Traumatic Brain Injury (TBI) Flashcards
Causes of TBI
Object striking head
-Head striking non moving object
-Acceleration/Deceleration of brain without external impact
-Foreign body penetrating brain
-Force from blast or explosion
Its what you think it is, anything causing trauma to brain
Most common cause of TBI
Falls
Motor vehicle accidents are number 2
Closed head trauma
Acceleration and rapid deceleration or collision with a blunt force causing dmg to brain tissue
-Your brain is rattling around in your skull
Open head trauma
Your head is opened, and the object that causes the trauma damages brain tissue and/or dura matter
Concussion
Mild TBI that can affect brain function
-Usually temp, but can lead to headaches and problems with concentration memory, balance and coordination
-Happens in sports
Contusion
Brain bruise as a result of the brain bouncing off the inside of the skull
-Can be coup or contrecoup sites
Diffuse axonal injury
-Shearing of brain’s long connecting nerve fibers (Axons) when the brain shifts and rotates within the bony skull from the primary injury
-Essentially grey matter rubs on the skull causing friction, tearing away from the white matter tearing those nerve fibers
Intracranial hemorrhage
Bleed in the skull
Epidural hemorrhage: Skull and dura matter
Subdural hemorrhage: Below dura matter
Subarachnoid hemorrhage: In subarachnoid space
Intraparenchymal hemorrhage: Brain bleed
Primary brain injury
Occurs at time of injury
-Directly as a result of force against the skull
-Shearing of tissue, tears, and bruising of brain tissue
-Local or diffuse
-Goal is to prevent secondary injury
Secondary Injury
-Comes after the initial injury
-Results from inadequate nutrients and oxygen to brain cells
-Hematoma formation (Epidural, subdural, Intraventricular, intracerebral)
-Cerebral edema (Swelling of brain tissue)
-Increased ICP
-Infection (Open head injury)
-Elevated temp (Increased metabolism and cerebral perfusion pressure)
Normal ICP
0-15 mmHg max upper limit is 15
Coup
Primary impact
Contrecoup
Brain slamming to opposite side after the primary impact
Basal skull fracture
-Occurs in the floor of the skull, areas around eyes, ears, nose or at the top of the neck near the spine
-Raccoon eyes
-Battle sign
-Caused by bleeding out of the skull,CSF can leak out of these areas too
Raccoon eyes
Bruising around the eyes indicating bleeding from the skull
Battle sign
Bruising of the mastoid process, (Behind the ear) indicative of bleed
Patho of TBI
TBI occurs
-Brain swelling or bleeding increasing intracranial volume
-Rigid cranium allows no room for expansion increasing ICP
-Increased ICP puts pressure on the blood vessels slowing flow to the brain
-Cerebral hypoxia and ischemia occur
-ICP continues to rise, brain may herniate
-Cerebral blood flow ceases
Intracranial pressure (ICP)
Pressure inside the skull from brain, tissue and CSF
Normal is 0-15
Cerebral spinal fluid (CSF)
FLuid that is in the brain, ventricles and spine
Cerebral perfusion pressure (CPP)
Pressure gradient that drives o2 delivery to cerebral tissue
-Normal is 60-80 mmHg
-Calculated by (CPP= MAP-ICP )
Mean arterial pressure (MAP)
Average pressure in a patients arteries in one cardiac cycle
MAP= (SBP+ 2(DBP))/3
Monro-Kellie doctrine
-3 parts to a cranial vault
-Blood
-Brain
-CSF
If there is an increase in one there is has to be a decrease in the others (Hopefully not the brain). And if there isnt a compensation with the blood or CSF the brain herniates
First sign of increasing ICP
Cushings triad
Cushings triad
-Increase in SYSTOLIC BP
-Decrease in pulse
-Decrease in respiration
Glasgow coma scale
-Determine level of consciousness, gauging severity of TBI, and can correlate with outcome of TBI
-Gauged on 3 categories
Eye opening
Verbal responses
Motor response
Min is 3
Max is 15
Glasgow coma scale: Totally fine
15
Glasgow coma scale: Comatose
8 and below
Glasgow coma scale: Totally unresponsive
3
Glasgow coma scale: Eye opening response
4 Spontaneously opens eyes
3 To speech
2 To pain
1. No response
Glasgow coma scale: Verbal response
5 Orientated times 3
4 Confused speech
3 Inappropriate words (Dont fit the context)
2 Incomprehensible sounds
1 No response
Glasgow coma scale: Motor response
6 Obeys commands
5 Moves to localized pain (Guarding and such)
4 Flexion withdrawal to from pain
3 Abnormal flexion (decorticate)
2 Abnormal extension (Decerebrate)
1 No response