Rosen & Barkin's 5-Minute Emergency Medicine Consult (144 page)

• Although rare in children, more likely to be giant (>25 mm)
  
• Occur in the posterior circulation
  

DIAGNOSIS

• Commonly asymptomatic before rupture
  
• Sentinel headaches occur in 30–60% of patients before rupture:
  
  • Can be unilateral
    
• Seizures, syncope, or altered level of consciousness
  

• Onset of headache
  
• Family history
  
• Altered mental status
  
• Focal neurologic deficits
  
• Rupture results in subarachnoid hemorrhage:
  
  • Headache: Severe (“worst headache ever”) with sudden onset (“thunderclap”)
    
    • Different from prior headaches
      
    • Classically without focal deficits
      
  • Nuchal rigidity (most common sign) secondary to blood in CSF
    

Compression of adjacent structures may cause neurologic symptoms:

• ACA aneurysms:
  
  • Optic tract: Altitudinal field cut or homonymous hemianopsia
    
  • Optic chiasm: Bitemporal hemianopsia
    
  • Optic nerve: Unilateral amblyopia
    
• Aneurysms at IC–posterior communicating artery junction:
  
  • Oculomotor nerve: Fixed and dilated pupil, ptosis, diplopia, and temporal deviation of eye with inability to turn eye upward, inward, or downward
    
• Aneurysms in cerebral cortex may produce focal deficits including:
  
  • Hemiparesis
    
  • Hemisensory loss
    
  • Visual disturbances
    
  • Aphasia
    
  • Seizures
    

• Complete neurologic examination
  
• Emergent noncontrast head CT scan will diagnose 90–95% of subarachnoid hemorrhages
  
• Lumbar puncture with CSF analysis if CT scan is negative
  

• Coagulation studies
  
• Baseline CBC with platelets and differential
  
• Electrolytes
  
• Renal and liver function tests
  
• Arterial blood gas
  

• CXR for pulmonary edema
  
• 4-vessel cerebral angiography remains gold standard
  
• MRA
  
• Helical CT scanning may be useful in detecting aneurysms >3 mm
  
• Transcranial Doppler US may be useful in detecting vasospasm.
  

Lumbar puncture if suspect aneurysmal leak or rupture with normal head CT

• Neoplasm
  
• Arteriovenous malformation
  
• Optic neuritis
  
• Migraine
  
• Meningitis
  
• Encephalitis
  
• Hypertensive encephalopathy
  
• Hyperglycemia or hypoglycemia
  
• Temporal arteritis
  
• Acute glaucoma
  
• Subdural hematoma
  
• Epidural hematoma
  
• Intracerebral hemorrhage
  
• Thromboembolic stroke
  
• Air embolism
  
• Sinusitis
  

TREATMENT

• Cautions:
  
  • Neurologic examination in the field can be extremely helpful
    
  • Assess:
    
    • Level of consciousness
      
    • Glasgow coma scale score
      
    • Gross motor deficits
      
    • Speech abnormalities
      
    • Gait disturbance
      
    • Facial asymmetry
      
    • Other focal deficits
      
• Patients with subarachnoid hemorrhage may need emergent intubation for rapidly deteriorating level of consciousness
  
• Patients must be transported to a hospital with emergent CT scanning and intensive care unit (ICU)-level treatment
  

• ABCs:
  
  • Supplemental oxygen
    
  • Rapid-sequence intubation may be required for airway protection or for controlled ventilation
    
  • Continuous cardiac monitoring and pulse oximetry
    
• For altered mental status:
  
  • Check blood glucose immediately, give D
    ₅₀
    (if glucose is low)
    
  • Naloxone
    
  • Thiamine
    
• Reversal of anticoagulation
  
• Prevention of acute increases in intracranial pressure from vomiting should be accomplished with antiemetics
  
• Seizures should be managed acutely with IV benzodiazepines and fosphenytoin/phenytoin
  
• Seizure prophylaxis is controversial and not recommended
  

Following initial stabilization, the major goals of early treatment of ruptured or leaking aneurysms are to prevent re-rupture, cerebral vasospasm, and hydrocephalus (see “Subarachnoid Hemorrhage”).

• Optimal timing for angiography and surgery remain controversial, but trend is toward early surgery to decrease incidence of rebleeding and cerebral vasospasm
  
• Early placement of ventriculostomy in appropriate patients may allow for direct intracranial pressure monitoring and often decreases systemic hypertension
  

Aneurysms in children have a high rate of hemorrhage and should be repaired early

• Labetalol: 20–30 mg/min IV bolus, then 40–80 mg q10min max. 300 mg; follow with continuous infusion 0.5–2 mg/min
  
• Nimodipine: 60 mg PO/nasogastric q4h
  
• Ondansetron: 4 mg PO/SL/IV q4h PRN (peds: 0.1 mg/kg IV; max. 4 mg/dose)
  
• Prochlorperazine: 5–10 g IV/IM q6–8h (peds: 0.2 mg/kg/d IM in 3 or 4 div. doses); max. 40 mg/d
  

• Diazepam: 5–10 mg IV q10–15min max., 30 mg (peds: 0.2–0.3 mg/kg q5–10min max. 10 mg)
  
• Docusate sodium: 100 mg PO BID
  
• Fosphenytoin: 15–20 mg/kg phenytoin equivalents (PE) at rate of 100–150 mg/min IV/IM
  
• Hydralazine: 10–20 mg IV q30min
  
• Lorazepam: 2–4 mg IV q15min PRN (peds: 0.03–0.05 mg/kg/dose; max. 4 mg/dose)
  
• Nicardipine: 5 mg/h IV infusion, increase by 2.5 mg/h q5–15min max. 15 mg/h (peds: Dosing unavailable)
  
• Phenytoin: 15–20 mg/kg IV load at max. 50 mg/min; max. 1.5 g (adult and peds); maintenance 4–6 mg/kg/d IV/IM
  

FOLLOW-UP

• Any patient with acute aneurysmal subarachnoid hemorrhage should be admitted, preferably to ICU
  
• Any patient with symptomatic unruptured aneurysm should receive admission and urgent neurosurgical consultation, given high rate of rupture
  

• Patients with incidentally discovered asymptomatic intracranial aneurysms may be discharged with close neurosurgical follow-up
  
• Note that overall risk of rupture is 1–2%/yr and that critical size at which risk for rupture outweighs risk for surgery is controversial (classically 10 mm, but probably in the 4–8-mm range).
  

• Neurosurgery
  
• Neurology
  
• Primary care
  

• CT scan alone is not sufficient to exclude subarachnoid hemorrhage
  
• Vasospasm is typically seen on day 3 after bleed or surgery
  
• Nimodipine can prevent or treat vasospasm but should never be administered IV
  
• Nitroprusside and nitroglycerine should be avoided due to tendency to increase cerebral blood volume and thereby intracranial pressure
  

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• Bederson JB, Connolly ES Jr, Batjer HH, et al. Guidelines for management of aneurysmal subarachnoid hemorrhage: A statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association.
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• Raymond J, Guillemin F, Proust F, et al. Unruptured intracranial aneurysms: A critical review of the International Study of Unruptured Aneurysms (ISUIA) and of appropriate methods to address the clinical problem.
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• Seibert B, Tummala RP, Chow R, et al. Intracranial aneurysms: Review of current treatment options and outcomes.
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• Swadron SP. Pitfalls in the management of headache in the emergency department.
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• Vlak MH, Rinkel GJ, Greebe P, et al. Trigger factors for rupture of intracranial aneurysms in relation to patient and aneurysm characteristics.
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