In a 23-year-old with new-onset type 1 diabetes and severe dehydration with potassium 3.1 mEq/L, after initial fluids what is the next step in management?

• A. Oxygen therapy
• B. Administration of dextrose
• C. Administration of insulin
• D. Administration of potassium chloride

Answer: (D)

Potassium management is the critical next step in diabetic ketoacidosis when serum potassium is low. In DKA, total body potassium is depleted from urinary losses and shifts out of cells during acidosis and insulin deficiency, even if the initial potassium reading is normal. Here, potassium is 3.1 mEq/L, which is below the level at which insulin can be safely started. The correct move after fluids is to replace potassium with potassium chloride to raise serum potassium, aiming for at least 3.3 mEq/L before or while starting insulin therapy. This prevents the dangerous drop in potassium that insulin treatment can provoke.

Oxygen therapy isn’t indicated here unless there’s hypoxemia. Dextrose-containing fluids aren’t needed yet because insulin hasn’t been begun, and the priority is correcting the hypokalemia. Starting insulin now would worsen the potassium deficit, which is why potassium replacement takes precedence. After potassium is stabilized (ideally ≥3.3 mEq/L), insulin can be initiated and potassium continued to maintain a safe range, typically 4–5 mEq/L.