Acid-base disorder analysis during diabetic ketoacidosis using the Stewart approach--a case report

This case report presents a 49 year-old female with type 1 diabetes admitted to the intensive care unit with acute respiratory failure and severe diabetic ketoacidosis with an initial measurement of blood glucose level of 1,200 mg L⁻¹, pH 6.78, serum HCO₃ ⁻ 3.2 mmoL L⁻¹ and BE -31.2 mmoL L⁻¹. Analysis of the blood gasometric parameters with the Stewart approach and the traditional Henderson-Hasselbalch concept enabled the discovery of metabolic acidosis caused by unidentified anions (mainly ketons). A treatment protocol with intensive fluid management with 0.9% NaCl, intensive intravenous insulin therapy, and potassium supplementation was administered. Analysis of the gasometric parameters after 12 hours of treatment according to the Stewart approach compared to the Henderson-Hasselbalch concept disclosed that metabolic acidosis caused by the unidentified anions has resolved almost completely and been replaced by metabolic hyperchloremic acidosis. The hyperchloremic acidosis was caused by the intensive fluid resuscitation with 0.9% NaCl, which contains a high chloride load, exceeding the chloride levels observed in human serum. Fluid management with balanced fluids other than saline was continued, together with intravenous insulin infusion, potassium supplementation, and 5% glucose administration. Analysis of this case study revealed the advantages of the Stewart approach to acid base abnormalities compared to the traditional Henderson-Hasselbalch concept. The Stewart approach allows the diagnosis of the exact causes of severe life-threatening metabolic acidosis and the appropriate modification of the therapeutic mangement of patients with diabetic ketoacidosis.