In addition to insulin and normal saline, which electrolyte is commonly infused in a type 2 diabetic arriving in a hyperglycemic, hyperosmolar, nonketotic state to prevent hypokalemia?

• A. Bicarbonate
• B. Potassium
• C. Calcium
• D. Magnesium

Answer: (B)

Potassium balance is critical when treating a hyperosmolar hyperglycemic state. Giving fluids and starting insulin lowers serum potassium because insulin drives potassium into cells and the patient has ongoing losses from osmotic diuresis. Even if the initial potassium level isn’t low, total body potassium is often depleted, so as insulin is started, serum potassium can fall quickly into a dangerous range. To prevent this, potassium is routinely added to IV fluids so serum potassium stays in a safe range (roughly 3.5–5.0 mEq/L). Bicarbonate isn’t routinely given in this scenario unless there is severe acidosis, and calcium or magnesium aren’t the primary agents to prevent hypokalemia, though deficiencies can be corrected as needed once labs are available. The key point is that insulin and fluid therapy shift potassium into cells and unmask a total body deficit, making potassium replacement essential.