CVA - 1b Dx, Clinical Presentation, Med Management Flashcards
why is a-fib a risk factor for strokes
inc risk of forming clots -> can dislodge and travel to brain -> ischemic stroke d/t embolic stroke
what are 5 predictors of strokes and what do they all have in common
afib
HTN
hyperlipidemia
DM
AVN
all vascular in nature
TIA vs CVA
TIA - temporary sx that will resolve w/i 24hrs
- “mini stroke”
- can be treated w dec likelihood of deficits
according to literature on health inequities, what has led to best outcomes s/p CVA
go somewhere w specialized stroke unit
- not always available
what are the 4 main characteristics of ischemic strokes that are different from hemorrhagic
more common
treated w tPa (clot busters)
clot - thrombus or embolus
dec O2 perfusion
describe the use of tPa in ischemic strokes
clot busters - break down the blood clot to help restore blood flow
- get w/i certain window of opportunity from onset of sx for optimal efficacy (w/i few hours)
what role does dec O2 perfusion play in ischemic strokes
can be secondary to or the cause of the stroke
what are 6 reasons for dec O2 perfusion that can lead to an ischemic stroke
low BP
pulm cause
MI
blood loss (abdominal surgery, trauma)
sickle cell anemia
vasospasms
what are vasospasms and when are they seen
blood vessels are spasming and constricting -> dec blood flow
- d/t raynauds, SAH
how can ischemic strokes transition to hemorrhagic strokes over time
similar path of swelling and edema
- > transition to hemorrhagic
what are the 2 types of hemorrhagic strokes
intracranial hemorrhage (ICH)
subarachnoid hemorrhage (SAH)
what are the 5 main characteristics of hemorrhagic strokes that are different from ischemic strokes
inc mortality rate
inc risk of midline shift
inc edema
inc risk of hydrocephalus
inc risk for brainstem herniation
why is there an inc mortality rate associated w hemorrhagic strokes
bleeding into brain -> inc fluid in brain -> inc fluid needs space -> pushes brain matter over -> midline shift d/t edema
why is there an inc risk of hydrocephalus associated w hemorrhagic strokes
inc fluid in ventricles bc of blood -> putting a lot of pressure on brain
what specific type of hemorrhagic stroke is hydrocephalus commonly seen in
SAH
how is hydrocephalus commonly treated
w EVD (extra-ventricular drain)
- tube placed in ventricle to drain fluid and dec pressure
why is back pain associated w hydrocephalus secondary to hemorrhagic strokes
blood more dense than CSF, then travels down SC and hangs out in base of SB
- blood is irritable to SC and toxic to neural tissue -> irritates nerves -> LBP and leg pain
how is LBP and leg pain d/t hydrocephalus secondary to hemorrhagic strokes managed
transient - give them gabapentin (meds for nerve pain)
- blood eventually get resorbed
what is the clinical significance of working w someone who is being treated for hydrocephalus
pay attention to ICP (<125)
- drain has to be clamped before movement, then not getting CSF movement out and can see issues w ICP
what do clinical features of a stroke depend on (2)
location and severity of stroke
why is your impairment exam of someone w CVA important even if you already know where they had the stroke
everyone’s neuroanatomy is different and might present differently
- depending on variations in circulation and collateral flow anatomy
what are 8 general features of a CVA and why
impaired motor control
sensory deficits
*inc DTRs
*altered ms tone
*path reflexes
secondary weakness, impaired ROM, dec balance
UMNL
what is critically important in a dx of a CVA
TIME = brain
rapid dx and intervention
what scan is more commonly utilized when dx a CVA in an ED
CT scan
pros and cons of a CT scan as a CVA diagnostic tool in the ED
pros:
- quickly show if hemorrhagic or ischemic (quicker than MRIs)
- more readily available than MRIs in ED
- easier to monitor person during CT than an MRI
cons: less specificity/sensitivity than MRIs
- might not show brain abnormalities right away
- could miss stroke if not timed well
- hard time detecting smaller arteries
use of MRI after stroke dx
person w stroke will always get an MRI to assess extent of neurologic damage in a completed stroke
- question will be when
pros and cons of MRIs as a CVA diagnostic tool in the ED
pros:
- detect smaller arteries (esp important when assessing above brainstem)
- more accurate in detecting acute stroke than CT
- greater detail provided
cons:
- less accessible in ED
- more contraindications
- can be safety issue - harder to monitor person in MRI
what are 4 other dx medical tests to do other than scans
- blood tests: coag, blood sugar
- hypoglycemia can present similarly to stroke - angiogram
- US (carotid) - looking to identify any plaque formation in arteries
- ECG
how do CT scans work and how will they show ischemic vs hemorrhagic strokes
same principles as XRs
- fluid filled cavities don’t absorb as much so will show up as more black
- blood is more dense and shows up whiter
hemorrhagic strokes - show up bright white
ischemic strokes - darker than normal brain (less dense)
what is the best best imaging tool to use to see the full extent of a stroke
MRIs w diffusion/perfusion and contrast
how do MRI scans work and how will they show ischemic vs hemorrhagic strokes
magnetic field
ischemic strokes = white
hemorrhagic strokes will show up white, but not as localized or dense as on CT
- see it running thru the area
what is the gold standard screening tool used by trained ED MDs and RNs for stroke dx
NIHSS
- national institutes of health stroke scale
what is the NIHSS
gold standard
initial and serial exam of impairments
can link neuroanatomy to sx and what part of brain impacted by stroke
- quantifies severity of stroke and nature of deficits
when is the NIHSS conducted
anyone suspected of stroke
done in intervals
- baseline
- 2hrs post
- 24hrs post
- 1-2wks later
what are the results of NIHSS helpful w
acute management
prognostic outcomes and dc
- <6 good outcome, low disability
- >/=16 high mortality rate, and inc disability
what is the goal of medical management of an ischemic stroke
restore blood flow to ischemic tissue that is receiving enough blood to survive, but not to function (penumbra)
what is the ischemic core
dead neurologic tissue
- necrotic in nature
- won’t regain function
what is the penumbra
ischemic tissue around the core that is still viable
- not full function bc not full O2 perfusion
- want to restore O2 asap so can regain function of penumbra
what types of medical management interventions are utilized w ischemic stroke
pharmacological management
surgical removal of clot
- corkscrew, suction
manage treatable risk factors (ie cardiac dz)
what ischemic strokes is surgical medical management appropriate for
large vessel occlusions
what pharmacological intervention is utilized w ischemic strokes
tPa
what is tPa and what are characteristics of using this as management of an ischemic stroke
tissue plasminogen activator
- effective if given w/i 3hr of onset
- inc risk of hemorrhagic transformation -> needs to be monitored closely
what is the goal of medical management of hemorrhagic strokes
dec the high ICP and edema
what are medical management interventions to dec ICP in hemorrhagic strokes
craniotomy or surgical decompression
VP shunt/drain
what role does neurosurgery have in the management of hemorrhagic strokes
coil or clamp the aneurysm/AVM
what are other medical interventions (that are nonsurgical) for hemorrhagic strokes
manage ICP w HOB elevation
meds
vit K infusions - promote clotting
where is the most common place for an aneurysm
ant communicating a.
what is the goal of medical management for a TIA
prevent a stroke
what are medical interventions utilized in managing a TIA
treat risk factors to dec risk of future strokes
- HTN, hyperlipid, DM, afib
- ASA, anticoag, BP meds, statins, antispasmodics
lifestyle modification
- nutrition, exercise, stress
what are medical interventions for strokes in general when managed acutely (8)
- prevent re-bleed, manage ICP
- CO, BP, cerebral perfusion, respiration
- sz prevention
- bowel and bladder function
- skin integ
- DVT prevention
- infection control
- nutrition, electrolyte balance
ICP level is a greater concern in which type of stroke and why
hemorrhagic
watch for midline shift or herniation
why are anti-sz meds often prescribed for pts after a stroke
stroke or brain injury in risk of pt having a sz d/t pressure and edema from strokes/TBIs result in abnormal cell mechanisms
- high risk of sz
