In DKA, why is potassium often normal or elevated at presentation despite total body potassium depletion?

• A. Insulin deficiency and acidosis promote potassium shift from cells to extracellular space; with insulin therapy and correction of acidosis, potassium can drop
• B. Poor intake increases potassium
• C. Ketone bodies bind potassium
• D. Potassium loss in urine is minimal

Answer: (A)

Potassium balance in DKA is about where potassium sits inside vs outside cells, not just how much is in the body. When insulin is deficient and acidosis is present, potassium is nudged out of cells into the extracellular space to help balance charges. This pushes the blood potassium level up or keeps it normal even though the total body potassium is already depleted from losses in urine (and sometimes gut losses) due to osmotic diuresis and vomiting. When therapy starts—insulin is given and acidosis corrects—potassium moves back into cells, and the serum level can fall, potentially becoming dangerously low if potassium isn’t replenished.

The other options don’t fit because poor intake alone doesn’t explain a normal or high serum potassium, ketone bodies don’t meaningfully bind potassium to raise serum levels, and in DKA there are significant urinary potassium losses due to osmotic diuresis, not minimal losses.