Archive | December, 2016

Subarachnoid Hemorrhage (SAH) – quick review

19 Dec

submitted by Christina Brown, M.D.

Definition – Bleeding into the subarachnoid 300px-subarachnoidpspace and CSF:

  • Spontaneous – Most often results from cerebral aneurysm rupture.
  • Traumatic – Represents severe head injury.

 

Epidemiology – Although rare, SAH is a leading cause of pediatric stroke.

 

History

  • Headache is often occipital or nuchal, but may be unilateral.
  • Distinct from prior headaches.
  • Usually develops within seconds and peaks within minutes
  • Maximal at onset.
  • Can be associated w/ seizures, transient loss of consciousness, or altered level of consciousness occur in more than 50% of patients.
  • Vomiting occurs in 70%.
  • High risk features – Syncope, diplopia, and seizure.

 

Physical Exam

  • 33% – Focal neurologic deficits occur at the same time as the headache
  • 10-15% – Third cranial nerve (CN III) palsy (“down and out”)
  • 25%–70% – Nuchal rigidity.
  • Isolated CN VI palsy or papillary dilation may also occur.
  • Retinal hemorrhage may be only clue in comatose patient.

 

Work Up:

  • Emergent noncontrast head CT scan:
    • Diagnoses 93%–98% of SAH if performed within 12 hrs of onset.
    • 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.

Diagnostic Procedures

  • Lumbar puncture:
    • Presence of erythrocytes in CSF indicates SAH or traumatic tap:
      • If traumatic tap suspected, LP should be performed one inter-space higher.
      • Xanthochromia is diagnostic of SAH if performed 12 hours after onset.
    • An elevated opening pressure may indicate SAH, cerebral venous sinus thrombosis, or pseudotumor cerebri.

PRE-HOSPITAL

  • Manage airway, resuscitate as indicated:
    • Rapid sequence intubation

ED TREATMENT/PROCEDURES

  • Manage intracranial pressure (ICP):
    • Elevate head of bed to 30 degrees.
    • Consider pretreatment with lidocaine and defasciculating dose of nondepolarizing paralytic to blunt increase in intracranial pressure (ICP) during intubation.
    • Prevent increases in ICP from vomiting and defecation with antiemetics and stool softeners.
  • Blood pressure (BP) control:
    • Balance HTN-induced rebleeding vs cerebral hypoperfusion
    • Goal systolic BP <160, mean goal between 100-120.
      • Nicardipine, Labetalol
    • Correct hypovolemia:
      • Treat hypotension with volume expansion.
  • Seizure prophylaxis
  • Transfer to facility with neurosurgical capabilities.

 

DISPOSITION

  • All patients with SAH should be admitted to an ICU.
  • Patients with negative CT findings and equivocal LP findings should be admitted.

 

References:

  1. Edlow J A, Malek A M, and Ogilvy C S.: Aneurysmal subarachnoid hemorrhage: Update for emergency physicians. J Emerg Med.2008; 34(3):237–251.
  2. Schaider, J. & Barkin, R. & Hayden, S. & Wolfe, R. & Barkin, A. & Shayne, P. & Rosen, P. (2011). Subarachnoid Hemorrhage. Rosen and Barkin’s 5 minute Emergency Medicine Consult.
  3. Armin S S, Colohan A R, and Zhang J H.: Traumatic subarachnoid hemorrhage: Our current understanding and its evolution over the past half century. Neurol Res.2006; 28(4):445–452.
  4. Bederson J B and ConnollyES Jr. et al.: Guidelines for the management of aneurysmal subarachnoid hemorrhage: A statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. 2009; 40:994–1025.
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Epidural Hematoma (quick review)

2 Dec

submitted by Christina Brown, M.D.

37860tn

Definition – Inward bending of cavarum causes bleeding when dura separates from skull:

  • Middle meningeal artery is involved in bleed >50% of time.
  • Meningeal vein is involved in 1/3.

 

Associations 

  • Mortality is 12% and is related to preoperative condition.  
  • Skull fracture is associated in 75% of cases, less commonly in children. 

 

Pediatric Considerations

  • Head injury is the most common cause of death and acquired disability in childhood.  
  • Bleeding is more likely to be venous.
  • Good outcome in 95% of children <5 yr

 

History

  • LOC: 85% will have at some point in course:
  • Only 11–30% will have a lucid interval.

 

MORE Pediatric Considerations

  • Many times the only clinical sign is drop in hematocrit (Hct) of 40% in infants.
  • Bulging fontanel with vomiting, seizures, or lethargy also suggest EDH in infants.
  • Less than 50% of children have LOC at time of injury.
  • Posterior fossa lesions are seen more commonly in children.

 

Physical Exam

  • Pupillary dilation:  Usually on same side as lesion (90%)
  • Hemiparesis >1/3:  Usually on opposite side from lesion (80%)

 

Imaging (CT Head)

  • Lenticular, biconvex hematoma with smooth borders may be seen.
  • Mixed density lesion may indicate active bleeding.
  • Most commonly seen in temporal parietal region

 

 

 

Initial Stabilization/Therapy

  • Head-injured patients have 25% improved mortality when triaged to regional trauma centers
  • Prevent hypoxia and hypotension:
    • Rapid-sequence intubation for signs of deterioration or increased intracranial pressure (ICP)
  • Perform rapid neurologic assessment

 

ED Management

Early surgical intervention (<4 hr) in comatose patients with EDH.  Nonsurgical intervention in asymptomatic patients is associated with high rate of deterioration; >30% require surgical intervention.

Control ICP

  • Prevent pain, posturing, and increased respiratory effort
  • Elevate head of bed 15–20% after adequate fluid resuscitation.
  • Controlled ventilation to PCO2 of 35–40 mm Hg (Avoid hyperventilation unless signs of brain herniation are present).

Continuous end tidal CO2 monitoring

Arterial line placement for close monitoring of MAP, PO2, PCO2

Treat HTN:  Nicardipine, Labetalol

Treat hyperglycemia if present: Associated with increased lactic acidosis and mortality in patients with TBI

Treat and prevent seizures: diazepam, levitiracetam, etc.

and once again, Early (neuro)surgical intervention


 References:

  1. Schaider, J. & Barkin, R. & Hayden, S. & Wolfe, R. & Barkin, A. & Shayne, P. & Rosen, P. (2011). Epidural Hematoma, Rosen & Barkin’s 5-Minute Emergency Medicine Consult.
  2. Bullock M R et al.: Surgical management of traumatic brain injury. Neurosurgery.2006; 58(3 Suppl):S16–S24.
  3. Marion D M.: Epidural hematoma.  In: Bradley W G: ed. Neurology in Clinical Practice,5th ed.Elsevier;2008: 54 A,B:1083–1114.
  4. Vincent J L and Berre J.: Primer on medical management of severe brain injury. Crit Care Med.2005; 33(6):1392–1399.
  5. Huh J W and Raghupathi R.: New concepts of treatment in pediatric traumatic brain injury. Anesth Clin.2009: 27(2):213–240.
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