What is the preferred dextrose-containing fluid for the management of diabetic ketoacidosis (DKA)?

Preferred Dextrose-Containing Fluid for DKA

Switch to 5% dextrose in 0.45% saline (D5 half-normal saline) with 20-30 mEq/L potassium when serum glucose reaches 250 mg/dL, and continue insulin infusion until ketoacidosis fully resolves. 1, 2

Timing of Dextrose Addition

• Add dextrose-containing fluids when plasma glucose falls to 250 mg/dL in DKA (or 300 mg/dL in hyperosmolar hyperglycemic state). 1
• Never stop insulin infusion when adding dextrose—continue insulin at 0.1 unit/kg/hour until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L). 2, 3
• The goal is to maintain glucose between 150-200 mg/dL while insulin continues to clear ketones, which takes longer than correcting hyperglycemia. 2

Specific Fluid Composition for Adults

• Use 5% dextrose in 0.45% saline (D5 half-normal saline) as the standard dextrose-containing fluid. 1, 2
• Alternative formulation: 5% dextrose in 0.45-0.75% NaCl, with the saline concentration adjusted based on corrected serum sodium levels. 1, 2
• Always add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO4) to dextrose-containing fluids once renal function is confirmed. 2, 3

Pediatric Considerations

• For children under 20 years, use 5% dextrose with 0.45-0.75% NaCl, adjusting saline concentration based on serum sodium. 2
• Never use D50W in pediatric patients—it is too hypertonic and irritating to veins; maximum concentration should be D10W or D25W. 2
• In pediatric adrenal insufficiency with DKA, D10NS at 20 mL/kg may be used during the first hour. 2

Critical Electrolyte Management

• Potassium must be added to all dextrose-containing fluids at 20-40 mEq/L (2/3 KCl or potassium-acetate and 1/3 KPO4). 1, 2
• Do not add potassium if serum K+ is <3.3 mEq/L until it is corrected, as insulin therapy will further lower potassium and risk fatal arrhythmias. 2, 3
• Target serum potassium 4-5 mEq/L throughout treatment. 3

Special Clinical Scenarios

Euglycemic DKA

• Start dextrose-containing fluids immediately alongside insulin to prevent hypoglycemia while correcting ketoacidosis. 2
• This occurs especially with SGLT-2 inhibitor use, pregnancy, or prolonged fasting. 2

Two-Bag Method (Alternative Approach)

• Some centers use a "two-bag" or "three-bag" system with identical fluids except one contains 10% dextrose, allowing rapid adjustment of glucose infusion rate without changing total fluid or insulin rates. 4, 5
• This method is associated with earlier correction of acidosis, shorter insulin infusion duration, and fewer fluid bag changes. 5
• The Dallas protocol using this approach showed extremely low rates of cerebral edema (0.5%) and death (0.08%). 4

Common Pitfalls to Avoid

• Never decrease or stop insulin infusion when adding dextrose—ketoacidosis resolution requires continued insulin even after glucose normalizes. 2, 3
• Never use dextrose-containing fluids before glucose reaches 250 mg/dL unless treating euglycemic DKA. 1
• Never omit potassium from dextrose-containing fluids—insulin drives potassium intracellularly, and hypokalemia can cause fatal arrhythmias. 2, 3
• Never allow osmolality to decrease faster than 3 mOsm/kg/hour—this causes cerebral edema, especially in children. 2

Monitoring During Dextrose Phase

• Check blood glucose every 1-2 hours and adjust dextrose concentration or insulin rate to maintain glucose 150-200 mg/dL. 2, 3
• Monitor serum electrolytes, glucose, BUN, creatinine, and venous pH every 2-4 hours. 2, 3
• Continue monitoring β-hydroxybutyrate (preferred) rather than nitroprusside method, as the latter only measures acetoacetic acid and acetone, not the predominant ketone. 2, 3