What combination defines diabetic ketoacidosis in terms of glucose, bicarbonate, and pH?

• A. Glucose >250 mg/dL; HCO3 <15 mEq/L; pH <7.2; sodium low; potassium may be normal or slightly elevated
• B. Glucose <80 mg/dL; HCO3 >24; pH >7.45; sodium high
• C. Glucose >400 mg/dL; HCO3 >20; pH >7.35
• D. Glucose 100 mg/dL; HCO3 18; pH 7.32

Answer: (A)

Diabetic ketoacidosis is defined by significant hyperglycemia together with metabolic acidosis from ketone production. The best description shows glucose above 250 mg/dL, bicarbonate below 15 mEq/L, and a pH below 7.2, which together confirm an acidemic state with a substantial metabolic acidosis. The hyponatremia often seen is due to the osmotic effect of high glucose drawing water into the extracellular space, lowering measured sodium, while total body potassium is typically depleted even if serum potassium appears normal or only mildly elevated because insulin deficiency and acidosis push potassium out of cells. The other patterns don’t fit DKA because they either lack the hyperglycemia, show alkalemia or near-normal acid-base status, or present with normal glucose levels despite acidosis, pointing to alternate scenarios.