Subarachnoid Haemorrhage

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Clinical Description

Bleeding into the subarachnoid space, most commonly due to the rupture of a vascular aneurysm. Diagnosis is confirmed preferably by neurological imaging and, when this is not available, urgently refer this patient as lumbar puncture (which is done to demonstrate xanthochromia) may lead to cerebral herniation.

Causes

  • Rupture of saccular aneurysms (80%), AVMs (15%)

Risk Factors

  • Smoking, Hypertension, Alcohol, Bleeding diathesis, Mycotic aneurysms, Family history

Clinical FeaturesSIGNS AND SYMPTOMS

  • Sudden, severe occipital headache, Collapse, Meningism: neck stiffness, nauseas and vomiting, photophobia, Seizures, Drowsiness → coma

INVESTIGATIONS

  • Brain CT 
  • Detects >90% of SAH within first 48hrs.
  • Lumbar Puncture
  • If CT negative and no contraindications >12h after start of headache      Xanthochromia due to breakdown of bilirubin

Treatment NON-PHARMACOLOGICAL

  • Frequent neurological observations: pupils, GCS, BP
  • Maintain cerebral perfusion pressure (CPP): keep SBP >160mmHg.
  • Endovascular coiling (preferable to surgical clipping)

PHARMACOLOGICAL

  • Analgesia if level of consciousness is not impaired:
    • Paracetamol, oral, 1 g q4-6h when required to a maximum of 4 doses per 24 hours.
    • Avoid NSAIDs.
  • If no response:
    • Morphine, IV, 1-2 mg/minute to a maximum total dose of 10 mg. Dilute 10 mg up to 10 ml in sodium chloride solution 0.9%. This may be repeated q4h
  • In patients with grades 1 to 3 impairment of consciousness level while waiting for transfer to neurosurgical facility and in consultation with neurosurgeon:
    • Give Nimodipine, oral, 60 mg q4h for 21 days.

Complications

  • Rebleeding:
    • 20% Commonest cause of mortality
  • Cerebral Ischemia
    • Due to vasospasm
    • Commonest cause of morbidity
  • Hydrocephalus
    • Due to blockage of arachnoid granulations     
    • May require ventricular or lumbar drain.

When to refer

  • All patients with minimal impairment of consciousness level for possible angiography and appropriate neurosurgical management. Patients initially deemed unsuitable for further investigation, may be referred at a later stage, should their condition improve.
  • For neurological imaging: patients in whom the diagnosis must be confirmed radiologically and where a lumbar puncture may be considered hazardous.
  • All patients with functional neurological deficits to be referred for Medical Rehabilitation services.