Subarachnoid Haemorrhage Flashcards
SAH
Why do most SAH’s happen?
secondary to a Berry aneurysm
SAH
Typical presentation
- thunderclap headache
SAH
Describe the headache and associated symptoms
thunderclap
- nausea and vomiting
- photophobia
- visual disturbances
SAH
What is it usually triggered by?
exertion or sexual activity
SAH
What are some classical signs of someone who has had a SAH?
- reduced GCS
- meningism
- pyrexia
- signs of raised intracranial pressure (i.e. hypotension, bradycardia and papilloedema)
SAH
How is it diagnosed?
CT
SAH
CTs can miss a SAH. What other investigation can be done?
lumbar puncture
SAH
When does a CT scan become less reliable with picking up a SAH?
with time
(sensitivity of a CT scan is 95% at day 1, 74% at day 3, and 50% at day 7)
SAH
The diagnostic findings on an lumbar puncture are:
(2)
- blood in the CSF
- xanthochromia
SAH
What is xanthachromia and why does it occur?
the yellowing of CSF 12 hours after exposure to air, due to the breakdown of haemoglobin into bilirubin
SAH
Why might these investigations also be done?
- Routine blood tests (FBC, U&Es)
- Coagulation screen and group and save/crossmatch
- ECG
- Routine blood tests (FBC, U&Es) – to rule out another medical cause of the headache, and especially infective causes, as there is a significant overlap between the clinical features of SAH and meningitis
- Coagulation screen and group and save/crossmatch – these should be done in anticipation of future procedures and potential surgery.
- ECG – ST elevation is a sign of SAH, and SAH can cause dangerous arrhythmias.
SAH
In a severe presentation, how do we manage a pt?
A-E approach
SAH
In a severe presentation, how do we try and reduce cerebral ischaemia?
calcium channel blocker nimodipine is used to reduce vasospasm
SAH
In a severe presentation, what do we do if pt has a reduced GCS?
intubation
SAH
What drugs are used to reduce intracranial pressure?
Mannitol and inotropes
