When should you switch to dextrose-containing fluids during DKA treatment?

When should you switch to dextrose-containing fluids during DKA treatment?

• A. When glucose falls below approximately 200 mg/dL
• B. After 24 hours
• C. When potassium normalizes
• D. At the start of infusion

Answer: (A)

The key idea is that continuing insulin to reverse the ketoacidosis is essential, but you need to prevent hypoglycemia as glucose falls. Once the patient’s blood glucose drops to about 200 mg/dL, you switch to dextrose-containing fluids. This lets you keep giving insulin to finish correcting ketosis and acidosis while providing a safe glucose level for the patient. Why this timing works: Insulin remains necessary to stop ketone production and to close the anion gap, but if you kept giving only saline, the risk of hypoglycemia would rise as glucose falls. By adding dextrose, you maintain serum glucose in a safe range (roughly 150–200 mg/dL) so insulin can continue to work without causing low blood sugar. You’d continue the insulin drip and fluids, often with a dextrose-containing solution, and monitor other factors like potassium, which can shift during treatment and may require supplementation. Not at the start, not after a fixed time like 24 hours, and not based on potassium status alone—these do not reliably indicate when to switch. The switch is driven by glucose level, specifically when it approaches 200 mg/dL.

The key idea is that continuing insulin to reverse the ketoacidosis is essential, but you need to prevent hypoglycemia as glucose falls. Once the patient’s blood glucose drops to about 200 mg/dL, you switch to dextrose-containing fluids. This lets you keep giving insulin to finish correcting ketosis and acidosis while providing a safe glucose level for the patient.

Why this timing works: Insulin remains necessary to stop ketone production and to close the anion gap, but if you kept giving only saline, the risk of hypoglycemia would rise as glucose falls. By adding dextrose, you maintain serum glucose in a safe range (roughly 150–200 mg/dL) so insulin can continue to work without causing low blood sugar. You’d continue the insulin drip and fluids, often with a dextrose-containing solution, and monitor other factors like potassium, which can shift during treatment and may require supplementation.

Not at the start, not after a fixed time like 24 hours, and not based on potassium status alone—these do not reliably indicate when to switch. The switch is driven by glucose level, specifically when it approaches 200 mg/dL.