What is the fluid of choice in diabetic ketoacidosis (DKA)?

Fluid of Choice in Diabetic Ketoacidosis

Initial Resuscitation: Start with Isotonic Saline

Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in the first hour) for all adult DKA patients without cardiac compromise. 1, 2, 3

This aggressive initial bolus is critical for:

• Expanding intravascular volume 1
• Restoring renal perfusion 1
• Stabilizing hemodynamics regardless of measured sodium levels 2

Subsequent Fluid Selection: Guided by Corrected Sodium

After the initial hour, fluid choice depends on the corrected serum sodium (not the measured value): 1

Calculate Corrected Sodium First

• Add 1.6 mEq/L to measured sodium for every 100 mg/dL glucose above 100 mg/dL 1, 2, 3
• Common pitfall: Never use measured sodium without correction—this leads to inappropriate fluid selection and can worsen outcomes 2

Fluid Selection Algorithm

• If corrected sodium is normal or elevated: Switch to 0.45% NaCl (half-normal saline) at 4-14 mL/kg/hour 1, 3
• If corrected sodium is low: Continue 0.9% NaCl at 4-14 mL/kg/hour 1, 3

Emerging Evidence: Balanced Electrolyte Solutions

While guidelines recommend normal saline, recent high-quality research demonstrates that balanced electrolyte solutions (BES) resolve DKA faster than 0.9% saline (mean difference of 5.36 hours faster). 4, 5

Advantages of Balanced Solutions

• Faster DKA resolution (13 vs 17 hours) 5
• Lower post-resuscitation chloride levels (4.26 mmoL/L lower) 4
• Higher bicarbonate levels (1.82 mmoL/L higher) 4
• Avoids hyperchloremic metabolic acidosis from large-volume normal saline 4, 5

Clinical Consideration

Despite guideline recommendations for normal saline, balanced crystalloid solutions may be considered as first-line therapy based on 2024-2025 evidence showing superior outcomes. 4, 5 However, normal saline remains the standard in most protocols. 1

Essential Electrolyte Supplementation

Once renal function is confirmed and urine output established: 1, 3

• Add 20-30 mEq/L potassium to IV fluids 1, 3
• Use 2/3 KCl and 1/3 KPO4 mixture 1, 3
• Critical pitfall: Never add potassium before confirming adequate renal function—this can cause life-threatening hyperkalemia 3

Safety Parameters: Prevent Cerebral Edema

The induced change in serum osmolality must not exceed 3 mOsm/kg/hour. 1, 2, 3

• Correct estimated fluid deficits evenly over 24 hours 1, 3
• Monitor blood pressure, urine output, and mental status continuously 1, 3
• Critical pitfall: Overly rapid correction causes osmotic demyelination syndrome and cerebral edema, especially in children 2, 3

Special Populations

Patients with Cardiac or Renal Compromise

• Reduce standard fluid rates by approximately 50% 3
• Monitor serum osmolality and perform frequent cardiac/renal assessments 1
• Critical pitfall: Excessive fluids precipitate pulmonary edema in these patients 3

Pediatric Patients (<20 years)

• Initial: 0.9% NaCl at 10-20 mL/kg/hour for first hour 1, 3
• Never exceed 50 mL/kg over first 4 hours 1, 3
• Subsequent: 0.45-0.9% NaCl at 1.5 times maintenance (5 mL/kg/hour) 1
• Higher cerebral edema risk requires more conservative approach 3

Monitoring Requirements

Check every 2-4 hours: 1, 3

• Serum electrolytes (including corrected sodium)
• Glucose
• BUN/creatinine
• Venous pH (arterial blood gases generally unnecessary) 1, 3
• Anion gap 3

Continue monitoring sodium throughout treatment—not just initially—to prevent overcorrection as DKA resolves. 2