A client is brought to the emergency department with suspected diabetic ketoacidosis (DKA). Which finding should the nurse note as being consistent with this diagnosis?

• A. High serum glucose level and low serum bicarbonate level
• B. Low serum glucose level and high serum bicarbonate level
• C. High serum bicarbonate level with low glucose
• D. Normal glucose and normal bicarbonate

Answer: (A)

In DKA, insulin deficiency leads to hyperglycemia and increased ketone production, which causes metabolic acidosis. The acidosis is buffered by bicarbonate, so the serum bicarbonate falls. Therefore the finding of high serum glucose with a low serum bicarbonate best fits DKA. The other patterns don’t show this combination: low glucose with high bicarbonate isn’t DKA, high bicarbonate with low glucose isn’t DKA, and normal values wouldn’t reflect the acidotic state of DKA. In practice, you’d also expect elevated ketones and often an elevated anion gap metabolic acidosis with dehydration.