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24 Cards in this Set
- Front
- Back
What is the primary goal of a patient with TBI and what are 2 ways to accomplish this?
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Prevent secondary brain injury --
1. maintain adequate blood pressure to sufficiently perfuse the brain 2. maintain adequate oxygenation |
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What are the 2 classic findings in uncal herniation?
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1. Ipsilateral pupillary dilation (compression of CN III PS fibers in the midbrain at the tentorial notch)
2. contralateral hemiparesis (compression of corticospinal tract as it crosses at foramen magnum) |
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What is the monro-kellie doctrine?
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Because skull is rigid, it has a fixed volume. Therefore, mass lesions can initially force venous blood and CSF out of the skull and maintain ICP. Once this compensatory mechanism is maxed out, there is an exponential increase in ICP.
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What is cerebral perfusion pressure defined as?
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CPP = MAP - ICP
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What is a normal ICP?
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10 mmHg
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What ICP is associated with poor outcomes?
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>20 mmHg
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What is the range of MAP during which autoregulation occurs?
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MAP of 50-150 mmHg will maintain constant cerebral BF
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What are 5 ways to enhance cerebral BF and perfusion?
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1. Reducing elevated ICP
2. Maintaining normal intravascular volume 3. Maintaing a normal MAP 4. Restore oxygenation/normo-capnia 5. Evacuate hematomas early |
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If there is asymmetry when testing for the GCS, what is important?
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Use the best motor response to calculate the score (most reliable predictor of outcome)
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Describe the E in GCS
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Eye opening:
4 - spontaneous 3 - to speech 2 - to pain 1 - none |
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Describe the V in GCS
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Verbal response:
5 - oriented 4 - confused convo 3 - inappropriate words 2 - incomprehensible sounds 1 - none |
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Describe the M in GCS
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Motor response:
6 - obeys commands 5 - localizes pain 4 - flexion w/d to pain 3 - abnormal flexion (decorticate) 2 - abnormal extension (decerebrate) 1 - none (flaccid) |
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A patient with cerebral contusions require what?
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repeat CT scans to evaluate for changes in injury pattern w/in 24 hours of initial scan -- up to 20% of pts show evolution of intracerebral hematoma or convalescent contusion w/ enough mass fx to require surgical evacuation
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Mental status changes in a drunk trauma patient are what until proven otherwise?
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Brain injury
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What is a minor brain injury?
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GCS of 15-13
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When do patients w/ a minor TBI require a CT scan?
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1. Clinically suspected open skull fracture
2. Any sign of basilar skull fracture 3. 2+ episodes of vomiting 4. Pt 65+ yo |
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What is a moderate TBI?
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GCS of 12-9
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What must be carefully avoided in moderate TBI patients?
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1. Hypoventilation
2. Decreased ability to protect airway 2/2 depressed MS AVOID NARCOTICS and HYPERCAPNIA |
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What is a severe TBI?
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GCS of 3-8
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What level of midline shift indicates the need for surgical intervention?
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A shift of >=5mm
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What is the danger in treating a seizure patient with muscle relaxants alone?
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Masked muscle contractions to not reflect the abnormal brain function -- can be devastating and MUST be treated with anti-seizure meds before NM blockade, if at all possible
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What is the role of hyperventilation in TBI patients?
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PCO2 should be maintained at low end of normal (35 mmHg - 45 mmHg)
Hypervent-->dec PaCO2 (25-30 mmHg)-->cerebral vasoconstriction-->dec ICP **However, prolonged periods of hypervent lead to ischemia-->devastating to already injured brain** Good to temporarily relieve ICP before taking patient to OR for definitive craniotomy-->use it in moderation and for as limited a period as possible! |
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Name 6 medical therapies for TBI.
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1. IVF to maintain MAP
2. Hyperventilation 3. Mannitol 4. Hypertonic saline 5. Barbiturates 6. Anticonvulsants |
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What is the role of anticonvulsants in medical therapy of TBI?
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Can inhibit brain recovery-->use only when absolutely necessary!
phenytoin is currently acute phase DOC |