Neuro Flashcards
What does a CT show?
shows different layers and tissue density
What is the main job of the nurse in relation to CT scans?
Check for allergies to iodine or shellfish
Contrast can worsen these and cause an allergic reaction
When might you use sedation for a CT scan?
On a combative patient
What does an MRI show?
chemical changes in the cell
What can a patient not have to get an MRI?
- pacer
- aneurysm clips
- valves
- patches
- piercings
- intrauterine devices
what is a lumber puncture?
removal of CSF for diagnostics and pressure measurement
Where do they insert the needle for an LP?
inserted into the 3-5th lumbar vertebrae into the subarachnoid space
When is an LP contraindicated?
- With increased ICP because it is not as effective as an EVD
- depends on the cause of increased ICP, LP can cause brain herniation
- positioning is also contraindicated for those with increased ICP
what is the most common illness in need of a LP?
looking for infection, most often meningitis
What are some complications of LP?
- Headaches
- Infection
- hematoma
Why may a headache result from an LP?
frontal or occipital headaches may occur due to a leak of CSF
Why is a blood patch used?
If the patient has a headache after an LP, they draw blood from the patient and inject into the epidural space in order to clot/close the area with the leak
What is the brain requirement for oxygen?
constant supply of oxygen
What amount of CO does the brain require?
15-20% of cardiac output
How much glucose does the brain require?
the brain uses 15% of the body glucose, it has a high metabolic demand.
fill in the blank:
_____ ____ is required to meet the brains nutritional requirements
blood flow
where is glucose stored?
in the brain
what is CPP?
cerebral perfusion pressure: the amount of perfusion to the brain
what percent of the body energy demands does the brain require?
20%
what is included in a neuromuscular assessment? (5)
- level of consciousness
- motor response/strength
- pupillary response
- reflexes
- VS
why are LP’s contraindicated with increased ICP?
if you remove the cerebrospinal fluid it creates a pressure gradient that may cause downward herniation
what is the first sign of neuromuscular changes in the elderly?
Changes in LOC
What do blown pupils look like?
large and nonreactive
What do blown pupils indicate?
brain death
In eye opening what is the scale for the GCS?
4-opens eyes spontaneously
3-opens eyes to speech
2-opens eyes to pain
1-none
in verbal response, what is the scale for GCS?
5-orientated 4-confused 3-inappropriate 2-incomprehensible 1-none
in motor response what is the scale for GCS?
6-obeys commands 5-localizes to pain 4-withdraws to pain 3-flexion to pain 2-extension to pain 1-none
What is the GCS requiring intubation?
less than 8- intubate
what GCS indicates mild disability?
GCS of 13-15
what GCS indicates moderate disability? (4)
- GCS of 9-12
- LOC greater than 30 minutes
- Physical or cognitive impairments which may or may not resolve
- benefits from rehab
What GCS indicates severe disability? (4)
- GCS of 3-8
- unconscious state
- no meaningful response
- no voluntary activities
what GCS indicates vegetative state? (4)
- GCS less than 3
- sleep/ wake cycles
- arousal with no interaction with environment
- no localized response to pain
what is used to monitor interaction with environment?
continuous EEG
persistent vegetative state
- EEG
- long term vegetative state lasting longer than a month
- long term coma
is a vegetative state indicative of brain death?
no!!! it is a lack of concsiousness
What indicates brain death?
no brain function
no cerebral blood flow
what is a potential cause of brain death?
herniation
what do you assess when looking at pupils? (4)
- size
- shape
- reactivity to light
- comparison of one pupil to the other
What pupillary sign may indicate increased intracranial pressure?
sluggish pupils can indicate increased ICP
maybe caused by compression of the third cranial nerve, cerebral edema, and herniation
What are pupillary signs of brain death?
nonreactive and fixed pupils indicate brain death
big and blown with a loss of light reflex
what is anisocoria?
different-sized pupils
what is the doll’s eyes assessment?
moving the head back and forth to see how the eyes react
what is a normal response to the doll’s eyes assessment?
deviation of the eyes to the opposite side of head-turning
indicates brain function
what is an abnormal response to the doll’s eyes assessment?
oculocephalic reflexes are absent, no eye movement in response to head movement; eyes stay straight
what is the corneal reflex test?
using a wisp of cotton and touching the cornea lightly
the normal response to the corneal reflex test?
patient should blink
abnormal response to the corneal reflex test?
no response, no presence of the reflex
what does it indicate when the patient does not blink with the corneal reflex test?
brain stem dysfunction or brain death
what is the cold caloric test?
a small amount of cold water is delivered into the inner ear canal
what does the cold caloric test stimulate?
the inner ear nerves- vestibulocochlear
what does the cold caloric test cause?
rapid nystagmus
what is a normal response from the cold caloric test?
both eyes move away and then towards the cold water
what is an abnormal response to the cold caloric test?
no response
what is a response to the cold caloric seen in patients in a coma without brainstem death?
eyes tonically deviate toward cold water
what is decerebrate posturing?
arms and legs flexed, the patient is very stiff
what is decorticate posturing?
hands to the chest
what is decorticate posturing a sign of?
overstimulation
what is a decerebrate posturing a sign of?
brain stem damage
what is the most important indicator of brain function?
LOC
fill in the blank:
_______ ___ is not a disorder but a resort of pathology.
altered LOC
symptoms of a coma
unconscious
unresponsive
inability to arouse
symptoms of persistent vegetative state
no cognitive function but has sleep-wake cycles
the patient is not brain dead.
what is locked-in syndrome?
the patient is unable to move or respond except for eye movements due to a lesion affecting the pons
the patient can feel everything but cannot move
what is the formula for CPP?
CPP=MAP-ICP
what is a herniation of the brain?
brain tissues shifting through the dura and sinking into the skull base,
the brain moves into the brainstem and is a very common cause of brain death
what is auto regulation?
the brains ability to change the diameter of blood vessels to maintain cerebral blood flow
what does decreased c02 cause?
vasoconstriction
what does increased c02 cause?
vasodilation
what does increased fluid cause in the brain?
increased ICP
Pts with high ICP become ___________
hypercapnic
what are some main s/s of Increased ICP? (10)
- HA
- N/V
- Decreasing LOC
- unilateral motor loss
- change in respiratory pattern
- change in pulse pressure
- loss of temp control
- restlessness
- seizures
- posturing
what causes a change in pupil size/reaction?
3rd cranial nerve compression
what is unilateral motor loss?
loss of motor function on one side of the body
what is the primary concern with seizures?
the brain is not getting enough oxygen
How does the body compensate for increased ICP in relation to HR?
tachycardia to bradycardia
what is cushing’s triad?
- Increased systolic with widened pulse pressure
- bradycardia
- decreased respiratory rate or change in pattern
Late s/s of increased ICP?
- bradycardia
- apnea
- cushing’s triad
- decorticate/decerebrate posturing
- alteration in pupil size/reactivity
- seizure
- papilliedema
what is papilliedema?
increased pressure in the brain causes part of the optic nerve inside the eye to swell
what are symptoms of papilliedema?
vision changes, HA, Vomiting
what causes cushing’s triad?
increase in sympathetic outflow to the heart as an attempt to increase arterial blood pressure and widening pulse pressure
when is cushing’s triad seen?
seen in terminal stages of head injury, this is a late sign
how do you monitor for declining neuromuscular function? (7)
- neuro checks
- LOC
- GCS
- pupils
- speech assessment
- motor function
- VS
what is an indication for Q15 neuromuscular checks
with Increased ICP
True or false:
increased ICP is always distributed evenly throughout the brain
FALSEEEEEEEEE!!!!
compression and swelling may be unequal.
true or false:
EVD’s are inserted on the same side of the brain as the affected area
FALSEEE BRO
EVDS are always put on the opposite side of the affected area.
what is Pbt02?
brain oxygenation
what factors represent how much to drive BP?
- ICP
- CPP
- Pbt02
what is a normal Pbt02 for normal brain tissue?
> 20
What level of oxygenation in the brain indicates hypoxia
pbt02 of 10-20mmHg
what level of oxygenation in the brain indicates ischemia?
<10mmHg, this is irreversible
What is CPP?
Cerebral perfusion pressure, amount of perfusion in the brain
what is CPP closely linked to ?
ICP
What is a normal CPP?
70-100
what does a CPP of less than 50 represent?
permanent neuro damage
what is a normal Pbt02?
20-40mmHg
true or false
CPP and CBF are the same thing.
FALSE
CPP represents perfusion, while CBF represents blood flow
true or false:
In brain death, CBF is not noted.
TRUE
CBF is not noted due to the ischemia of the brain
with increased ICP we want to ______ the volume of ___.
reduce
CSF
what are 4 ways to reduce the volume of CSF?
- EVD
- Ventriculostomy
- VP shunt
- diuretics
what is a normal ICP
5-15
what do you want to avoid with increased ICP?
- suctioning, turning, bathing
- head flexion and extension- off of the midline
- valsalvas maneuver
what is a ventriculostomy?
surgical placement of tube in the ventricle of the brain
why is a ventriculostomy used?
to monitor ICP and relieve pressure through the drainage of CSF.
nursing responsibilities in relation to EVD?
- level at the tragus
- correct pressure set
- tubing/clamps/stopcocks open
- monitor drainage
- do not move patient
- check dsg and insertion site
True or false
nurses are able to do dsg changes on an EVD
FALSE
only the doctor can do dsg changes since it is at such high risk for infection
what is an LP?
lumbar puncture
what is a lumbar drain?
a line hooked up to an EVD used to relieve high pressure of CSF
what is the goal of a lumbar drain?
drain and test CSF
how can we manipulate CPP?
pressors
CPP and ICP are _______
inverse
ways to drive CPP? (3)
- pressors
- fluids
- CSF drain
ways to minimize ICP?
- sedation
- osmotic agents
- ventriculostomy
- position
- paralytic agents
what are some examples of sedation?
opiates
barbs
propofol
What is Pbt02?
brain tissue oxygen
ways to increase brain 02?
draining CSF
increasing MAP/ICP
Decreasing temp
Barbituates
what are some commonly used vasopressors?
- dopamine
- low dose levo
- neosynephrine
- vasopressin
what is the danger of low CO?
no perfusion
what is the point of early gut functions?
the brain needs glucose to funciton
