In pediatric DKA therapy, why is careful potassium replacement essential during insulin therapy?

• A. Insulin drives potassium into cells, causing hypokalemia
• B. Insulin drives potassium out of cells
• C. Potassium has no effect
• D. Potassium should be reduced first

Answer: (A)

Insulin drives potassium into cells, lowering the extracellular potassium concentration. In pediatric DKA, total body potassium is often depleted from dehydration and osmotic losses, even if the initial serum potassium looks normal or high. When insulin is started, the hormone pushes potassium from the bloodstream back into cells, which can cause a rapid and dangerous drop in serum potassium if replacement isn’t given. That’s why careful potassium replacement is essential during insulin therapy—to keep potassium in a safe range as you correct the acidosis and dehydration. Management hinges on the current potassium level: if it’s very low, insulin is held and potassium is given first; if it’s moderately low to normal, insulin is started with potassium supplementation included in IV fluids to maintain a safe range; if potassium is high, you still monitor closely and adjust as insulin takes effect.