Subarachnoid Haemorrhage

Question 1

What is the most common type of SAH?

Answer 1

Aneurysmal - local dilation of the artery

Question 2

Describe the aetiology of an aneurysmal SAH.

Answer 2

Incidence - 8/100,000
Age of presentation: 40-60
3% of all strokes

Question 3

What causes aneurysm formation in an aneurysmal SAH?

Answer 3

Haemodynamic stress
Extensive inflammatory and immunological reactions are common in unruptured intracranial aneurysms and may be related to aneurysm formation and rupture

Question 4

Describe formation of aneurysms.

Answer 4

Increased haemodynamic stress on blood vessels normally involves equal outward vascular growth.
In maladaptive vascular remodelling, there is only focal activation of growth.
- only a small area of the blood vessel increases in size
- an aneurysm

Question 5

Which arteries cause SAH when they rupture?

Answer 5

Cerebral arteries

• anterior
• middle
• posterior

Question 6

What are the non-aneurysmal causes of an SAH?

Answer 6

AVM - arteriovenous malformation
Neoplasia 
No identifiable cause
- angiogram negative 
- follow a benign course

Question 7

What are the predisposing risk factors for aneurysmal SAH?

Answer 7

Smoking
Female sex
Hypertension
Positive family history
ADPCK (polycystic kidney disease)
Ehlers Danlos (connective tissue syndrome)
Coarctation of the aorta

Question 8

What history would you expect from someone with a SAH?

Answer 8

Sudden onset, high intensity (thunderclap) headache
Loss of consciousness
Seizures
Visual, speech and limb disturbances
Sentinel headache 
- headache precedes SAH by days/weeks
- small SAH bleed

Question 9

What do you expect to see on clinical examination if someone has a SAH?

Answer 9

Photophobia 
Meningism
Subhyaloid haemorrhages
Vitreous heamorrhage
Speech and limb disturbance 
Pulmonary oedema

Question 10

Describe the WFNS grading system in SAH prognosis.

Answer 10

Grade 1 - GCS 15
Grade 2 - GCS 13/14 with no neurological deficit
Grade 3 - GCS 13/14 with neurological deficit
Grade 4 - GCS 7/12
Grade 5 - GCS 3/6

Question 11

Why do you need to do a CT on someone with an SAH?

Answer 11

Confirms the diagnosis and shows location of the aneurysm
Identifies complications
- infarction
- haematoma
- hydrocephalus (CSF accumulation)
Allows estimation of prognosis with the Fisher Grade
- predicts risk of vasospasm
- the thicker the haematoma, the worse the prognosis

Question 12

What investigations are performed if someone has a suspected SAH?

Answer 12

CT
Lumbar Puncture 
CTA
MRA
DSA (digital subtraction angiography) 
- stroke, diabetics

Question 13

What do you look for in an LP if someone has an SAH?

Answer 13

Used when patients have a negtive CT scan
Xanthochromia
- bilirubin in the CSF (yellowing)

Question 14

Aside from imaging and xanthochromia, what changes would you see on investigations if a person has an SAH?

Answer 14

Hyponatraemia 
ECG changes 
Elevated troponin levels
Echo - tako tsubo cardiomyopathy 
Easy to mistake for an MI

Question 15

How is a person with an SAH immediately treated?

Answer 15

Bed rest
Fluids - 3L of normal saline
Anti-embolic stockings
Nimodipine
- calcium channel blocker
- has a neuro-protective effect
Analgesia 
Doppler studies

Question 16

What are the three long term methods of management of an SAH?

Answer 16

Surgical clipping
Endovascular (coils, stents and glue)
Conservative

Question 17

How are surgical clippings of aneurysms performed?

Answer 17

Clips are placed along the base of the aneurysm, preventing flow of blood into it
- no longer under stress and goes down
- excluding the aneurysm
- be careful to to clip the perforating arteries that arise around the aneurysm
CTA performed post-clipping to ensure the clips are in place

Question 18

How are endovascular management of aneurysms performed?

Answer 18

Electrically induced thrombosis within the aneursym
Detachable coils to fill and exclude the aneurysm
Stent to divert the blood and allow healing (e.g. WEB device)

Question 19

Which aneurysm requires fenestrated clips during surgical clipping treatment?

Answer 19

Anterior communicating artery aneurysm

Question 20

What complications can occur post aneurysm?

Answer 20

Re-haemorrhage
Delayed ischaemia 
Hydrocephalus 
Hyponatraemia
ECG changes
- left ventricular failure (tako-tsubo cardiomyopathy)
Lower respiratory tract infection
UTI
Pulmonary embolism

Question 21

When is risk of re-haemorrhage highest?

Answer 21

Immediately after initial bleed
In poor grade patients (lower GCS)
Larger aneurysms
Repair isn’t quick enough

Question 22

If a person develops hydrocephalus, how can they be managed?

Answer 22

Temporarily
- LP
- spinal drain
A shunt to allow CSF drainage can be used

Question 23

What complication is most common after occlusion of the aneurysm?

Answer 23

Delayed ischaemia

Question 24

What causes delayed ischaemia?

Answer 24

Angiographic spasm

- microcirculation shutting down due to release of blood products at the time of haemorrhage

Question 25

How can you recognise delayed ischaemia?

Answer 25

Progressive deterioration in loss of consciousness | - associated with a new deficit

Question 26

How is delayed ischaemia managed?

Answer 26

``` Fluid management - colloid infusions Nimodipine Inotropes - increases bp to force the blood through the system Angioplasty (balloon angioplasty) ```

Question 27

Name some of the causes of hyponatraemia after SAH.

Answer 27

Cerebral salt wasting syndrome - blood around the brain causes the patient to leach sodium and loose water SIADH - less common - increased water retention Can flip from one to the other, affecting treatment

Question 28

How is a patient with hyponatraemia managed?

Answer 28

``` Establish the volume status - decreased in CSWS - increased in SIADH CSWS treatement - Fludrocortisone - Hypertonic saline ```

Question 29

How does SAH cause cardiopulmonary complications?

Answer 29

Bleeding and pressure release cause cause widespread catecholamine release This can damage the heart

Question 30

What heart problems are associated with SAH?

Answer 30

``` Troponin elevation Arrythmias Wall motion Sudden death Tako-tsubo cardiomyopathy - clot formation - poor pumping ```

Question 31

How do seizures after SAH occur?

Answer 31

Blood around the brain irritates the neurons Often a manifestation of re-rupture Can be given anti-convulsants

Question 32

Why is DVT prophylaxis needed after SAH?

Answer 32

Patients lie prone in bed SAH induces a prothrombotic state Difficult because the patient is also bleeding - anti-thrombotic agents are being used - safest to use sequential compression devices initially (after the aneurysm is secured)