TBI Flashcards
What are the levels of injury on the glascow coma scale?
- Mild injury = 13-15 pts
- Mod injury= 9-12 pts
- Severe = less than 9
What factor influences outcome?
Pre morbid state (decreased outcomes associated with previoius injury)
What are the types of of Primary injury?
- Local
- Coup-countercoup
- Polar damage
- Diffuse axonal injury
What are the types of local injury?
- Laceration
- Clot
- Contusion
What is coup-countercoup?
Blow to the skull on one side that causes brain to shift and be damaged on the opposite side:
- Skull pushes brain at same time as it accelerates
- on the opposited side there is momentary vacuum
- When skull stops accelerating vacuum collapses and brain hits skull
What is polar damage?
Result of an accel/decel injury and most commonly hits the frontal and temporal poles. Ocassionally occipital
What is damamged in DAI? and what are the levels of severity?
- Widely scattered shearing damage to axons
- Severity:
- Mild: little defecit
- Mod: wider areal of subcortical matter
- Severe: extends down and in to midbrain and brainstem (coma with posturing and autonomic dysfuntion
What are types of secondary injury?
- Hypoxemic Ischemic Injury-Brain tissue shifted as a result of swelling
- Intractranial hematoma- forms post injury due to cont. bleeding
- Increased ICP (normal <10 mmHg)
- Autodestructive Cellular phenomena (Cell suicide)
What is arterial hypoxemia?
A form of HII that results in much wider damage from anything shutting off O2 in the brain (MI, airway obstruction, arrythmia, PE)
What are the 2 scenarios for intracranial hematoma?
- “Talk and Die”- pt has as period of lucidity then loses consciousness and ultimately dies (due to space occupying lesion)
- Person in coma and has no lucid period-bleeding can go undetected which results in death
what are the 3 types of brain herniations?
Uncal, Central, Tonsillar
Characteristics of Uncal herniation
- Location: Tentorial notch, midbrain
- Cause: mass lesion in temporal lobe or middle fossa
- Structures involved: Hippocampal gyrus and uncus, occulomotor nerve, cerebral peduncle, midbrain ascending reticular activating system, PCA
- Clinical effects: Paresis of nerve 3, hemiparesis, coma, homonymous hemianopsia
Characteristics of Central herniations
- Location: same as uncal
- Cause: mass lesion in frontal, paretiel, or occipital lobe; progression of uncal
- Structures involved: midbrain, pons (causes decerebate rigidity); ascend. retic. activat. syst (coma)
Characterstics of Tonsillar:
- Location: Foramen magnum, medulla
- Cause: mass lesion in posterior fossa, Progression of central herniation
- Structures involved: Cerebellar tonsils (neck pain and stiffnes), Indirect activation pathways (flaccidity), ascend retic. activat. syst (coma), Vasomotor centers (alters pulse, BP, respiration)
What is ACP? How is it treated?
Increase in excitatory neurotransmitters (glutamate) due to activation of calcium dependant enzymes that destroy more tissue. Treat: cooling; hyperbaric O2, free radical scavengers
How is a TBI medically managed?
- Monitor TBI
- check values (>25 mmHg usually requires intervention; <20 for 24 hrs discont. monitoring)
- Prevent increasing ICP (avoid dependent posns)
- Meds (check interaction with therapy)
- can increase spasticity and decrease patient willingness to particpate
What are impairments associated with TBI?
- Cognitive Deficits
- neuromusclar deficits
- Visual deficits
- Perceptual Deficits
- Swallowing deficits
- Behavioral Disinhibition
- Commuincation Deficits
- Cognitive impairments
- Behavioral Impairments
What constitutes a coma?
8 or lower on GCS. (if can open eyes and has sleep wake cycles, but cannot obey commands = vegetative)
What is post traumatic amnesia?
Time between injury and when patient begins to remember ongoing events
What are behavioral deficits?
Sexual disinhibition, emotional disinhibition, aggressive disinhibition, apathy, depression, low tolerances for frustration
Remember that behavior problems are a result of damage, not personal
What are indirect impairments?
- contractures (hand, wrist,PF)
- decreased endurance
- DVTs
- Mobility deficits
- Pneumonia
- Heterotopic ossification (development of bone tissue within soft tissue of unknow cause), confirmed by x-ray; typically in elbow or hip flexors; avoid agressive stretching)
What are major areas requiring intervention?
- Increase level of consciousness
- Avoid seconday impairments
- Posturing and tone issues
- Maintaining joint integrity
- Increasing intolerance of positions and activities
- Family education
What is the purpose of sensory stimulation?
To increase the LOC through multi-system sensory input in the RAS
What are purposes of positioning?
- Decrease posturing and thereby possibly reduce ICP
- Decrease tone
- Reduce risk of contractures
- Prevent skin breakdown