What is the inpatient management protocol for diabetic ketoacidosis (DKA)?

Inpatient Management Protocol for Diabetic Ketoacidosis (DKA)

The standard inpatient DKA protocol consists of aggressive fluid resuscitation with isotonic saline at 15-20 ml/kg/hour for the first hour, followed by 0.45% saline at 4-14 ml/kg/hour based on corrected sodium levels, continuous intravenous regular insulin at 0.1 units/kg/hour without bolus, and careful electrolyte replacement with monitoring every 2-4 hours until resolution. 1

Diagnosis and Initial Assessment

• DKA diagnostic criteria:

  • Blood glucose >250 mg/dL
  • Arterial pH <7.3
  • Bicarbonate <15 mEq/L
  • Moderate ketonemia or ketonuria 2

• Severity classification:

  Parameter	Mild	Moderate	Severe
  Arterial pH	7.25-7.30	7.00-7.24	<7.00
  Bicarbonate (mEq/L)	15-18	10-14	<10
  Mental Status	Alert	Alert/drowsy	Stupor/coma

• Initial laboratory evaluation:

  • Arterial blood gases
  • Complete blood count with differential
  • Blood glucose, BUN, creatinine
  • Electrolytes and chemistry profile
  • Urinalysis
  • ECG 2, 1

Fluid Therapy

1. First hour: Isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour to expand intravascular volume and restore renal perfusion 1

2. Subsequent fluid therapy:

   • If corrected sodium is normal or elevated: 0.45% NaCl at 4-14 ml/kg/hour
   • If corrected sodium is low: Continue 0.9% NaCl at similar rate
   • Formula for corrected sodium: Measured sodium + 1.6 × [(glucose mg/dl - 100)/100] 2, 1

3. Add dextrose when blood glucose reaches 250-300 mg/dL (use 5% dextrose with 0.45% NaCl) to prevent hypoglycemia and cerebral edema 1

4. Target: Correct estimated fluid deficits within 24 hours, not exceeding osmolality change of 3 mOsm/kg/hour 2

Insulin Therapy

1. Start insulin after initial fluid resuscitation (1-2 hours after fluids begin)

   • Regular insulin by continuous IV infusion at 0.1 units/kg/hour
   • No initial bolus needed 1

2. Adjust insulin rate:

   • Target glucose decrease of 50-75 mg/dL/hour
   • Consider reducing insulin to 0.05 units/kg/hour when glucose falls below 250 mg/dL to prevent hypoglycemia 1, 3

3. Transition to subcutaneous insulin:

   • Start basal insulin 2-4 hours before discontinuing IV insulin to prevent hyperglycemic rebound
   • DKA resolution criteria: glucose <200 mg/dL, bicarbonate ≥18 mEq/L, venous pH >7.3 1

Electrolyte Management

1. Potassium replacement:

   • Begin when serum K+ <5.5 mEq/L and adequate urine output is confirmed
   • Add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO4) to IV fluids 2, 1
   • If K+ <3.3 mEq/L, hold insulin and give potassium replacement first

2. Phosphate: Generally included in replacement as KPO4, especially with severe hypophosphatemia 2

3. Bicarbonate: Not recommended for most patients with pH >6.9 4

Monitoring Protocol

1. Hourly monitoring:

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

2. Every 2-4 hours:

   • Electrolytes
   • BUN, creatinine
   • Venous pH 1

3. Watch for complications:

   • Cerebral edema (headache, altered mental status, seizures)
   • Hypoglycemia
   • Hypokalemia
   • Fluid overload (increased JVP, pulmonary crackles, peripheral edema) 1

Special Considerations

1. Cerebral edema prevention (especially important in pediatric patients):

   • Avoid too rapid correction of serum osmolality
   • Monitor neurological status closely
   • Limit initial fluid expansion in children 1, 5

2. Euglycemic DKA:

   • Consider in patients on SGLT2 inhibitors
   • DKA can occur with normal or only slightly elevated glucose levels 6

3. Precipitating factors:

   • Identify and treat underlying causes (infection, missed insulin, new diagnosis)
   • Obtain appropriate cultures if infection suspected 2, 1

Discharge Planning

1. Education on diabetes self-management, glucose monitoring, and when to seek medical attention

2. Medication review, especially insulin administration technique

3. Schedule follow-up appointment prior to discharge 1

Common Pitfalls to Avoid

• Delaying insulin therapy (should start within 1-2 hours of fluid initiation)
• Failing to monitor potassium (hypokalaemia occurs in ~50% of cases during treatment)
• Abrupt discontinuation of IV insulin without overlap with subcutaneous insulin
• Inadequate fluid resuscitation or too rapid correction of osmolality
• Missing euglycemic DKA, especially in patients on SGLT2 inhibitors 1, 6, 3