subarachnoid haemorrhage W4 Flashcards
subarachnoid haemorrhage definition
haemorrhage into the subarachnoid space
typical cause of subarachnoid haemorrhage
rupture of aneurysm (most commonly around circle of Willis)
what is an aneurysm
abnormally dilated region of a blood vessel
mortality of subarachnoid haemorrhage
35%
risk factors of subarachnoid haemorrhage (SAH)
hypertension, smoking
family history of aneurysmal SAH
connective tissue disorders (Ehlers-Danlos)
clinical features of SAH?
‘thunderclap headache’
10/10 pain
sudden onset
reduced consciousness, seizures, focal neurological signs, meningism
sudden/rapid death can occur
may arise after exertion, most are spontaneous
diagnosis of SAH?
most are visible on CT brain (sensitivity declines after 12 hrs)
appropriate history and negative CT brain, LP performed
LP must be 12 hours after onset
why must an LP be done 12 hours after SAH onset
allows time for blood breakdown products
what is xanthochromia?
presence of bilirubin in CSF
what to do if xanthochromia detected in SAH?
angiography (CT, MRI or invasive) to look for culprit lesion
management of SAH?
supportive care
nimodipine
secure aneurysm
ongoing rehab and long term care
what does nimodipine do
prevents development of delayed cerebral ischaemia (which increases morality) by preventing arterial vasospasm
SAH management - securing aneurysm?
prevents rebleeding
typically coiling (via endovascular procedure) or clipping (neurosurgical)
what is bilirubin?
yellowish pigment made during breakdown of red blood cells
