What is the management approach for diabetic ketoacidosis (DKA) in pediatric patients?

Management of Diabetic Ketoacidosis in Pediatric Patients

Pediatric DKA requires immediate fluid resuscitation with isotonic saline followed by continuous IV insulin at 0.1 units/kg/hour WITHOUT an initial insulin bolus, with careful monitoring to prevent cerebral edema. 1

Diagnostic Criteria

DKA is defined by the following parameters 2, 1:

• Blood glucose >250 mg/dL
• Venous pH <7.3
• Serum bicarbonate <15 mEq/L
• Moderate ketonuria or ketonemia

Severity classification 1, 3:

• Mild: pH 7.25-7.30, bicarbonate 15-18 mEq/L, alert mental status
• Moderate: pH 7.00-7.24, bicarbonate 10-15 mEq/L, drowsy mental status
• Severe: pH <7.00, bicarbonate <10 mEq/L, stupor/coma

Initial Assessment and Laboratory Evaluation

Obtain STAT labs including 1:

• Arterial or venous blood gases
• Complete blood count with differential
• Plasma glucose, BUN, electrolytes, creatinine
• Urinalysis
• Direct measurement of β-hydroxybutyrate (preferred over nitroprusside method) 1, 3

Calculate corrected sodium by adding 1.6 mEq to the measured sodium for each 100 mg/dL glucose above 100 mg/dL 1, 3.

Fluid Management Protocol

Initial Resuscitation

Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour to restore circulatory volume 1, 4. This initial bolus should precede insulin administration by 1-2 hours 4, 5.

Subsequent Fluid Therapy

After initial resuscitation 2, 1:

• Use 0.45% saline for deficit replacement
• Calculate total fluid requirements at 1.5 times the 24-hour maintenance (approximately 5 mL/kg/hour)
• Do not exceed 2 times maintenance requirements
• Rehydrate evenly over 48 hours to minimize risk of cerebral edema 6, 4

The potassium in solution should be 1/3 KPO₄ and 2/3 KCl or K-acetate 2.

Insulin Therapy

Critical: Do NOT administer an initial insulin bolus in pediatric patients 1, 5. This represents a key difference from older protocols and reduces cerebral edema risk.

Insulin Infusion Protocol

• Start continuous IV regular insulin at 0.1 units/kg/hour after fluid resuscitation has begun 2, 1, 4
• Delay insulin by 1-2 hours after starting fluids 1, 4
• Continue insulin infusion at or above 0.1 units/kg/hour until ketoacidosis resolves 6

Glucose Management During Treatment

When blood glucose falls to 200-250 mg/dL 3:

• Add dextrose to IV fluids
• Continue insulin infusion to clear ketones (do not reduce insulin rate)

Potassium Replacement

Despite total-body potassium depletion, patients often present with hyperkalemia 2.

Begin potassium replacement when serum potassium falls below 5.5 mEq/L and adequate urine output is confirmed 2, 1, 3.

Standard replacement 2, 1:

• Add 20-30 mEq potassium per liter of infusion fluid
• Use 2/3 KCl and 1/3 KPO₄
• Target serum potassium 4-5 mEq/L

Critical exception: If patient presents with significant hypokalemia, begin potassium replacement with fluid therapy and delay insulin until potassium ≥3.3 mEq/L to avoid arrhythmias, cardiac arrest, or respiratory muscle weakness 2.

Bicarbonate Therapy

Bicarbonate use is NOT recommended in pediatric DKA 2, 3, 4.

The evidence shows 2:

• At pH ≥7.0, reestablishing insulin activity blocks lipolysis and resolves acidosis
• No randomized studies exist in pediatric patients with pH <6.9
• Bicarbonate administration increases risk of cerebral edema 6

If pH remains below 6.9 after initial treatment in adults, bicarbonate may be considered, but this is contraindicated in children 4.

Monitoring Protocol

Frequent Monitoring Requirements

• Blood glucose every 1-2 hours until stable 1
• Serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH every 2-4 hours 1, 3
• Neurological checks hourly to detect early signs of cerebral edema 1

After initial diagnosis, venous pH and anion gap adequately monitor acidosis resolution (venous pH typically 0.03 units lower than arterial) 3.

Resolution Criteria

DKA is considered resolved when 2, 1, 3:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Note: Ketonemia typically takes longer to clear than hyperglycemia 3.

Transition to Subcutaneous Insulin

Start subcutaneous insulin 2-4 hours BEFORE discontinuing IV insulin to prevent rebound hyperglycemia and recurrence of ketoacidosis 1, 3.

Continue IV insulin for 1-2 hours after administering subcutaneous insulin 1.

For newly diagnosed patients, initiate 0.5-1.0 units/kg/day as a multidose regimen of short- and intermediate-/long-acting insulin 2.

Cerebral Edema Prevention

Cerebral edema is the most common cause of death during pediatric DKA 6, 4.

Risk factors for cerebral edema 6:

• Severity of acidosis at presentation
• Greater hypocapnia (after adjusting for degree of acidosis)
• Higher blood urea nitrogen concentration
• Treatment with bicarbonate

Prevention strategies 2, 1:

• Gradual correction of glucose and osmolality
• Judicious use of isotonic or hypotonic saline based on serum sodium and hemodynamic status
• Avoid excessive fluid administration (do not exceed 2 times maintenance)
• Rehydrate over 48 hours, not faster
• NO initial insulin bolus
• NO bicarbonate therapy

If cerebral edema is suspected, intervene rapidly with mannitol or hypertonic saline infusion 4.

Common Pitfalls to Avoid

• Do not rely on urine ketones for diagnosis or monitoring, as nitroprusside method doesn't measure β-hydroxybutyrate 1, 3
• Do not give an initial insulin bolus in pediatric patients 1, 5
• Do not start insulin before fluid resuscitation 4
• Do not discontinue insulin prematurely before ketoacidosis fully resolves 3
• Do not use bicarbonate except possibly in extreme acidosis (pH <6.9) in adults, but contraindicated in children 4
• Do not rehydrate too rapidly (increases cerebral edema risk) 6, 4

Prevention of Recurrent DKA

Recurrent DKA is almost always due to insulin omission 1, 4. Prevention requires 1:

• Education about signs and symptoms of DKA
• 24-hour telephone availability for families
• Ketone monitoring during illness
• Comprehensive psychological support for patients with recurrent DKA