In diabetic ketoacidosis management, when should you switch from normal saline to dextrose-containing fluids?

• A. When blood glucose approaches 200 mg/dL
• B. When potassium drops below 3.3
• C. After 6 hours regardless of glucose
• D. Immediately after starting fluids

Answer: (A)

In DKA, the goal is to restore volume, suppress ketogenesis, and correct acidosis with insulin, while keeping blood glucose from dropping too quickly. You start with normal saline to rehydrate and improve perfusion, then you continue the insulin drip to shut down ketone production and resolve the acidosis. You switch to dextrose-containing fluids once the blood glucose gets to about 200 mg/dL to prevent hypoglycemia as insulin continues to work. This allows you to keep giving insulin to finish correcting the metabolic abnormalities while glucose stays at a safe level. Potassium and other factors are managed separately, so the switch isn’t driven by a potassium value or by a fixed time.