Why must potassium be monitored closely during DKA treatment?

• A. Potassium is not affected by insulin therapy
• B. Potassium levels rise with insulin
• C. Potassium shifts out of cells with insulin therapy
• D. Potassium shifts into cells with insulin therapy; total body potassium is depleted

Answer: (D)

Key idea: insulin therapy during DKA moves potassium from the extracellular space into cells, and overall potassium stores in the body are actually depleted by prior diuresis and electrolyte losses. Because insulin lowers serum potassium quickly, it’s essential to monitor potassium closely and replace as needed to prevent hypokalemia. At presentation, a patient may have normal or high serum potassium despite depleted total body potassium; starting insulin can cause a rapid drop in serum potassium, so potassium management is a critical part of DKA treatment. If potassium is very low, you hold insulin and give potassium first; if it’s moderately low, you add potassium with IV fluids; if it’s high, you still monitor and plan for eventual replacement as insulin is continued.