During treatment of diabetic ketoacidosis or hyperglycemic hyperosmolar state, which electrolyte must be monitored and possibly supplemented to prevent hypokalemia?

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

Answer: (B)

Potassium balance is the key issue when treating diabetic ketoacidosis or hyperglycemic hyperosmolar state. Although total body potassium is often depleted in these conditions due to osmotic diuresis and losses, serum potassium may initially be normal or high because of acidosis and insulin deficiency. Once insulin is given and acidosis resolves, potassium shifts back into cells, which can cause a rapid drop in serum potassium and dangerous hypokalemia if not monitored and replaced.

Therefore, potassium must be closely watched and supplemented as needed to keep the serum level in a safe range. If the serum potassium is very low (below about 3.3 mEq/L), insulin is withheld and potassium is given first until the level rises above that threshold. If the potassium is in the intermediate range (roughly 3.3 to 5.0 mEq/L), insulin therapy is started but potassium is simultaneously provided to prevent a fall. If potassium is high (above about 5.0 mEq/L), potassium supplementation is avoided while continuing to monitor.

This approach prevents hypokalemia, which can lead to life-threatening cardiac and neuromuscular complications, and ensures potassium remains available for essential cellular functions during treatment.