Ischemic Cerebral Edema

Definition

Commonly occurring in large MCA infarctions, it is the development of profuse quantities of fluid collecting in brain tissue due to cellular swelling, breakdown of the blood-brain barrier, cerebrospinal fluid exuding from ependymal lining, or materials of blood clots or tissue injury creating an osmotic environment allowing the movement of water into interstitial spaces.

Signs/Symptoms

Neurological worsening, gradual loss of consciousness, headache, dizziness

Diagnostic Test

CT scan

Treatment Options

Nonpharmacologic

Hyperventilation, head elevation, maintenance of venous outflow, drainage of cerebrospinal fluid, hemicraniectomy

Pharmacologic

Mannitol

  • Use:
    Reduce increased intracranial pressure due to cerebral edema
  • MOA:
    Causes water to be drawn from cells to extracellular fluid and from erythrocytes to plasma
  • Dose:
    0.25 – 2g/kg IV over 30-60 minutes every 4-8 hours until serum osmolality between 300-310 mOsm/L is achieved. (Pressure may be reduced within 15 minutes after start of infusion.)
  • Monitoring:
    renal function, urine output, fluid balance, sodium and potassium concentration, central venous pressure
  • Adverse reactions:
    headache, nausea, vomiting, polyuria, dehydration
  • Dosage forms:
    15, 20, or 25% solutions
  • Investigative pharmacological options:
    glycerol, hypertonic saline, urea, barbiturates