TBI Flashcards
Traumatic Brain Injury
mechanisms of injury includes penetrating or blunt trauma to the head
penetrating trauma: can be result of penetration from foreign object (e.g. bullet) that causes direct damage to cerebral tissue
blunt trauma: can be result of deceleration, acceleration, or rotational forces
*with all head injuries, you must assume cervical spine injury until it has been ruled out
Acceleration and Deceleration Injuries
acceleration injuries: occur when brain has been hit by something and brain moves forward to the point of impact (initial injury)
deceleration injuries: cause the brain to crash against the skull after it has hit something (brain hitting back of skull)
ex) whiplash
Primary Injury
occurs at the moment of impact as a result of mechanical forces to the head
includes: contusion laceration shearing hemorrhage
Secondary Injury
occurs when the biochemical and cellular response to the initial trauma that can exacerbate the primary injury and cause loss of brain tissue not originally damaged
includes: ischemia hypercapnia hypotension cerebral edema sustained HTN
Contusion
bruising of brain r/t accel/decel aka coup/contrecoup injuries
contusions can progress over 3-5 days following the injury
small contusion tx: neuro exams and ICP monitoring
large contusion tx: surgical intervention to prevented increased edema and ICP
Concussion
a brain injury accompanied by a brief loss of neurologic function, esp loss of consciousness (seconds to an hour)
neurologic dysfunction includes:
- confusion
- disorientation
- post-traumatic amnesia
pt w/ loss of consciousness of 5 or more minutes need to be observed for a 24 hour period
Concussion: Clinical Manifestations
- HA
- dizziness
- nausea
- irritability
- inability to concentrate
- impaired memory and fatigue
Skull Fracture Classification
open: dura is torn
* risk of meningitis d/t torn meninges
closed: dura is not torn
Skull Fracture: Clinical Manifestation
CSF otorrhea or rhinorrhea
Battle’s sign
Raccoon eyes
Types of Skull Fractures
simple: a break in a cranial bone without damage to the skin
depressed: a break in a cranial bone w/ depression of the bone in toward the brain
linear: a break in a cranial bone resembling a thin line, without splintering
compound: a break in or loss of skin and splintering of the bone. along w/ the fracture, brain injury like subdural hematoma can occur
* all can be open or closed
Hematomas: Types
Epidural and Subdural: occur outside the brain tissue
Intracerebral: bleeding into brain tissue itself (directly damage neural tissue and can produce further injury as result of pressure and displacement of intracranial contents)
Epidural Hematomas
collection of blood between the inner table of the skull and the outermost layer of the dura
most often associated w/ skull fractures
d/t arterial bleeds
Epidural Hematomas: Clinical Manifestation
- steadily progressive
- rapidly advancing coma (increased ICP)
- unconscious > lucid > unconscious (b/c of way head is bleeding
- seizures common
- can look like stroke sx
- less fatal b/c sx occur faster therefore it’s more noticeable
Subdural Hematoma
collection of blood between the dura and underlying arachnoid membrane
most often related to rupture in the bridging veins
caused by: acel/decel and rotational forces
d/t venous bleeds
commonly seen in: alcoholics (d/t frequent falls) and elderly (aging shrinks brain and stretches vessels w/ falls)
Subdural Hematomas: Clinical Manifestation
- slow to develop sx (don’t show until the end when it’s almost too late which is why mortality rate is high)
- can occur w/ or w/o trauma
- decreased LOC
- ipsilateral pupil dilated
- seizures are less common
Intracerebral Hematoma
bleeding occurs w/in cerebral tissue
caused by:
- depressed skull fractures
- penetrating injuries (bullet, knife)
- sudden accel/decel motion
Missile Injuries
caused by objects that penetrate the skull which causes focal damage but little accel/decel or rotational injuries
depressed injuries: caused by fractures of the skull w/ penetration of bone into the cerebral tissue
penetrating injuries: caused by a missile that enters the cranial cavity but does not exit
perforating injuries: caused by missile injuries that enter and then exit the brain
risk of infection and cerebral abscess d/t fragments embedded w/in the brain
Head Injury and C-Spine Injury
all cases of head injury, assume c-spine injury also until it’s ruled out
- stabilize pt on spine board using log roll maneuver
- neck should be immobilized in well fitted c-collar and padded head immobilization device
- avoid tight c-collar (any pressure on the external jugular veins will increase ICP)
Neurological Exam of TBI Pts
- glasgow coma scale
- brainstem exam
- motor exam
- sensory exam
- peripheral reflex exam
*many pt’s w/ TBI have significant alterations of consciousness and/or pharmaceuticals present that limit the scope of the exam
**if muscle relaxants have been administered, the only aspect of the neuro exam that may be evaluated is the pupillary exam
Glasgow Coma Scale
screening exam that involves:
- eye opening
- verbal response
- motor response
highest score = 15
score interpretation:
<9 = severe head injury
9-12 = moderate head injury
13-15 = minor head injury
coma = 3
Response to Painful Stimuli
flexor posturing/decordicate posturing
extensor posturing/decerebrate posturing
flaccid (indicates brain stem herniation)
Brainstem Exam
pupillary exam
ocular movement
corneal reflex
gag reflex
may not get corneal reflex esp in those who wear contacts b/c putting in contacts dulls corneal reflex so we don’t totally rely on this
