Subarachnoid Hemorrhage

1. See Also
   1. Cerebral Aneurysm
   2. Neurovascular Anatomy
2. Symptoms
   1. Sudden onset of "Worst Headache of my life"
   2. "Thunder-Clap" Headache
   3. Headache reaches maximum intensity in minutes
   4. Continued unrelenting Headache
   5. May be accompanied by Nausea and Vomiting
   6. Initial herald bleed (sentinel hemorrhage)
      1. Warning leak of small volume
      2. May precede full aneurysm rupture in >50% of cases
3. Signs
   1. Identify subtle focal neurologic changes
      1. Anterior Cerebral Artery CVA
      2. Middle Cerebral Artery CVA
      3. Vertebro-Basilar CVA
      4. Posterior Cerebral Artery CVA
      5. Posterior Inferior Cerebellar Artery CVA
   2. Brief Loss of consciousness at Headache onset
   3. Meningismus (e.g. Nuchal Rigidity)
   4. Ocular Motor Nerve palsy
   5. Papilledema
4. Course
   1. Missed Subarachnoid Hemorrhage
      1. Rebleeding risk: 50% in 2 weeks
      2. Increased mortality risk
5. Diagnosis
   1. CT Head without contrast
      1. Overall misses 5% of Subarachnoid Hemorrhage
      2. However third generation CT scans read by a qualified radiologist are extremely accurate when performed early after Headache
         1. CT Head within 6 hours of acute onset severe Headache in a neurologically intact patient was 100% sensitive and specific
            1. Perry (2011) BMJ 343: d4277
         2. Reviews of this paper however suggest flaws (inconsistent follow-up and LP protocol)
            1. Not recommended as justification to not perform Lumbar Puncture after negative CT Head in high suspicion cases
            2. Newman (2012) EM:RAP 12(3): 6-7
      3. Test Sensitivity decreases within days of event
         1. Day 3: 95% Test Sensitivity
         2. Day 5: 85% Test Sensitivity
         3. Day 7: 50% Test Sensitivity
         4. Day 14: 30% Test Sensitivity
   2. Lumbar Puncture
      1. Indicated for high suspicion but negative CT Head
      2. CSF RBCs: 1000-2000 within 2-12 hours after Headache
      3. CSF Leukocytes and protein may also be increased
      4. Xanthochromia in centrifuged Cerebrospinal fluid
6. Management
   1. Neurosurgery Consultation
      1. Endovascular coiling may be preferred over surgery
         1. Higher one year survival: 23.7% versus 30.6%
         2. Shorter delay to procedure: 1.1 versus 1.7 days
         3. (2002) Lancet 360:1267-74
   2. Head of Bed at 30 degrees
   3. Prevent vasospasm with good hydration
   4. Use Nipride to keep Systolic Blood Pressure <130 mmHg
   5. Dilantin for Seizure Prophylaxis
   6. Minimize cough with codeine
   7. Minimize Pain with Morphine
   8. Minimize Constipation
   9. If High Intracerebral Pressure or "Blown Pupil"
      1. Titrate Mannitol (start at 1 gram/kg)
         1. Check Serum Osmolality (keep 305-315)
         2. Check Serum Sodium q6h (keep >140)
      2. Hyperventilate to PCO2 of 30-35 mmHg