Subarachnoid Haemorrhage

Question 1

EPIDEMIOLOGY

Answer 1

• Incidence 6-20 per 100 000 per year
• Rare <20y, most freq. btw 40-60y
• 85% due to berry aneurysm

Question 2

CLINICAL FEATURES

Answer 2

1. Sudden, severe headache
   - ‘hit by bat’
   - mostly generalised headache
2. hypert.(50%)
3. Neck stiffness(66%)
4. Death before reaching hosp.(1 in 6)
5. Focal signs(40%)
6. vomiting
7. transient LOC
8. 3rd nerve palsy
   - PCA aneurysm. 3rd nerve palsies involving pupil are due to this till proven otherwise
   - uncal herniation
9. 6th nerve palsy
   - false localising sign of hydrocephalus
10. Opthalmoscopy –> subhyaloid haemorrhage
11. Preceding sudden,severe headache(33%)

Question 3

DDX

Answer 3

1. Thunderclap headache
   - X loss of consciousness, focal neurological signs
   - can be situational eg on exercise/sexual intercourse
   - after SAH ruled out
2. Meningitis
   - headache, fever, neck stiffness, vomiting
3. Coma

Question 4

INVESTIGATIONS:

1. To confirm SAH
2. To find source of bleed

Answer 4

1. a) CT scan. 95% positive within 24h, 67% positive by 72h
   b) if CT negative, LP, delay till 12h(SIGN)
   - Xanthochromia, confirm w spectrophotometry.
2. CT/MR angiography

Question 5

COMPLICATIONS

Answer 5

1. Rebleeding from aneurysm(30%)
2. Cerebral ischemia
3. Obstructive hydrocephalus(from blood in ventricles)
   * Px with loss of consciousness/focal neurological signs.1-3 distinguished through repeat CT scanning

Occassionally:

4. Hyponatraemia
5. Arrythmias
6. Neurogenic pulmonary oedema

Complications of bed rest:

7. DVT
8. aspiration pneumonia
9. basal pneumonia

Question 6

MANAGEMENT

Answer 6

1. Admit to ICU
2. Frequently monitor neurological obs, GCS, BP, pulse
3. Endovascular coiling/surgical clipping.
4. CCB for vasospasm prophylaxis
   - nimlodipine 60 mg PO every 4h for 21d.
5. Stool softeners to prev. straining.
6. Adjuncts:
   a) antitussive for cough
   b) opioid analgesic for headache
   c) coagulopathy correction
   d) sodium replacement
   - rapid correction can precipitate central pontine myelinolysis
   - do not exceed correction rate of 12 mEq/24h

Question 7

ADDITIONAL

Answer 7

1. Unruptured aneurysms
   - risk of bleeding=0.5% per year if >10 mm. 0.05% per year if smaller.
   - management option depends on life expectancy, operative risk and patient preference
2. Giant aneurysm
   - Endovascular techniques best suited