion gap, and metabolic alkalosis is the opposite disturbance.