In DKA fluid therapy, when is it appropriate to switch from 0.9% NaCl to 0.45% NaCl?

In DKA fluid therapy, when is it appropriate to switch from 0.9% NaCl to 0.45% NaCl?

• A. When the patient is hemodynamically stable and the glucose is approximately 200 mg/dL.
• B. Immediately after starting fluids.
• C. When glucose falls below 100 mg/dL.
• D. Only after 48 hours.

Answer: (A)

In DKA, you begin with isotonic saline to restore intravascular volume and kidney perfusion. Once the patient is hemodynamically stable and blood glucose has fallen to about 200 mg/dL, switching to a hypotonic fluid like 0.45% NaCl helps provide free water for ongoing hydration as insulin continues to lower glucose. This avoids giving too much sodium while still supporting fluid replacement, and it aligns with continuing insulin therapy and typically adding dextrose once glucose nears 200 mg/dL to prevent hypoglycemia. Switching earlier would shortchange initial volume resuscitation; waiting until glucose is under 100 mg/dL or delaying for days would hinder correction of osmotic diuresis and dehydration.

In DKA, you begin with isotonic saline to restore intravascular volume and kidney perfusion. Once the patient is hemodynamically stable and blood glucose has fallen to about 200 mg/dL, switching to a hypotonic fluid like 0.45% NaCl helps provide free water for ongoing hydration as insulin continues to lower glucose. This avoids giving too much sodium while still supporting fluid replacement, and it aligns with continuing insulin therapy and typically adding dextrose once glucose nears 200 mg/dL to prevent hypoglycemia. Switching earlier would shortchange initial volume resuscitation; waiting until glucose is under 100 mg/dL or delaying for days would hinder correction of osmotic diuresis and dehydration.