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Subarachnoid haaeenmorrge

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subarachnoid haemorrhage symptoms emergency diagnosis treatment guideline NHS

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https://www.nice.org.uk/guidance/ng228/chapter/Recommendatio…

Subarachnoid haemorrhage (SAH)

SAH is bleeding into the space between the brain and its covering membranes. It is a life-threatening form of stroke. A spontaneous SAH is most often due to rupture of a cerebral aneurysm, usually around the circle of Willis. - Bailey and Love's Short Practice of Surgery, p. 730.
Common sites of cerebral aneurysms in the circle of Willis

Classic presentation

  • Sudden, maximal-at-onset, severe "thunderclap" headache
  • Neck pain or stiffness
  • Nausea and vomiting
  • Photophobia
  • Collapse, reduced consciousness, seizures
  • Sometimes focal deficits: weakness, facial droop, speech or visual problems
A sudden severe headache requires emergency assessment even if it improves. The NHS emergency advice advises calling emergency services rather than driving to hospital.

Causes and risk factors

  • Ruptured berry (saccular) aneurysm, the commonest non-traumatic cause
  • Arteriovenous malformation
  • Head trauma
  • Less commonly: arterial dissection, infection-related aneurysm, or drug-related vasculopathy
Risk factors include hypertension, smoking, cocaine use, family history, and some inherited disorders such as autosomal dominant polycystic kidney disease and Ehlers-Danlos syndrome. - Bailey and Love's Short Practice of Surgery, p. 730.

Diagnosis

  1. Urgent non-contrast CT head: demonstrates acute blood in the basal cisterns/sulci. CT is most sensitive soon after onset. - Grainger & Allison's Diagnostic Radiology, pp. 1457-1458.
  2. If CT is negative but suspicion remains:
    • CT performed within 6 hours and formally reported negative: lumbar puncture is not routinely recommended.
    • CT performed more than 6 hours after onset and negative: consider lumbar puncture after at least 12 hours to test for bilirubin/xanthochromia. See NICE diagnostic recommendations.
  3. CT angiography or catheter angiography identifies the aneurysm and guides treatment.

Management principles

  • Admit urgently to a specialist neurosurgical/neurovascular centre.
  • Stabilise airway, breathing, circulation; manage pain, nausea, blood pressure, and complications.
  • Nimodipine is used in confirmed aneurysmal SAH to reduce delayed cerebral ischaemia from vasospasm. NICE recommends enteral nimodipine where appropriate.
  • Secure the ruptured aneurysm early by:
    • Endovascular coiling, or
    • Neurosurgical clipping
  • Monitor and treat rebleeding, hydrocephalus, seizures, vasospasm/delayed cerebral ischaemia, electrolyte abnormalities, and cardiac complications.

Important complications

  • Early rebleeding, especially within the first 24 hours
  • Cerebral vasospasm and delayed cerebral ischaemia, usually several days after the bleed
  • Hydrocephalus
  • Seizures
  • Long-term cognitive, mood, fatigue, and neurological effects
If this refers to a real person with a sudden severe headache, collapse, seizure, confusion, or new weakness, seek emergency care now.
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