What is the initial management for a patient presenting with diabetic ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis (DKA)

The initial management of diabetic ketoacidosis requires aggressive intravenous fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour during the first hour, followed by insulin therapy, electrolyte replacement, and identification of precipitating factors. 1

Diagnosis and Assessment

DKA is diagnosed based on the following criteria:

• Blood glucose >250 mg/dL
• Arterial pH <7.3 or serum bicarbonate <18 mEq/L
• Presence of ketones in urine or blood 1

Initial Laboratory Evaluation

• Plasma glucose
• Blood urea nitrogen/creatinine
• Serum ketones (preferably β-hydroxybutyrate)
• Electrolytes with calculated anion gap
• Serum osmolality
• Urinalysis and urine ketones
• Arterial blood gases
• Complete blood count with differential
• Electrocardiogram 1, 2

Additional Assessments

• Bacterial cultures (urine, blood, throat) if infection is suspected
• Chest X-ray if indicated
• HbA1c to determine if this is an acute episode in otherwise well-controlled diabetes 2

Treatment Algorithm

1. Fluid Therapy

• First hour: Isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour (approximately 1-1.5 liters in average adult) 2, 1
• Subsequent hours: Choice depends on hydration status, serum electrolytes, and urine output
  • If corrected serum sodium is normal or elevated: 0.45% NaCl at 4-14 ml/kg/hour
  • If corrected serum sodium is low: Continue 0.9% NaCl at similar rate 2
  • When glucose reaches 250 mg/dL: Add 5-10% dextrose to IV fluids 1

2. Insulin Therapy

• For moderate to severe DKA (pH <7.25): Continuous IV regular insulin at 0.1 units/kg/hour after fluid resuscitation has begun
• For mild DKA (pH 7.25-7.30): Can consider subcutaneous or intramuscular insulin every hour (initial dose 0.4-0.6 U/kg, followed by 0.1 U/kg/hour) 1
• Adjustment: When glucose reaches 250 mg/dL, decrease insulin infusion to 0.05-0.1 units/kg/hour and add dextrose to IV fluids 1

3. Electrolyte Replacement

• Potassium: Start replacement when serum potassium <5.2 mEq/L and patient is producing urine
  • Add 20-30 mEq potassium per liter of IV fluid (2/3 KCl and 1/3 KPO₄)
  • Monitor levels every 2-4 hours 1, 2
• Bicarbonate: Generally not recommended except in cases where arterial pH <6.9 in adults 1

4. Monitoring

• Blood glucose: Every 1-2 hours
• Electrolytes, BUN, creatinine: Every 2-4 hours
• Venous pH and anion gap: To follow resolution of acidosis 1

Resolution Criteria

DKA is considered resolved when:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH ≥7.3 1

Transition to Subcutaneous Insulin

Once DKA resolves:

1. Start a multiple-dose insulin regimen with short/rapid-acting and intermediate/long-acting insulin
2. Continue IV insulin infusion for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels
3. Avoid abrupt discontinuation of IV insulin 1

Common Pitfalls to Avoid

• Premature termination of IV insulin therapy
• Insufficient timing or dosing of subcutaneous insulin before discontinuing IV insulin 3
• Failing to replace potassium adequately
• Using bicarbonate unnecessarily
• Not identifying and treating the underlying precipitating cause
• Discontinuing IV insulin too early 1

Recent Developments

Recent evidence suggests that balanced fluids may be associated with faster DKA resolution compared to normal saline (13 hours vs 17 hours) 4. However, the most recent guidelines from the American Diabetes Association still recommend isotonic saline as the initial fluid of choice 1.

Special Considerations

• Patients with heart failure: More cautious fluid administration
• Pregnancy: Requires specialized management
• Renal disease: Adjust electrolyte replacement
• Elderly: May require more careful monitoring during fluid resuscitation 5