Diabetic Ketoacidosis

Definition & Pathophysiology - Sugar Storm Genesis

• DKA Triad:
  • Hyperglycemia: BG > 200 mg/dL
  • Ketonemia (β-OHB ≥ 3) / Ketonuria (≥2+)
  • Acidosis: pH < 7.3 or $HCO_3^-$ < 15
• Pathogenesis:
  • Core: Insulin deficiency (absolute/relative).
  • ↑ Counter-regulatory hormones (glucagon, etc.) exacerbate.
  • Key Outcomes:
    • ↓ Glucose use, ↑ production → Hyperglycemia → Osmotic diuresis.
    • ↑ Lipolysis → ↑ FFAs → ↑ Ketogenesis → Ketonemia, acidosis.

⭐ DKA is precipitated by absolute or relative insulin deficiency leading to hyperglycemia, ketogenesis, and metabolic acidosis. Counter-regulatory hormones (glucagon, cortisol, catecholamines, growth hormone) exacerbate this state.

Clinical Features & Diagnosis - Red Alert Signs

• Classic Triad: Polyuria, polydipsia, polyphagia.
• GI Symptoms: Nausea, vomiting, abdominal pain.
• Dehydration: ↓ Skin turgor, dry mucous membranes, sunken eyes, tachycardia.
• Respiratory: Kussmaul breathing (deep, rapid), fruity breath (acetone).
• Neurological: Altered sensorium (lethargy to coma) - ⚠️ Cerebral edema risk!
• Diagnostic Criteria (Lab):
  • Hyperglycemia: Blood glucose > 200 mg/dL (> 11 mmol/L).
  • Metabolic Acidosis: Venous pH < 7.3 OR Serum bicarbonate < 15 mmol/L.
  • Ketosis: Ketonemia (β-hydroxybutyrate ≥ 3 mmol/L) OR significant ketonuria.
  • Elevated Anion Gap: $AG = Na^+ - (Cl^- + HCO_3^-)$ > 12.

⭐ Kussmaul breathing (deep, rapid respirations) is a clinical sign of severe metabolic acidosis as the body attempts to compensate by blowing off CO2.

Management Principles - Rescue Protocol

• 📌 F-I-P-M for DKA: Fluids, Insulin, Potassium, Monitoring.
• Fluids (IV):
  • Initial: NS (0.9% NaCl) 10-20 mL/kg bolus (1 hr). Repeat if shock.
  • Deficit + Maintenance: Correct total fluid deficit over 48 hrs + maintenance.
    • $Fluid\ Deficit\ (L) = % \text{ dehydration} \times \text{body weight (kg)}$
  • Add Dextrose fluids (e.g., D5NS, D5 0.45% Saline) when BG < 250-300 mg/dL.
• Insulin:

  ⭐ Insulin therapy should only be initiated after starting fluid resuscitation and ensuring serum potassium is ≥ 3.3 mEq/L to prevent life-threatening hypokalemia.

  • Start 1-2 hrs after initiating fluid therapy.
  • Continuous IV infusion: 0.05-0.1 U/kg/hr. (NO insulin bolus).
• Potassium (K+):
  • Anticipate ↓K+ with insulin.
  • If K+ < 3.3 mEq/L: Hold insulin, give K+ (20-40 mEq/L in IV fluid).
  • If K+ 3.3-5.5 mEq/L & urinating: Add K+ 20-40 mEq/L to IV fluids.
  • If K+ > 5.5 mEq/L: Defer K+ until urine output confirmed; recheck.
• Monitoring:
  • Hourly: BG, vitals, neurological status (for cerebral edema).
  • 2-4 hourly: Electrolytes (esp. K+), VBG (for pH, HCO3-), ketones.

Complications & Monitoring - Watchtower Duty

• Cerebral Edema: Most feared. Signs: headache, ↓HR, altered sensorium. Mannitol 0.5-1 g/kg IV.
• Hypokalemia: During insulin therapy. Monitor K+ closely.
• Hypoglycemia: Due to insulin. Monitor CBG hourly.
• Hyperchloremic acidosis (from NS).
• Others: Thrombosis, ARDS.
• Monitoring:
  • Hourly: Vitals, GCS, fluid I/O, CBG.
  • 2-4 hourly: Electrolytes (K+, Na+), VBG.
  • ECG & strict neuro watch.

⭐ Cerebral edema is the most dangerous complication of pediatric DKA, with early warning signs including headache, slowing heart rate, and altered mental status.

oka

High‑Yield Points - ⚡ Biggest Takeaways

• DKA triad: Hyperglycemia (>200 mg/dL), ketosis, & metabolic acidosis (pH <7.3, HCO3 <15).
• Fluids: Initial 0.9% NS (10-20 mL/kg); correct deficit over 48h to prevent cerebral edema.
• Insulin: 0.1 U/kg/hr IV after initial fluids; no IV bolus.
• Potassium: Add to IVF once K+ <5.5 mEq/L & urine output good; monitor.
• Cerebral edema: Most feared; treat with mannitol or 3% saline.
• Bicarbonate: Avoid unless pH <6.9 with severe cardiac dysfunction.