Subarachnoid haemorrhage

Question 1

Why is subarachnoid haemorrhage important?

Answer 1

• 5% of all strokes
• high level of mortality and morbidity
• 1/3 of survivors are dependent on carers
  1/2 have life-changing cognitive deficits

Question 2

What are the causes of subarachnoid haemorrhage?

Answer 2

1. Aneurysmal (ACOM, MCA bifurcation, PCOM)
2. AVMs
3. Trauma
4. Moyamoya disease

Question 3

What are the risk factors for SAH?

Answer 3

1. age 40-60 years
2. Hypertension
3. Atherosclerosis
4. Smoking
5. Alcohol abuse
6. Cocaine use
7. Inherited conditions: Autosomal dominant polycystic kidney disease, collagen vascular disease.

Question 4

How does SAH present?

Answer 4

• Classical thunderclap headache - possible sentinel bleed headache
• Nausea and vomiting
• Altered consciousness
• Neck stiffness
• Photophobia
• Coma
• Seizures

Question 5

How is SAH diagnosed?

Answer 5

1. Unenhanced CT
2. Lumbar puncture (after 12 hours symptom onset) for xanthochromia
3. Digital subtraction CT angiography
4. Cerebral angiography

Question 6

How is SAH graded?

Answer 6

Clinically or radiologically

Clinically - WFNS:
1 - GCS 15 and no motor defect
2 - GCS 13-14 and no motor deficit
3 - GCS 13-14 with motor deficit
4 - GCS 7-12
5 - GCS <7

Radiologically - Fisher CT criteria
1 - no blood seen
2 - blood layers <1mm thick
3 - Localised clots or blood layers >1mm
4 - Non-subarachnoid blood or intraventricular involvement

Question 7

What is the immediate management of SAH?

Answer 7

ABCDE approach to prevent secondary brain injury and focuses on neuroprotection.

A&B - control of airway in reduced consciousness and control of ventilation aiming pCO2 4.5-5.0 and pO2 >10
C - Optimise BP to prevent ischaemia from raised ICP or worsen bleed - target BP 80110. Nimodipine to prevent delayed cerebral ischaemia/vasospasm
D - seizure control and prevention of raised ICP, frequent pupil monitoring. Prompt CT scan.
E - Normothermia, normoglycemia. D/W neurosurgical centre.

Question 8

What definitive management options are there for aneurysmal SAH?

Answer 8

• Protective measures against secondary brain injury and delayed cerebral ischaemia.
• Clipping or coiling of an aneurysm (ISAT trial 2002 - coiling had lower death and dependence but higher re-bleed risk).
• prevention and treatment of other non-neurological conditions/complications

Question 9

What is delayed cerebral ischaemia?

Answer 9

• Neurological deterioration related to ischaemia (unrelated to treatment of the aneurysm) that persists for one hour and has no other cause.
• May be caused by vasospasm:
  i) diagnosed by angiography or trans cranial doppler (Lindegaard ratio >3).
  ii) treated with:
• nimodipine (Cochrane review found benefit in death and dependence)
• Triple H therapy - only hypertension really used now
• Endovascular interventions: angioplasty or vascodilator therapy

Question 10

What are the complications following SAH and how are they managed?

Answer 10

Neurological:

1. Obstructive hydrocephalus -> EVD
2. Re-bleeding ->Re-coiling/clipping
3. Seizures -> Exclude non-convulsive status, manage with AEDs.

Non-neurological:

• Respiratory: VAP/aspiration/ARDS/neurogenic pulmonary oedema
• CVS: Neurogenic stunned myocardium due NA release/Takotsubo cardiomyopathy/VTE
• Metabolic: fever, hyperglycaemia/hypoglycaemia/SIADH/CSWS/DI