Raised intracranial pressure Flashcards
Pathophysiology
Normal ICP is 7-15 mmHg in adults in supine position
Cerebral perfusion pressure is net pressure gradient causing cerebral blood flow to brain
Causes
IIH
Traumatic head injuries
Infection (meningitis)
Tumours
Hydrocephalus
Features
Headache
Vomiting
Reduced level of consciousness
Cushing’s triad
Cushing’s triad
Widening pulse pressure
Bradycardia
Irregular breathing
Investigations
CT/MRI key to investigate underlying cause
Monitoring
Invasive ICP
Catheter placed into lateral ventricles of brain to monitor pressure
May also be used to collect CSF sample and drain small amounts of CSF to reduce pressure
Management
Investigate and treat underlying cause
Head elevation to 30’
IV mannitol
Controlled hyperventilation
Removal of CSF
Controlled hyperventilation
Aim to reduce pCO2 –> vasoconstruction of the cerebral arteries –> reduce ICP
Leads to rapid, temporary lowering if ICP
Caution needed as may reduce blood flow to already ischaemic parts of the brain
Techniques for removal of CSF
Drain from intraventricular monitor
Repeated LP
Ventriculoperitoneal shunt (for hydrocephalus)