Synopsis
Recognise aneurysmal subarachnoid haemorrhage, apply the time-dependent CT and lumbar-puncture diagnostic pathway, and coordinate aneurysm securing and prevention of rebleeding, hydrocephalus and delayed cerebral ischaemia.
- Suspect subarachnoid haemorrhage when a new severe headache reaches peak intensity within minutes, especially with neck stiffness, vomiting, photophobia, collapse, seizure or focal deficit.
- A normal neurological examination does not exclude SAH; many alert patients have only headache at presentation, and a sentinel headache may precede a larger aneurysmal bleed.
- Obtain urgent non-contrast CT brain, document the interval from onset and ensure expert interpretation because sensitivity is highest in the first 6 hours and decreases thereafter.
Key red flags
Reduced consciousness, airway compromise, recurrent seizure or cardiorespiratory instability requires immediate resuscitation and neurocritical-care involvement.
Investigation priorities
Detect subarachnoid blood, hydrocephalus, intraventricular or intracerebral extension and early mass effect.
Management branches
A patient has a new severe headache reaching maximum intensity within minutes.
- Assess airway, consciousness, focal neurology, pupils, meningism, seizure, pressure and antithrombotic exposure and treat immediate instability.
- Arrange urgent non-contrast CT and record exact onset and scan times, providing the radiologist with the suspected SAH diagnosis.
Key medicines
NimodipineGive 60 mg orally or through an enteral tube every 4 hours, usually for 21 days from haemorrhage, following the neuroscience protocol; modify dosing if hypotension limits treatment.
AnalgesiaUse regular paracetamol within the individual maximum and carefully titrated additional analgesia from the neuroscience protocol while preserving reliable neurological assessment.