Central Nervous System TRAUMA Flashcards
What are primary head injuries?
initial damage, direct injuries
result of a force applied to the head
tissue and vascular damage
What are secondary head injuries?
result of HYPOXIA and decreased perfusion from initial damage/ primary injury
What does increased intracerebral pressure result in?? (in terms of blood flow)
decreased blood flow
What does decreased CO2 levels cause? (chain reaction….)
HYPOventilation > cerebral vasoconstriction > cerebral ischemia (hypoxia)
What does increased CO2 levels cause?? (chain reaction)
HYPERventilation > vasodilation & edema (HYPOXIA)
What is the normal intracranial pressure inside the cranium??
5-15mmHg (15 is upper normal limit)
What are the TWO things we need for our brain to survive ?????
GLUCOSE AND O2
What does CPP stand for?? and what does it mean?
cerebral perfusion pressure- the pressure needed to maintain blood flow to the BRAIN!!!!!
What does our CCP need to be at in order to survive!?
70-80mmHg!!!!
What does MAP stand for…. what does it mean?
Mean arterial pressure, the product of cardiac output and total peripheral vascular resistance
should be 70-100mmHg
What does our MAP need to be at?
70-100mmHg
What is the equation for Cerebral Perfusion Pressure??
CPP= MAP (mean arterial pressure) - ICP (intracranial pressure)
What happens the ICP= MAP?
blood flow stops!!!!
What are the early signs of ICP?
shift CSF to the spinal cavity to compensate
and decreasing cerebral blood flow
severe headache
vomiting- projectile
papilledema- swelling of the optic disc and ICP
seizures
**signs increased in severity until ICP is controlled
Because of the compensation our body…. ICP is significantly ______ before the signs become apparent!!!
ELEVATED
If ICP continues to build up what reflex takes over as the vasomotor center of the brain?
Cushing reflex’s
What is cushing’s reflex? What is it’s purpose?
decreasing pulse
increasing systolic pressure with widening pulse pressure
irregular resps
- attempting to increase the blood supply to the brain!!
Barorecpetors in the ____ arteries respond to the increase in BP by ______ the heart rate!
carotid
slowing
Chemoreceptors respond to ____ CO2 levels from accelerated systemic circulation by ______ the resp rate !!
LOW
slowwwwwing
Is death inevitable if the pressure (ICP) is not released?? True or false?
TRUE
Three symptoms of CUSHING’S response?
HTN (widening pulse pressures)
BRADYCARDIA
IRREGULAR RESPS
What is cerebral herniation syndrome?
brain swelling eventually forces tissues downward through the foramen magnum
obstruction of blood flow
pressure on the brain stem- vital centers that causes death
What are the s/s of cereberal herination syndrome?
decreased LOC, coma
dilation of pupil on same side
paralysis on the opposite of the body
deceberate posturing (extension)
increased BP
bradycardia
What is tx for cerebral herniation syndrome??
hyperventilation to reduce swelling 1:3 seconds!!
What does hyperventilation do for the pt with cerebral herination syndrome?
induce vasoconstriction and decreasing blood to brain and swelling!!!
What is something we need to remember with scalp wounds?
they bleed a LOT.
What are the 5 diff types of brain injuries?
- concussion
- cereberal contusion
- diffuse axonal injury
- anoxic brain injuries
- closed head injuries (contrecoup injuries)
What is component of assessment is important when dealing with concussions?
history of trauma- mild blows to the head cause excessive movement of the brain!!
What is happening to the brain during a concussion?
getting hit in the head
creates a brief disruption of neural function,
resulting in a period of unconsciousness or confusion, then return to normal, short term memory loss (amnesia)
What are s/s of concussions?
headache, dizziness, tinnitus, nausea
What is a cerebral contusion?
bruised brain tissue with ruptured small blood vessels (usually from a blow to the head)
brain swelling may be rapid and severe
S/S of cerebral contusion??
prolonged unconsciousness
altered LOC
personality changes
profound changes
persistant amnesia
abnormal behaviour
focal neurological signs
What is a basilar fractures??
’s that occur at the base of the skull
What are the s/s of basilar #’s?
often accompanied by leaking of CSF through the nose and ears (rhinorrhea and otorrhea)
dark discolouration around the eyes and behind the ears
When do basilar #’s often occur?
when the forehead hits a car windshield with considerable the ears
What is a depressed skull #?
displacement of a piece of bone below the level of the skull
compresses the brain tissue
blood supply to that area = imparied
ICP is high
What is a diffuse axonal injury??
the most common head injury
severe blunt head trauma
injury to the brain, stretching, shearing, tearing of nerve fibers, from brain moving back and forth
subarachnoid bleeding with irritation to the surrounding tissues
What s/s of diffuse axonal injury?
seizure activity, coma, vomiting, herination syndrome is possible, permanent vegetative state
What is an anoxic brain injury?
lack of oxygen to the cells from cardiac arrest, airway obstruction, drowning
What is the time of anoxia it takes for it be irreversible??
4-6 mins of anoxia!!!!
restoring blood pressure and oxygen will NOT restore perfusion
What is contrecoup injury?
rebound of the skull causes the brain to impact the opposite side of the skull
What is a spinal cord injury?
fracture or dislocation of vertebrae which stretched, compresses or tears the spinal cord
