What are the guidelines for maintenance fluids in diabetic ketoacidosis (DKA)?

Guidelines for Maintenance Fluids in Diabetic Ketoacidosis (DKA)

For maintenance fluids in diabetic ketoacidosis (DKA), isotonic saline (0.9% NaCl) should be infused at 15-20 ml/kg/hr initially, with the goal of correcting estimated fluid deficits within 24 hours. 1

Initial Fluid Resuscitation

• Begin with 0.9% NaCl at 15-20 ml/kg/hr to expand intravascular volume and restore renal perfusion
• Typical total body water deficit in DKA is approximately 6 liters
• After initial resuscitation, adjust fluid rate based on:
  • Hemodynamic status
  • Hydration status
  • Urine output
  • Electrolyte levels

Recent Evidence on Fluid Type

Recent evidence suggests that Balanced Electrolyte Solutions (BES) may be superior to 0.9% saline for DKA management. A 2024 meta-analysis found that BES resolves DKA faster than 0.9% saline by approximately 5.36 hours and results in better electrolyte profiles 2. This represents an emerging shift in practice that clinicians should consider, although most current guidelines still recommend 0.9% saline as first-line.

Electrolyte Management

Potassium Replacement

• Add potassium to IV fluids once serum levels fall below 5.5 mEq/L and adequate urine output is confirmed
• Standard replacement: 20-30 mEq potassium per liter of IV fluid (2/3 KCl and 1/3 KPO₄)
• Target serum potassium concentration: 4-5 mEq/L
• If initial potassium is <3.3 mEq/L, begin potassium replacement before starting insulin to prevent arrhythmias and respiratory muscle weakness 3, 1

Bicarbonate Management

• For pH ≥7.0: No bicarbonate administration needed
• For pH 6.9-7.0: Consider 50 mmol sodium bicarbonate diluted in 200 ml sterile water, infused at 200 ml/hr
• For pH <6.9: Consider 100 mmol sodium bicarbonate added to 400 ml sterile water, given at 200 ml/hr 3

Pediatric Considerations

For pediatric patients (≤20 years):

• Typically use 1.5 times the 24-hour maintenance requirement (approximately 5 ml/kg/hr)
• Do not exceed twice the maintenance requirement
• Potassium in solution should be 1/3 KPO₄ and 2/3 KCl or K-acetate 3
• More cautious fluid administration is recommended due to higher risk of cerebral edema

Monitoring During Fluid Therapy

• Hourly monitoring:
  • Vital signs
  • Neurological status
  • Blood glucose
  • Fluid input/output
• Every 2-4 hours:
  • Serum electrolytes
  • BUN and creatinine
  • Venous pH 1

Special Populations

• Cardiac patients: More cautious fluid administration with cardiac monitoring
• Renal failure: Adjust fluid and electrolyte replacement based on renal function
• Elderly: May require slower fluid replacement to prevent volume overload
• Pregnant patients: Require careful monitoring as they may present with euglycemic DKA 1

Transition from IV to Subcutaneous Insulin

DKA is considered resolved when:

• Blood glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap normalized (<12 mEq/L) 3, 1

At this point, transition to subcutaneous insulin can be initiated when the patient is able to take oral fluids.

Common Pitfalls to Avoid

1. Administering bicarbonate when pH is ≥7.0 (not recommended)
2. Delaying potassium replacement in patients with normal or low potassium levels
3. Overly aggressive fluid resuscitation in pediatric patients, increasing risk of cerebral edema
4. Relying solely on nitroprusside method for ketone monitoring (does not measure β-hydroxybutyrate)
5. Failing to adjust fluid therapy for patients with cardiac or renal comorbidities