During DKA treatment, which electrolyte is at risk of dropping due to insulin therapy?

• A. Hyperkalemia
• B. Hypokalemia
• C. Hypercalcemia
• D. Hypomagnesemia

Answer: (B)

Potassium is the electrolyte most at risk of dropping during insulin therapy in DKA. When insulin is given and acidosis resolves, potassium shifts from the extracellular space into cells via activation of the Na+/K+-ATPase pump. Although many patients with DKA may have a normal or even high serum potassium at presentation due to insulin deficiency and acidosis, their total body potassium is usually depleted from diuresis and insults of ketosis. As insulin therapy starts and potassium moves back into cells, serum potassium can fall rapidly, risking clinically significant hypokalemia if not monitored and replaced.

That’s why potassium management is central to DKA treatment: check potassium before starting insulin, hold or adjust insulin if potassium is very low, and replace potassium to keep the serum level in a safe range as treatment continues. Hyperkalemia would be less likely to persist once insulin is given, and while magnesium or calcium issues can occur, the immediate, best-supported risk during insulin therapy is a drop in potassium.