Subarachnoid hemorrhage

Definition

Life-threatening intracerebral hemorrhage occurring below the arachnoid membrane

Incidence of 10-14 per 100,000 persons / year
- Accounts for 3-5% of all strokes
More common in women
About 1% of population has an asymptomatic intracranial aneurysm

I -- no blood
II -- diffuse deposition of SAH without clots or layers of blood >1mm
III -- localized clots and/or vertical layers of blood 1mm or > thickness
IV -- diffuse or no subarachnoid blood but intracerebral or intraventricular clots

Trauma (most common)
Intracranial aneurysms (80% of spontaneous SAH)
- AComm most common
- PComm second-most common
Non-aneurysmal perimesencephalic hemorrhage
Arteriovenous malformations
Arterial dissection and CNS vasculitis
Coagulopathies
Drug-induced
- Cocaines
- Amphetamines
Pituitary apoplexy

"Thunderclap headache"/"worst headache of my life"
- Peaks in minutes
- May have occurred with exertion (50%) or in sleep (15-30%)
Soon after onset
- +/- nausea & vomiting
- +/- transient loss of consciousness or weakness
Sentinel bleed with warning headache in 20-50%
May present with seizures
Other signs
Reduced of altered level of consciousness (30%)
Intraocular hemorrhage (20-40%)
- Presence of subhyaloid hemorrhage pathognomonic
Cranial nerve palsies
- Especially oculomotor (PComm aneurysm)
Meningismus, after a few hours (from blood breakdown)
Focal deficits
- Hemiparesis possible if intracerebral clot (e.g. MCA)
Systemic features
- Fever, hypertension, arrhythmias/EKG changes
Paramesencephalic subarachnoid hemorrhage
- More benign, small aneurysm that self-resolves
- Two negative angiograms separated by 10-14 days

Initial management
- Stabilize patient (ABCs)
- Send for CT head +/- LP to confirm diagnosis
- Consult neurosurgery
Stabilization
- Ensure IV access
- Manage airway, with intubation if necessary
- Cardiac monitoring (arrhythmias are common)
- Bed rest, elevate head of bed to 30 degrees
- Pneumatic compression devices for thromboembolism prophylaxis
- Adequate fluid intake
- Blood pressure control
  - Goal: SBP <160 (now <140) or less and MAP <110
  - Be aggressive, using IV labetalol, hydralazine, enalapril
Vasospasm prophylaxis: nimodipine 60mg po q4h for 21 days
Treat coagulopathies
After transfer to tertiary centre
- Serial CT or CT angiogram
- Angiogram when available
- Surgical clipping or endovascular coiling by neurosurgery or interventional radiology

Vasospasm
- Onset at 3-5 days, peak at 1-2 weeks
- Evaluate with transcranial dopplers +/- angiogram, although clinical diagnosis more important that radiological
- Prophylaxis with nimodipine
- Hyperdynamic therapy (3H)
  - Hyperhydration (150-200cc/h)
  - Hypertension (inotropes if necessary)
  - Hemodilution
  - Only after aneurysm is secure
Hydrocephalus
- May need VP shunt
EKG changes
- Changes to ST, T, and U
- Prolonged QT (60%)
- Arrhythmias
Rebleeding
- 50% re-reupture within 6 months
- About 2%/day up to 15-20% at 14 days
- Often fatal
Seizures
- Can prophylax with phenytoin for 1 week
Hyponatrmia
- SIADH or cerebral salt wasting (atrial natriuretic protein), depending on volume status
- Avoid hypotonic fluids

10% died before hospital, usually from arrhythmias or acute hydrocephalus
10% die in first 24h, usually from early rebleeding
Long-term survival less than 50%
- 1/2 will never return to previous quality of life