Diabetic Ketoacidosis (DKA) Management in a 25 kg Child with Severe Dehydration and Severe Metabolic Acidosis

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Step 1: Initial Assessment & Diagnosis

• Weight: 25 kg
• Severe dehydration (10%–12%) → Estimated fluid deficit: 2500–3000 mL
• Severe metabolic acidosis: Likely pH <7.0, HCO₃⁻ <10 mmol/L
• Glucose >200 mg/dL, Ketones positive, Anion gap metabolic acidosis
• Electrolyte imbalances: Often hypokalemia, hyponatremia, hyperglycemia

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Step 2: Fluid Resuscitation

Goal: Restore perfusion, correct dehydration, reduce glucose & ketones

1. Bolus Fluid (Normal Saline 0.9%)
   • 20 mL/kg over 1 hour
   • 25 kg × 20 mL/kg = 500 mL of NS over 1 hour
   • If still in shock, repeat 10-20 mL/kg bolus (up to 40-60 mL/kg)
2. Deficit Correction & Maintenance Fluids
   • Deficit: 2500–3000 mL (10–12% dehydration)
   • Maintenance: Using Holliday-Segar formula:
     • First 10 kg: 100 mL/kg = 1000 mL
     • Next 10 kg: 50 mL/kg = 500 mL
     • Remaining 5 kg: 20 mL/kg = 100 mL
     • Total Maintenance = 1600 mL/day (~67 mL/hr)
   • Deficit Replacement (2500 mL over 48 hrs) ≈ 50 mL/hr
   • Total Fluid Rate = 67 + 50 = 117 mL/hr

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Step 3: Insulin Therapy

• IV Regular Insulin at 0.05–0.1 U/kg/hr (after 1 hour of fluids)
• 0.1 U/kg/hr × 25 kg = 2.5 U/hr IV insulin
• DO NOT BOLUS INSULIN
• Continue insulin until pH >7.3, bicarbonate >15, and no ketonemia

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Step 4: Electrolyte Management

1. Potassium Replacement

• DKA patients are total body K+ depleted despite normal/high serum K+
• If K+ <3.3 mmol/L → Hold insulin, start K+ 40 mmol/L in IV fluids
• If K+ 3.3–5.5 mmol/L → Add K+ 30–40 mmol/L
• Formula for K+ requirement:
  • Deficit ≈ 4-6 mEq/kg
  • 25 kg × 5 mEq/kg = 125 mEq (to be given over 24-48 hrs)

2. Sodium Correction

• Corrected Na = Measured Na + [1.6 × (Glucose – 100) / 100]
• If hyponatremic (<130 mmol/L), correct slowly with 0.9% NaCl

3. Bicarbonate Therapy (Only in severe acidosis pH <6.9)

• NaHCO₃ dose = 0.3 × Weight × (Desired HCO₃ – Measured HCO₃)
• If pH <6.9, give 1-2 mEq/kg NaHCO₃ over 2 hours
• 25 kg × 0.3 × (10 – 5) = 37.5 mEq (over 2 hrs)

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Step 5: Transition to Subcutaneous Insulin

• When glucose <250 mg/dL, add 5–10% dextrose
• Overlap IV insulin with subcutaneous basal-bolus insulin for 1-2 hrs

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Summary of Calculations

✅ Fluids: 500 mL NS bolus, then 117 mL/hr maintenance
✅ Insulin: 2.5 U/hr IV
✅ Potassium: 125 mEq over 24-48 hrs
✅ Sodium Correction: Adjust for pseudohyponatremia
✅ Bicarbonate: Only if pH <6.9, ~37.5 mEq over 2 hours