Subarachnoid Haemorrhage Flashcards
define subarachnoid haemorrhage?
Blood in subarachnoid.
usual cause?
trauma to head
RF for SAH?
o Age o HTN o Smoking o FHx o Polycystic kidney disease o Alcohol excess
causes of SAH are split into what two categories?
Traumatic and spontaneous
most common cause for spontaneous SAH?
Burst berry aneurysm
common location for a burst berry aneurysm?
o Junction between anterior communicating artery and
anterior cerebral artery
other causes of a spontaneous SAH?
-4
AV malformation
Mycotic aneurysm
Vertebra artery dissection
Tumour
Aneurysm at PcommA presses on what nerve?
CN 3
3rd nerve palsy from PCA aneurysm, how will eyes look?
down and out, ptosis, mydriasis
in which spaces will blood collect from a subarachnoid haemorrhage?
Basal cisterns and ventricles
blood collecting in ventricles will cause what complication?
Hydrocephalus
how many pts with SAH will get hydrocephalus?
-% wise
20-30%
drug given for hydrocephalus?
conclusive treatment for hydrocephalus?
mannitol
VP shunt
blood leaking in and around brain tissue will cause what?
explain pathophys behind the vasospasm in SAH?
vasospasm
explain pathophys behind the vasospasm in SAH?
blood breaks down > irritates nearby BVs > stops NO being made > vasospasm
initial prognosis for subarachnoid haemorrhage?
1/3 die
1/3 neuro deficit
1/3 completely fine
rebleed risk at 1 month?
-%
22%
difference between ischaemia and infarct?
ischaemia - less blood, reversible
infarct - cell death, irreversible
what electrolyte complication can happen from subarachnoid haemorrhage?
cerebellar salt wasting syndrome
in cerebellar salt wasting syndrome what electrolyte level changes and how does it change?
low Na+
cerebellar salt wasting syndrome effect on blood volume?
why
low blood volume
because low Na+
pathophysiology behind cerebellar salt wasting syndrome
SAH > peptides released > triggers Na+ excretion from kidneys, water naturally flows = hyponatraemic and hypovolaemic.
cerebellar salt wasting syndrome causes ↓Na+.
what complications can ↓Na+ cause/exacerbate in the context of SAH?
-2
seizures & cerebral oedema
main symptom of SAH?
Thunderclap headache
very sudden + very painful
signs on examinations?
-1 main one
↓GCS
1st line Ix for all pts?
-2
Urgent CT head & ECG
if CT inconclusive but you still suspect SAH, what is next Ix?
LP
positive result on LP is pt has subarachnoid haemorrhage?
xanthochromia
pt with subarachnoid haemorrhage has LP,
colour of LP?
yellow
why do you get xanthochromia in LP?
haemoglobin breakdown to bilirubin
if LP contraindicated, what is next Ix to confirm subarachnoid haemorrhage?
CT angiogram with injected dye
acute drug given in SAH?
Nimodipine
moa of nimodipine?
what complication does this help in SAH?
blocks L-type Ca2+ channels in blood vessels
vasospasm
conclusive treatment for SAH?
Endovascular coil put in aneurysm
Mx for cerebellar salt wasting syndrome?
-2 things
salty saline, check U+Es daily
definitive treatment for hydrocephalus?
VP shunt
if coil CI what surgery do you for an aneurysm?
Surgically clip the aneurysm via craniotomy
