Rosen & Barkin's 5-Minute Emergency Medicine Consult (682 page)

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Authors: Jeffrey J. Schaider,Adam Z. Barkin,Roger M. Barkin,Philip Shayne,Richard E. Wolfe,Stephen R. Hayden,Peter Rosen

Tags: #Medical, #Emergency Medicine

BOOK: Rosen & Barkin's 5-Minute Emergency Medicine Consult
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Pediatric Considerations
  • Most often due to arteriovenous malformation in children
  • Although rare in children, SAH is a leading cause of pediatric stroke.
ETIOLOGY
  • “Congenital,” saccular, or berry aneurysm rupture (80–90%):
    • Occur at bifurcations of major arteries
    • Incidence increases with age.
    • Aneurysms may be multiple in 20–30%.
  • Nonaneurysmal perimesencephalic hemorrhage (10%)
  • Remaining 5% of causes include:
    • Mycotic (septic) aneurysm due to syphilis or endocarditis
    • Arteriovenous malformations
    • Vertebral or carotid artery dissection
    • Intracranial neoplasm
    • Pituitary apoplexy
  • Severe closed head injury
DIAGNOSIS
SIGNS AND SYMPTOMS
History
  • Classically a severe, sudden headache:
    • Often described as “thunderclap” or “worst headache of life”
    • Headache is often occipital or nuchal, but may be unilateral.
    • Usually develops within seconds and peaks within minutes
    • Distinct from prior headaches
    • Headache often maximal at onset
  • Sentinel headaches and minor bleeding occur in 20–50%:
    • May occur days to weeks prior to presentation and diagnosis
  • Seizures, transient loss of consciousness, or altered level of consciousness occur in more than 50% of patients.
  • Vomiting occurs in 70%.
  • Syncope, diplopia, and seizure are particularly high-risk features for SAH.
Physical-Exam
  • Focal neurologic deficits occur at the same time as the headache in 33% of patients:
    • 3rd cranial nerve (CN III) palsy (the “down and out” eye) occurs in 10–15%.
    • Isolated CN VI palsy or papillary dilation may also occur.
  • Nuchal rigidity develops in 25–70%.
  • Retinal hemorrhage may be the only clue in comatose patient.
ESSENTIAL WORKUP
  • Complete neurologic exam and fundoscopic exam
  • Emergent noncontrast head CT scan:
    • Diagnoses 93–98% of SAH if performed within 12 hr
    • Thin cuts (3 mm) through base of brain improve diagnostic yield.
    • CT is less sensitive after 24 hr or if hemoglobin <10 g/L.
  • Lumbar puncture (LP) and CSF analysis must be performed if CT negative and history suggests possibility of SAH.
Pregnancy Considerations
  • Incidence slightly increased in pregnancy
  • Workup should include CT and LP
DIAGNOSIS TESTS & NTERPRETATION
Lab
  • Baseline CBC and differential
  • Electrolytes, renal function tests
  • Coagulation studies
  • Cardiac markers:
    • Troponin I elevated in 10–40%
  • CSF analysis (see below)
Imaging
  • Chest radiograph for pulmonary edema:
    • Occurs in up to 40% with severe neurologic deficit
  • Traditional gold standard: 4-vessel digital subtraction cerebral angiography
  • Spiral CT angiography:
    • Useful for operative planning
    • Quite sensitive for detection of aneurysms >4 mm, less with smaller aneurysms
  • MR angiography:
    • MRI is less sensitive for hemorrhage
    • Quite sensitive for detection of aneurysms >4 mm, less with smaller aneurysms
  • Transcranial Doppler ultrasound:
    • May be useful in detecting vasospasm.
Diagnostic Procedures/Surgery
  • LP:
    • Presence of erythrocytes in CSF indicates SAH or traumatic tap:
      • If traumatic tap suspected, LP should be performed 1 interspace higher.
      • Diminishing erythrocyte count in successive tubes suggests but does not firmly establish a traumatic tap.
      • Xanthochromia is diagnostic of SAH if performed 12 hr after onset.
    • An elevated opening pressure may indicate SAH, cerebral venous sinus thrombosis, or pseudotumor cerebri.
  • ECG:
    • ST-segment elevation or depression
    • QT prolongation
    • T-wave abnormalities
    • Often mimics ischemia or infarction
    • Symptomatic bradycardia, ventricular tachycardia, and ventricular fibrillation
DIFFERENTIAL DIAGNOSIS
  • Neoplasm
  • Arterial dissection
  • Aneurysm (unruptured)
  • Arteriovenous malformation
  • Migraine
  • Pseudotumor cerebri
  • Meningitis
  • Encephalitis
  • Hypertensive encephalopathy
  • Hyperglycemia or hypoglycemia
  • Temporal arteritis
  • Acute glaucoma
  • Subdural hematoma
  • Epidural hematoma
  • Intracerebral hemorrhage
  • Thromboembolic stroke
  • Sinusitis
  • Seizure disorder
  • Cerebral venous sinus thrombosis
  • Cavernous sinus thrombosis
TREATMENT
PRE HOSPITAL
  • Initial assessment and history:
    • Level of consciousness
    • Glasgow Coma Scale score
    • Gross motor deficits
    • Other focal deficits
  • Patients with SAH may need emergent intubation for rapidly deteriorating level of consciousness.
  • IV access should be established.
  • Provide supplemental oxygen.
  • Monitor cardiac rhythm.
  • Patients should be transported to a hospital with emergent CT and ICU capability.
INITIAL STABILIZATION/THERAPY
  • Manage airway, resuscitate as indicated:
    • Rapid-sequence intubation
    • Pretreat with lidocaine and defasciculating dose of nondepolarizing paralytic to blunt increase in intracranial pressure (ICP) during intubation.
    • Cardiac monitoring and pulse oximetry
    • Establish adequate IV access
  • Obtain urgent neurosurgical consultation
ED TREATMENT/PROCEDURES
  • Prevent rebleeding:
    • Risk of rebleeding highest in the 1st few hours after aneurysmal rupture
  • Manage ICP:
    • Elevate head of bed to 30°.
    • Prevent increases in ICP from vomiting and defecation with antiemetics and stool softeners.
    • Treat increased ICP with controlled ventilation and mannitol.
    • Maintain central venous pressure >8 mm Hg and urine output >50 mL/hr
  • BP control:
    • Balance HTN-induced rebleeding vs. cerebral hypoperfusion
    • Goal mean arterial pressure 100–120 mm Hg, systolic BP <160:
      • Labetalol, hydralazine, nitroprusside, or nicardipine for hypertension
    • Correct hypovolemia:
      • Should start within 96 hr of SAH
      • Treat hypotension with volume expansion.
  • Cerebral vasospasm:
    • May cause secondary ischemia and infarction after SAH:
    • Oral nimodipine improves functional outcome:
      • Discuss with neurosurgeon prior to administration
    • Monitor with transcranial Doppler.
  • Adequately treat pain.
  • Seizures:
    • Manage with IV benzodiazepine
    • Consider prophylactic anticonvulsants in immediate posthemorrhagic period
  • Correct temperature, electrolyte, glucose, or pH abnormalities.
  • Treat coagulopathy, thrombocytopenia, and severe anemia.
  • Monitor for and correct pulmonary edema and cardiac arrhythmias.
  • Antifibrinolytic therapies:
    • Discuss with neurosurgeon prior to initiation
    • Consider administration immediately after aneurysmal rupture in patients at high risk of rebleeding when this is combined with treatment of aneurysm and monitoring for hypotension.
  • When patient is stable, expedited transfer to hospital with neurosurgical capabilities is mandatory.
MEDICATION
  • Diazepam: 5–10 mg (peds: 0.2–0.3 mg/kg) IV/IM q10–1min PRN; max. 30 mg (peds: 10 mg)
  • Fentanyl: 1–3 μg/kg (adults and peds) IV q1–4h PRN
  • Fosphenytoin: 15–20 phenytoin equivalents (PE) per kg (adults and peds) IV × 1; maintenance 4–6 mg/kg/d IV
  • Hydralazine: 10–20 mg (peds: 0.1–0.5 mg/kg IV) q30min–4h PRN
  • Labetalol: 20 mg IV bolus, then 40–80 mg q10min; max. 300 mg; follow with IV continuous infusion 0.5–2 mg/min (peds: 0.4–1 mg/kg/h IV continuous infusion; max. 3 mg/kg/h)
  • Lidocaine: 1–1.5 mg/kg IV × 1 (adults and peds)
  • Lorazepam: 2–4 mg (peds: 0.03–0.05 mg/kg/dose; max. 4 mg/dose) IV q15min PRN
  • Midazolam: 1–2 mg (peds: 0.15 mg/kg IV × 1) IV q10min PRN
  • Morphine: 2–10 mg (peds: 0.05–0.2 mg/kg IV) q2–4h PRN
  • Nicardipine: 5–15 mg/h IV continuous infusion (peds: Safety not established)
  • Nimodipine: 60 mg PO/NGT q4h; (peds: Safety not established)
  • Nitroprusside: 0.25–10 μg/kg/min IV continuous infusion (adults and peds)
  • Ondansetron: 4–8 mg (peds: 0.1–0.15 mg/kg max. 4 mg) PO/IM/IV TID PRN
  • Phenytoin: 15–20 mg/kg IV load at max. 50 mg/min; max. 1.5 g; maintenance 4–6 mg/kg/d IV; (adult and pediatric)
  • Promethazine: 12.5–25 mg (peds >2 yr old: 0.25–1 mg/kg; max. 25 mg/dose) PO/IM/IV q4–6h PRN
SURGERY/OTHER PROCEDURES
  • Per neurosurgical consultant
  • Early operative or endovascular intervention may prevent vasospasm and improve outcome.
FOLLOW-UP

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