High-anion gap hyperchloremic acidosis mimicking diabetic ketoacidosis on initial presentation - Case report

Diabetic ketoacidosis (DKA) often becomes the primary focus and in turn masks a similar serious condition like hyperchloremic metabolic acidosis.

A 20 years old female with type 1 diabetes mellitus presented to the emergency department (ED) with signs and symptoms corresponding to DKA. Initial pH, HCO_3, Na and Cl concentrations were 6.83, 3.6 mmol/l, 143 mmol/l and 122 mmol/l respectively; anion gap 17.4 mmol/l and absent urinary ketones. DKA regime showed no improvement in the measured parameters nor the patient. The diagnosis changed to hyperchloremic high-anion gap acidosis and treatment modifications were made by adding sodium bicarbonate infusion. There was significant improvement in the clinical status of the patient and the calculated parameters.

Hyperchloremic acidosis is associated with a non-anion gap, decrease in plasma bicarbonate and increase in plasma chloride. Rarely, as with this case, it may present with a high-anion gap. The use of bicarbonate therapy has shown improvement in cases of non-anion gap acidosis however there is very little data to support its role in high-anion gap hyperchloremic metabolic acidosis.