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

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