Cerebral edema in DKA

Background

• 1% of patients with DKA
• Almost all affected patients are <20yr
• Associated with initial bicarb level; not rate of glucose drop
  • Children presenting with higher blood urea nitrogen levels and more severe acidosis are at higher risk

Pathophysiology

• Thought to be due to cerebral hypoperfusion and less likely osmotic shifts with rapid infusion of IVF's

Risk Factors

• Age <5yo
• Severe hyperosmolality
• Failure of sodium to rise with therapy
• Severe acidosis
• Previous episodes of DKA
• Late presentation for medical evaluation
• Overaggressive fluid resuscitation is NOT a risk factor

Clinical Features

• Begins 6-12hr after onset of therapy or may begin before initiation of treatment or up to 48h afterward
  • Many appear to be improving from their DKA before deteriorating from cerebral edema
• Premonitory symptoms:
  • Headache
  • Incontinence
  • Seizure
  • Acute mental status changes
  • Signs of herniation

Differential Diagnosis

Hyperglycemia

• Physiologic stress response (rarely causes glucose >200 mg/dL)
• Diabetes mellitus (main)
  • Nonketotic hyperglycemia
  • Hyperosmolar hyperglycemic state (HHS/HONC)
  • Diabetic ketoacidosis (adult)
  • Diabetic ketoacidosis (peds)
    • Cerebral edema in DKA
  • Diabetic foot infection
  • Diabetic peripheral neuropathy
• Hemochromatosis
• Iron toxicity
• Sepsis

Evaluation

• Stat head CT (non-contrast)
• Capillary glucose measurement to rule out hypoglycemia as the cause of altered mental status

Management

• Head of bed at 30 degrees
• Mannitol 0.5-1gm/kg IV bolus over 20 minutes
  • Give a repeat does if there is an inadequate response
  • If 2 doses of mannitol are ineffective, consider 3% saline 10mL/kg over 30min
• Fluid restriction - decrease the IVF infusion rate by 30%
  • Treat noncardiogenic pulmonary edema, if present
• Consult neurosurgery (and PICU/ICU as appropriate)

Disposition

• Admit PICU/ICU

See Also

• Diabetes mellitus (main)
• DKA
• DKA (Peds)