What is the stepwise approach to managing diabetic ketoacidosis (DKA)?

Stepwise Approach to Managing Diabetic Ketoacidosis (DKA)

The management of diabetic ketoacidosis requires immediate fluid resuscitation with isotonic saline at 15-20 ml/kg/h, followed by insulin therapy, electrolyte replacement, and continuous monitoring until resolution criteria are met. 1

Diagnosis and Initial Assessment

• Definition: DKA is characterized by blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and moderate ketonemia or ketonuria 1
• Severity classification:
  • Mild: pH 7.25-7.30, bicarbonate 15-18 mEq/L, alert mental status
  • Moderate: pH 7.00-7.24, bicarbonate 10-14 mEq/L, alert/drowsy mental status
  • Severe: pH <7.00, bicarbonate <10 mEq/L, stupor/coma 1

Step 1: Fluid Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/h to expand intravascular volume and restore renal perfusion 1
• Aim to correct estimated fluid deficits (typically ~6 liters) within 24 hours 1
• Once hemodynamically stable, adjust fluid rate based on hydration status, electrolyte levels, and urine output

Step 2: Insulin Therapy

1. Initial insulin administration:

   • Exclude hypokalemia (K+ <3.3 mEq/L) before starting insulin
   • Administer IV bolus of regular insulin at 0.15 U/kg body weight
   • Follow with continuous infusion at 0.1 U/kg/h (approximately 5-7 U/h in adults) 1

2. Glucose management:

   • Target glucose between 150-200 mg/dL for mild and moderate/severe DKA 1
   • When glucose falls below 200-250 mg/dL, add dextrose to IV fluids while continuing insulin infusion 1

Step 3: Electrolyte Replacement

• 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) 1

• Bicarbonate therapy:

  • Only recommended when arterial pH is below 6.9
  • Not indicated when pH is 7.0 or higher 1

Step 4: Monitoring

• Hourly monitoring:

  • Vital signs
  • Neurological status
  • Blood glucose
  • Fluid input/output 1

• Every 2-4 hours monitoring:

  • Electrolytes
  • BUN
  • Creatinine
  • Venous pH 1

Step 5: Transition to Subcutaneous Insulin

• Once DKA resolves, initiate subcutaneous multi-dose insulin plan
• Continue IV insulin infusion for 1-2 hours after first subcutaneous dose to prevent rebound hyperglycemia 1
• Dosing recommendations:
  • For patients with established diabetes requiring >0.6 U/kg/day: Use basal-bolus regimen, reducing total daily dose by 20% 1
  • For insulin-naive patients: Start basal insulin at 0.2-0.3 U/kg/day 1

Resolution Criteria

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) 1

Special Considerations

Pediatric Patients (≤20 years)

• Use 1.5 times the 24-hour maintenance requirement (~5 ml/kg/hr) for fluid administration
• Higher risk of cerebral edema requires more cautious fluid administration 1

Pregnant Patients

• May present with euglycemic diabetic ketoacidosis
• Require immediate attention due to risk of feto-maternal harm 1

Patients with Cardiovascular Disease

• Require cardiac monitoring during treatment 1

Discharge Planning and Prevention

• Provide education on:
  • Diabetes self-management
  • Glucose monitoring
  • When to seek medical attention
  • Sick-day management
  • Proper medication administration 1
• Schedule outpatient follow-up within 1 month of discharge (or within 1-2 weeks if glycemic management medications were changed) 1

Common Pitfalls to Avoid

• Administering bicarbonate when pH >7.0 (not recommended)
• Discontinuing insulin infusion too early after glucose normalization (continue until ketoacidosis resolves)
• Failing to add dextrose to IV fluids when glucose falls below 200-250 mg/dL
• Inadequate potassium replacement leading to hypokalemia
• Overlooking precipitating factors (infection, medication non-adherence, new-onset diabetes)
• Too rapid correction of hyperosmolality in mixed DKA/HHS presentations, which increases risk of cerebral edema 1, 2