Raised Intracranial Pressure, raised ICP

This is an abnormality that can occur due to multiple potential causes. It is treated based on the underlying cause and severity.

Diagnosis:

Intracranial pressure monitoring:

  • Ventriculostomy (external ventricular drain EVD)
  • Implantable ICP monitor
  • Lumbar drain

Raised opening pressure on Lumbar puncture (e.g. in cases of pseudotumor cerebri or meningitis). This should not be performed if mass effect is suspected.
May be suspected on clinical grounds based on examination and cross-sectional imaging.
MRI (indirect signs):

  • Optic nerve sheath to optic nerve diameter =or>2.5mm at it’s widest, suggests papilledema and raised intracranial pressure.
  • Used to assess the underlying cause or the consequences.

 

Investigations to consider:

CT head
MRI, MRV
ABG
Complete metabolic panel, Calculate osmolality, Measure osmolality, calculate osmolar gap (gives you a measure of Mannitol)
X-ray skull
Catheter angiography: central venous sinus thrombosis (CVST), aneurysms,
Lumbar puncture: only after CT negative for mass lesion
Isotope cisternography
Intracranial pressure monitor device
Ventriculostomy (external ventricular drain)

Treatment:

Treat the cause
Keep head slightly elevated

Interventions to consider:

Steroids: for neoplastic lesions (tumors) only. Contraindicated in traumatic brain injury (TBI) and not beneficial in stroke
Hyperosmolar therapy:

  • Mannitol:
    • Mannitol initial bolus 1-2g/kg, then 0.25-1g/kg q4-6hr PRN,
    • Keep osmolality 290 to 320mmol/L, Keep it near upper limit, keep Na <155. Calculate Osmolal gap: measured osmolality – calculated osmolality. Keep it <55 to avoid acute renal failure with mannitol.
    • Mannitol onset of action is ~90 min.
  • Hypertonic saline:
  • Hypertonic saline 23.4% NaCl, 30 – 60 mL IV bolus over 3 – 5 minute
  • Hypertonic saline 3% NaCl infusion via central line, titrate 30-50ml/hr, up to 30ml/hr can be done via peripheral IV
  • Hypertonic saline 3% NaCl bolus: 250 mL IV bolus over 20 – 30 minutes q4 – 6h
  • Titrate to Na+ 150-160mmol/l

Hyperventilation (works faster than mannitol):

  • Maintain blood gases within the following ranges:
    • PCO2 4-4.5 Kpa, 30-40 mmHg (or short period of 28-32 if severe)
    • PO2 >70 mmHg

Anelgesia and sedation:

  • Mild to Moderate to deep analgesia and sedation

More advanced interventions:

  • Induced Hypothermia
  • Pharmacological paralysis with NMJ blockers:
    • Atracurium: Loading dose = 0.5 mg/kg IV, Maintenance dose 4 – 25 mcg/kg/min continuous IV infusion
    • Vecuronium: Loading dose = 0.1 mg/kg IV, Maintenance dose 0.8 – 2 mcg/kg/min continuous IV infusion
  • Deep barbiturate coma; pentobarbitone, thiopentone

Surgical interventions:

  • Ventriculostomy (External ventricular drain EVD)
  • Hemicraniectomy, suboccipital craniotomy, wide bilateral craniotomies

Historical:

  • Glycerol 10% solution, 1g/kg NG q6h

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