Exam 2: Stroke Flashcards
Transient Ischemic Attack definition
Cerebral ischemic event lasting less than 24 hours (typically only minutes) without apparent permanent neurological deficit
Clot self destruct in time
Completed Stroke definition
Cerebral ischemic acute event with deficit that persists
Lasting symptoms from tissue hypoxia despite restoration of perfusion
Clot does not self destruct in time
What other etiologies can present as a stroke?
Some of the most common stroke mimics are seizures, migraine, fainting, serious infections and functional neurological disorder (FND).
Use of thrombolytic therapy (tPA) in stroke is for
Acute management of stroke tPA
Inclusion therapy for thrombolytics
Diagnosis of ischemic stroke causing measurable deficit
Onset of symptoms less than 4.5 hours prior to treatment
(3 hrs if patient ≥80 y/o!!)
age ≥18 y/0 (no peds!)
Exclusion criteria for thrombolytics
- ischemic stroke/significant head trauma within 3 months
- ANY hx intracranial hemorrhage
- intracranial neoplasm, AVM, aneurysm
- Active internal bleeding
- ELEVATED BP >185/110
- INR >1.7
- Use of direct thrombin inhibitors/direct factor Xa inhibitors
- use of heparin within 48 hrs + elevated aPPT
- BG < 50 mg/dL
- Plt < 100,000
Relative exclusion criteria for tPA
- minor sx are rapidly improving
- seizure at onset – postictal neurologic deficit
- Major surgery/trauma in past 14 days
- Recent GI bleed (~21 days)
- Recent acute MI (~3 months)
additional tPA exclusion for time window: 3 hr – 4.5 hrs
if age >80
severe stroke (NIH score >25)
Hx of stroke AND diabetes
Metabolic rate of the brain
“the brain is a tyrant”
Tremendous O2 and energy demands, does little work
2% BW but receives 17% of CO and consumes 20% of O2
Grey Matter of brain
Lots of redundancies in cortical tissue supply at microvascular level
Capillary arborization
White matter of the brain
Occlusion = supply is cut off
Single penetration micro vessels
Types of strokes
71% Ischemic
26% Hemorrhagic
3% other
Ischemic stroke types
32% unknown
19% Lacunar
14% embolic
6% Thromboembolic
Hemorrhagic stroke types
13% SAH
13% ICH
Cumulative risk of stroke after TIA or complete stroke
A person who had a TIA is just as at risk of developing another stroke as someone who had a complete stroke
Treatable risk factors for stroke
- HTN
- HLD
- heart disease
- DM
- Cigarette smoking
- Excessive EtOH intake
- Physical inactivity
- Obesity
- Carotid bruit
- POST MENOPAUSAL HORMONE THERAPY (estrogen)
- Afib, CAD
Untreatable risk factors for stroke
- Age (>55)
- Sex (male)
- Race (hispanic)
- Prior stroke (personal hx)
- Heredity (family hx)
T/F: the number of strokes have not gone down, but the severity of strokes have
true
T/F most stroke risk factors are treatable by Rx interventions
true
Clinical presentation of carotid stroke/tia
- Unilateral weakness
- Unilateral sensory
- Aphasia (speaking/understanding)
- Monocular vision loss
- Transient global amnesia
Clinical presentation of vertebrobasilar stroke/tia
- BILATERAL weakness
- BILATERAL sensory
- BILATERAL vision complaints
- Diplopia
- Vertigo
- Ataxia w/o weakness
- Dysphagia
Antiplatelet therapy (secondary prevention)
Small vessel lacunar
Large vessel embolic
Large vessel thrombotic
Warfarin (secondary prevention)
Cardioembolic event
Drugs that block ADP
Clopidogrel (Plavix)
Prasugrel (Effient)
Ticagrelor (Brilinta)
Drug that inhibits COX and Thromboxane
Aspirin
Drug that inhibits plasma adenosine and platelet phosphodiesterase
Dipyridamole
How do you individualize antiplatelet therapy?
All are equally good statistically
Pick the one that suits the patient’s needs
- best ADR profile
- produces inhibition of aggregation in the patient
- use in lowest effective dose to reduce bleed risk
T/F GI bleeds are the result of SYSTEMIC inhibition of PGE, not a local GI irritation
True
Will enteric forms of aspirin decrease GI bleed risk?
NO
Asprin dosing
Start at 81mg (take a week to work)
If pt needs rapid antiplt therapy, give 325mg (within 4 hours)
Patients that warrant DAPT
- CA stents + new cerebral ischemia
- cerebral ischemia within 90 days of
- Afib but can’t use anticoagulant
- Cerebral vessel dissection
T/F ASA resistant patients are at increased risk for stroke
true
Middle cerebral artery infarct
disrupt 2/3 of flow from middle CA
CA infarction = catastrophic stroke
Lacunar infarct
multiple lacunar infarcts, usually periventricular
always small, in white matter of brain
Microvascular Ischemic White Matter Lesions
Nonspecific
Most subtle~
Often asymptomatic
Hard to detect
May become symptomatic if lesions become confluent
Less than optimal: Migraine hx
Aggrenox
dipyridamole/ASA
(worsens HA)
Less than optimal: rapid antiplt effect
If need fast, avoid low dose ASA or Clopidogrel
» do loading dose or lead in therapy
- ASA 325 response in 4 hours, follow up with 81
- Clopidogrel 75 takes 1 week
Less than optimal: Spastic colon or IBS or gastric ulcer
Avoid ASA
especially higher dose 325mg enteric form
Less than optimal: CCB
Avoid clopidogrel or prasugrel with amlodipine/nicardipine
2C19/3A4
DDI considerations for stroke ppx meds
if patient also needs
- chronic NSAID
- chronic PPI
- CCB
DAPT therapy considerations
- failure of monotherapy
- first 3-6 mon post stroke w/ high RF
- Afib w/ anticoags contraindicated (can only use antiplt)
ASA resistance approach
- Check compliance
- Remove drugs that compromise ASA effects
- Change
- Change EC to chewable or seltzer
- Change ASA dose
Drugs that compromise ASA effects
NSAIDs (other than celebrex)
some herbal supplements
What to do if patient has GERD and req. antiplt (plavix/prasugrel)?
Take off omeprazole.
Start famotidine or pantoprazole.
Plavix (clopidogrel) resistance approach
- minimize drugs that inhibit 3A4/2C19
- Sub with drugs with less P450 effect
- add meds that induce CYP activity
Common meds that influence CYP 3A4 or 2C19
- statins (rosuvastatin least likely to interfere)
- CCBs only (not BB/ACEi)
- Z drugs: ambien, lunesta, (sonata least likely)
- Glyburide (not glipizide or metformin)
- Enablex, Ditropan (not detrol/sanctura)
- PPI (except pantoprazole?)
What do you do if patient is truly resistant to both ASA and clopidogrel (plavix)
use Brilinta (ticagrelor)
90mg BID
T/F all cause mortality in the HEALTHY elderly population is higher for those taking daily ASA than those who received placebo
true
Acute stroke management
- emergent transport
- stabilization
- detailed hx from pt/witness
- PE
- imaging
- labs
NIH stroke scale purpose
gives idea of severity and location of stroke
>20 = severe deficit, no tPA
4-20 = mild-mod ideal for tPA
<4 = good prognosis, no tPA
NIH stroke scale measures s/s
visual changes
facial droop
motor fnc of arms/legs
limb ataxia
sensory changes
language
dysarthria
Acute stroke management goal
reperfusion asap
- reduce ongoing CNS injury
Acute stroke treatment options
- IV-tPA (within 2 hrs of stroke)
- Endovascular intervention
Both?
stroke time window <2 hrs
reversible deficits
stroke time window 2-6 hrs
some but incomplete recovery
stroke time window > 6 hours
little recovery
5 signs of stroke
balance is off
speech slurred/face droopy
vision all or partial loss
headache severe
Collecting stroke history
when were they last seen normal
has this happened before
do they have other conditions that can mimic stroke?
what medications do they take?
recent medical/surgical history
To give tPA, onset of sx must be <4.5 hrs. What if the patient is 80 years old?
must be within 3 hours!! they are greater risk
RIsk factors for bleeding (upon acute stroke tx w. thrombolytics)
if baseline NIH >20
Protocol deviations
- anticoag or antplt given within 24 hrs
- tPA given beyond 4 hrs
- elevated blood pressure (HTN)
Baseline serum glucose > 200 mg/dL
Advanced age
edema or mass effect on CT scan
s/s of cns bleeding
acute neurological change/deterioration
headache
n/v
acute HTN
change in alertness (lethargy)
Most important ADR of tPA is
intercerebral brain hemmorhage
~7% risk of symptomatic bleed in clinical trials
What do you use if patient is ineligible for IV tPA?
intra-arterial thrombolysis (IA)
How does dosing of IA tPA differ from IV tPA?
IA tPA is a lower dose ~20mg
When can we use IA tPA
when patient can’t use IV
symptom onset <6 hrs
MCA occlusions
When giving IV tPA, what are the blood pressure goals?
bp MUST be
< 180 systolic
< 110 diastolic
Agents of choice for BP lowering during acute stroke tx
labetalol 10-20 mg IV
- may repeat or double dose every 10 minutes
Nicardipine 5mg/hr IV titrated to effect
If patient is not a tPA candidate, is HTN permissive?
Want to value perfusion»_space; BP control
ALLOW BP up to 220 mmHg systolic
tPA
Alteplase
fibrin specific “clot busting”
Dosing tPA
0.9 mg/kg actual body weight
(MAX = 90mg)
- 10% given as initial bolus over 1 minute
Must keep BP<180 mmHg systolic for 24 hrs
