Which laboratory value in a patient with diabetic ketoacidosis on an insulin infusion needs to be reported promptly?

Which laboratory value in a patient with diabetic ketoacidosis on an insulin infusion needs to be reported promptly?

• A. Calcium 9.2 mg/dL
• B. Sodium 137 mEq/L
• C. Potassium 3.1 mEq/L
• D. Serum osmolality 288 mOsm/kg H2O

Answer: (C)

Potassium balance is the critical issue when treating diabetic ketoacidosis with insulin. In DKA, total body potassium is depleted from urinary losses, even if the blood potassium appears normal or high at presentation because of acidosis and insulin deficiency. When insulin infusion is started, potassium shifts into cells, which can cause a rapid and dangerous drop in serum potassium—hypokalemia. A potassium level of 3.1 mEq/L is clearly below the safe range and needs immediate attention. This value guides urgent management: hold or adjust insulin and begin potassium repletion to raise the serum level above about 3.3–3.5 mEq/L before continuing aggressive insulin therapy, to prevent life-threatening arrhythmias and muscle weakness. The other values listed are relatively stable and less urgent in this moment; they don’t carry the same immediate risk of complication during insulin-driven correction of DKA.

Potassium balance is the critical issue when treating diabetic ketoacidosis with insulin. In DKA, total body potassium is depleted from urinary losses, even if the blood potassium appears normal or high at presentation because of acidosis and insulin deficiency. When insulin infusion is started, potassium shifts into cells, which can cause a rapid and dangerous drop in serum potassium—hypokalemia. A potassium level of 3.1 mEq/L is clearly below the safe range and needs immediate attention. This value guides urgent management: hold or adjust insulin and begin potassium repletion to raise the serum level above about 3.3–3.5 mEq/L before continuing aggressive insulin therapy, to prevent life-threatening arrhythmias and muscle weakness. The other values listed are relatively stable and less urgent in this moment; they don’t carry the same immediate risk of complication during insulin-driven correction of DKA.