TBI pathophysiology Flashcards
Primary brain damage - diffuse axonal injury
disruption and tearing of axons and small blood vessels from shear strain of angular acceleration
- results in neuronal death and petechial hemorrhages
Primary Brain Damage - Focal injury
- contusion, laceration, mass effect from hemorrhage and edema (hematoma)
Primary Brain damage - Coup-Contracoup
injury at point of impact and opposite point of impact
Secondary brain damage/secondary cell death: Hypoxic-Ischemic injury
results from systemic problems that compromise cerebral circulation
Secondary brain damage/secondary cell death: Swelling/Edema
can result in mass effect with increased intracranial pressures, brain herniation and death
Secondary brain damage/secondary cell death: Electrolyte imbalance
can lead to mass release of damaging neurotransmitters
What is a concussion
loss of consciousness, either temporary or permanent resulting from injury or blow to the head with impaired functioning of the brainstem reticular activating system
- can lead to Changes in HR, RR, BP
Levels of TBI - Mild
- LOC: 0-30 mins
- Alternation of Consciousness: brief, >24 hrs
- Post-traumatic amnesia: <1 day
- GCS: 13-15
- Imagining: Normal
Levels of TBI - Moderate
- LOC: >30 mins but <24 hr
- AOC: > 24 hrs
- PTA: > 1 day but < 7 days
- GCS: 9-12
- Imaging: normal or abnormal
Levels of TBI - Severe
- LOC: > 24 hrs
- AOC: > 24 hrs
- PTA: > 7 days
- GCS: <9
- imaging: normal or abnormal
What are the 6 recovery stages from diffuse axonal injury?
- coma
- unresponsive wakefulness syndrome/vegetative state
- mute responsiveness/minimally responsive
- confusional state
- emerging independence
- intellectual/social competence
coma
a state of unconsciousness in which there is neither arousal nor awareness
- eyes closed
- no sleep/wake cycle
unresponsive wakefulness syndrome/vegetative state
marked by the return of sleep/wake cycles and normalization of vegetative functions (respiration, digestion, BP)
- persistent vegetative state is determined if pt remains in state > 1 yr
mute responsiveness/minimally responsive
state in which pt is not vegetative and does show signs, even if intermittent, of fluctuating awareness
confusional state
mainly a disturbance of attention mechanisms; all cognitive operations are affected, pt is unable to form new memories, may demonstrate either hypo or hyperarousal
emerging independence
confusion is learning and some memory is possible; significant cognitive problems and limited insight remains, frequently uninhibited social behaviors
intellectual/social competence
-increasing independence although cognitive difficulties persists along with behaviors and social problems
11 things to examine post TBI
- increased intracranial pressure
- LOC/cognitive function
- CN function
- emotional dusregulation
- changes in behavior
- speech and communication
- sensory deficits
- motor function
- functional mobility skills, ADLs
- level of general reconditioning
- sympathetic storming
What is sympathetic storming
- result of hypothalamic stimulation of SNS with an increase in circulating corticoids and catecholamines
How to examine for sympathetic storming
- examine for alterations in LOC, increased posturing, dystonia, hypertension, hyperthermia, tachycardia, tachypnea, diaphoresis, and agitation
- pt generally exhibits minimal altertness, minimal awareness and reflective motor response to stimulation
