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51 Cards in this Set
- Front
- Back
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Define Cerebral perfusion pressure CPP
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the difference between inflow and outflow (of cerebral blood perfusion) the driving pressure for cerebral blood flow
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Define Intracranial pressure (ICP)
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the pressure of CSF in the subarachnoid space. Determined by volume of intracranial compartments. Normal is <15 mmHG
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Define cerebral blood flow
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flow of blood in the cerebrum autoregulated by pCO2, BP, pH of blood and O2 levels
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Define contra-coup injury
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contusions of the brain on the side opposite the site of a blunt trauma
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Define concussion
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any alteration of cerebral fuction caused by a force to head resulting in: brief LOC, light-headed, vertigo, HA, N/V, photophobia, cognitive dysfunction, memory loss, tinnitus, blurred vision
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Define Post-concussive syndrome
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pt's continue to have complaints such as HA, dizziness, inability to concentrate, memory problems
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Discuss the epidemiology of head injury in terms of age, sex; those at greatest risk of brain damaage because of underlying factors and most common etiologies of death
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age: males 15-24 risk: ETOH, old, children Etiology: severe TBI mortality 40% in 48 hrs. Primary mech is cellular injury and death from force of injury. 2nd from local tissue ischemia
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What anatomical structures are in the scalp
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5 layers, (skin, subQ, galea, areolar, pericranium) rich blood supply
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What anatomical structures make up the skull
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8 major bones (
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What are the anatomical structures of the brain
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cerebral hemispheres: frontal, temporal, parietal, ocipital. Cerebellum and brainstem
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What are the outer layers of the brain
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Dura mater (outer most and adheres to skull) arachnoid (adheres loosely to pia mater creating subarachnoid space) Pia mater (closely associated with gray matter of brain, inner most layer)
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How much and where is CSF fluid is produced daily and surround structures
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500 mL produced daily in choroid plexus; 150 mL surround brain and spinal cord
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What labs may be important to order in evaluating TBI
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ETOH/drug screen, CSF pressure and panal (gluc., protein culture, etc.)
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What imaging should be used to evaluate head injury
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head CT
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Describe the relationship of ICP and auto regulation of cerebral perfusion. Identify what happens when ICP is out of its normal range
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when out of normal range, autoregulation is lost and CBF follows a linear passive-pressure relationship to the cerebral perfusion pressure
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HEAD INJURY
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HEAD INJURY
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List 3 factors that can increae TBI mortality
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1. hypotension 2. hypoxemia 3. Anemia
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Identify the 1st evaluation and managment priorities for TBI that should be addressed before neurological and mental staus exams can be evaluated
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ABC's! A: aggressive management RSI if indicated B: once airway patent, bag, vent, breath etc. C: aggressive fluid resuscitaion to prevent hypotension to keep MAP at 90.
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What is evaluated in the neruological and mental status for TBI
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AVPU: Altert, responds to Verbal stimuli, responds to Painful stimuli, Unresponsive. Use Glascow Coma Scale
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What does a single fixed and dialated pupil indicate
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ipsilateral intracranial hematoma with uncal herniation that requires immediate surgical decompression
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What do bilateral fixed and dialated pupils suggest
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increased ICP with poor brain perfusion, bilateral uncal herniation, drug effect or severe hypoxia
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What do bilateral pinpoint pupils suggest
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opiate or pontine (relating to the pons) lesion
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Identify the history components that need to be addressed regarding the head injury patient
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If possible, history is used with GCS to identify severity of TBI
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What ifomation needs to included in the history
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LOC? Amnesia, change in mental status, persistent or transient focal neurological deficit, vomiting, HA, coagulopathy, drug or ETOH consumption, previous neurosurgery, epilepsy
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A GCS score < 9 indicates what
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severe TBI: mortality up to 40% but less than 10% make even moderate recovery
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A GCS score 9-13 indicates what
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moderate TBI: mortality < 20%, long term disability up to 50%
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A GCS score 14-15 indicates whate
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mild TBI with subdivided categories of mild medium and high risks
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What are the low risks indications for a mild TBI
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GSC score 15, no LOC, amnesia, vomiting or HA.
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What are the medium risks indications for a medium TBI
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GCS of 15 with 1 of: LOC, amnesia, vomiting or HA. CT should be obtained
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What are the high risk indications for a high TBI
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GCS 14-15 with skull fx and/or neuro deficits. Should include those with coagulopathies, drug or ETOH consumption, previous neurosurgery, epilepsy or >60 regardless of clinical presentation
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Discuss initial steps that should be initiated in treatment of increased ICP.
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elevate head bed to 30*, adequate volume resuscitation to MAP of 90 mmHg, or a 30% reduction in MAP if hypertensive, and maintenance of adequate arterial oxygenation. After these steps mannitol should be used
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Explain the role of mannitol in increased ICP setting.
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best osmotic agent reducing ICP. beneficial effect on the ICP, CBF, CPP, and brain metabolism. Additionally, is known to scavenge free radicals, improves blood’s oxygen-carrying capacity, reduces ICP within 30 minutes and lasts 6-8 hours
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Identify the signs/symptoms of a basilar skull fracture
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CSF otorrhea or rhinorrhea, mastoid ecchymosis (Battle´s sign), periorbital ecchymoses (raccoon eyes), hemotympanum, vertigo, decreased hearing or deafness and seventh nerve palsy.
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Describe a simple test for fluid to determine if CSF is present in rhinorrhea or otorrhea
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Use paper towel - if + will leave ring appearance. Also, you can use glucometer if >30, probable CSF.
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Identify the cause of brain herniation and the most common site for it to occur.
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Cause: expanding lesion in temporal lobe or lateral middle fossa causing brain to be pushed out of place. Site: uncal; occurs when uncus of temporal lobe is displaced inferiorly through the medial edge of tentorium.
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Explain the ocular change that can be found with unal type of herniation
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compression of the 3r cranial nerve (oculomotor), causing ipsilateral fixed and dilated pupil. Compression on pyramidal tract leads to contralateral motor paralysis. In some cases the papillary changes are contralateral or motor changes are ipsilateral
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Discuss cerebral contusions
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one of most frequent types of TBI. most commonly occur in subfrontal cortex, the frontal and temporal lobes, and occasionally occipital lobes. often associated with subarachnoid hemorrhage. may occur at site of blunt trauma or contrecoup injury
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Discuss intracerebral hemorrhages
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can occur days after blunt trauma, often site of resolving contusions. more common with patients with coagulopathy, old. CT scans in immediate postinjury phase often normal
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Describe the etiology and presenting and symptoms of subarachoid hemorrhage (SAH)
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disruption of subarachnoid vessels and presents with blood in the CSF. Sx: mild to severe TBI. Those with isolated tSAH often present with HA, photophobia and mild meningeal signs
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Explain the role of CT scan in determining outcome and management of subarachnoid hemorrhage
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can be missed on early CT scans. scans done 6-8 hours after injury are more sensitive. Careful follow up instructions, referral for reexamination by physician, and discharge in the care of a competent adult are necessary, even with a normal CT scan
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Describe the etiology for epidural hematoma
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blood collecting in space between skull and dura mater. Most from blunt trauma to temporal or temporoparietal area with skull fracture and middle meningeal arterial disruption. Almost all epidural hematomas are associated with skull fractures
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Describe the classic history of epideral hematoma
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lucent period following immediate LOC after significant blunt trauma. Pt awakens and has lucent period prior to again falling unconscious
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Discuss imaging used to diagnose epidural hematoma
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CT scan and physical findings. On CT scans, epidural hematomas appear biconvex (football shaped), typically in the temporal region.
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Describe the etiology and mechanism for subdural hematoma (SDH)
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sudden acceleration- deceleration of brain parenchyma with subsequent tearing of the bridging veins
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Discuss who is more susceptible for subdural hematoma's and why
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Brains with extensive atrophy, such as the elderly and alcoholics, are more susceptible to subdural hematomas Children under the age of two
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Define diffuse axonal injury and its prognosis
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disruption of axonal fibers in the white matter and brainstem. Shearing forces on the neurons generated by sudden deceleration cause DAI. Classically, DAI is seen after blunt trauma, such as from MVA
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Identify the unfortunate cause of axonal injury seen in infants
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The “shaken baby syndrome” is a well-described tragic cause.
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List symptoms of concussion
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1+: brief LOC; light-headed; vertigo; HA; N/V; photophobia; cognitive and memory dysfunction; tinnitus; blurred vision; diff concentrating, amnesia; fatigue; personality change; or balance disturbance
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Identify the risk factors for infection due to a TBI, and when antibiotics should be started immediately
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Skull fractures and CSF leaks should be Tx with ABX. Others at risk: CNS infections, intubated pt's on neuromuscular blockades
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What types of brain injury would be sustained by a gunshot wound (GSW)
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As bullet passes thru the brain it creates a cavity 3-4 X's greater than its diameter. Direct penetration of bullet thru the brain transfers kinetic energy causing majority of destruction
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What types of brain injury would be sustained by a stab wound
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Stab wounds have very low energy and impart only direct damage to the area contacted by the penetrating object
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