Raised Intracranial Pressure (2*) Flashcards
What is the normal range?
What are causes of raised ICP?
➊ < 15mm/Hg
➋ • Brain tumours – Primary or Metastatic
‣ Most common ca. to metastasise to brain – Lung, Breast, RCC, Melanoma
• Intracranial HTN
• Haemorrhage
• Infection – Meningitis, Encephalitis, Brain abscess
• Hydrocephalus
• Cerebral oedema
• Fluid outflow obstruction – Rare causes include Chiari malformation, Vasculitis, Craniosynostosis (abnormal skull growth)
How does it present?
What’s one of the very late signs?
➊ • Headache – Persistent, Worse in morning/on coughing/leaning forward/straining
• Papilloedema
• Vomiting
• Pupil changes – first constriction, dilation later
• Altered GCS - drowsiness, listlessness, irritability
• Peripheral visual field loss
➋ Cushing’s response – fall in HR, rise in BP (late, and very worrying sign)
How should it be investigated?
What’s the worry with doing an LP?
➊ • F&E, FBC, LFT, Glu, Serum osmolality, Clotting, Blood culture
• Consider toxicology screen
• CXR – Any source of infection indicating abscess
• CT Head - New onset headache and focal neurological symptoms indicates this should be done urgently
• Consider LP if safe
➋ Could disrupt the ICP, therefore dramatically increasing the risk of herniation/coning
Management:
What are the aims?
What should be given to these pts?
→ What drug is this better than? Why?
What else could be done?
➊ • Maintain cerebral perfusion by raising MAP
• Lower ICP
• Treat underlying cause
➋ Hypertonic Saline – Draws fluid back into vessels
→ Mannitol in short-term ICP redution as mannitol carries additional risks e.g. anaphylaxis
➌ • If intubated, Hyperventilate the pt – This will decrease pCO2, therefore causing cerebral vasoconstriction and reducing ICP very quickly
• Barbiturate coma – Used only in refractory cases
