Acute ischemic stroke Flashcards
What is the name of a partial seizure with post-ictal hemiparesis? (can often mimic a stroke)
Todd’s paralysis
Pick the initial 4 labs and 2 studies to get when you suspect a stroke or need to rule out a ischemic stroke
4 labs: CBC, Chemistries (especially glucose), PT/INR/PTT, cardiac biomarkers (CK, trop-1). 12 lead ECG, noncontrast CT brain
Should you give T-PA if CT scan shows subacute ischemia?
no
What is the area/zone describing reversible ischemia around a core of irreversible infarction?
Penumbra
For how long is the Penumbra salvageable after an ischemic stroke onset?
first few hours
What things damage the penumbra? (4)
hypoperfusion, hyperglycemia, fever, seizure
Why might a blood pressure be elevated in stroke?
trying to maintain perfusion to penumbra (we don’t always want to lower BP with ischemic stroke)
To use IV t-PA, below how many hours after symptom onset can we use the medication?
3 (with brain CT corroborating acute ischemic stroke <3 hrs old)
What are some contraindications of using t-PA besides timing? (Including cut offs for recent MI/stroke, recent surgery, coag levels, platelet levels, glucose levels, and BP levels)
seizure, symptoms are minor or they are rapidly improving, head trauma, recent stroke/MI (3 mo), recent major surgery (2wks), acute chest/back pain, h/o intracranial hemorrhage, abn PT/INR (>1.7), platelets <100000, glucose <50, BP >185/110.
What is the dosing of tPA? and over how many hours?
0.9mg/kg (max 90mg). 10% as bolus, remaining 90% infused over 1 hour.
T-PA is less effective if blood glucose is over what level?
150mg/dL
T-PA when given properly decreases risk of disability by how much? Increases ICH risk by how much?
30% decreased disability risk, 5% ICH risk
above which blood pressure do we NOT LOWER BP OR GIVE IV TPA
220/120
What two drugs can we use to lower the BP for TPA patients?
nicardipine, labetalol
How do we dose nicardipine for TPA if we need to lower BP slightly?
5mg/hr IV infusion (increasing 2.5mg/hr ever 5 min to max of 15mg/hr)
How do we dose labetalol for TPA if we need to lower BP slightly?
10-20 mg IV blous, may repeat every 10-15 min
To protect the penumbra, above what MAP is ideal for BP? what glucose? What O2?
> 100 MAP, glucose <150, O2 >95%
Start with what noninvasive evaluations for stroke etiology?
MRI brain/MRA, carotid duplex, transthoracic echo
Invasive evaluations after negative noninvasive ones include…?
transesophageal echo, cerebral angio
Who gets hypercoagulable workup when they have acute ischemic stroke?
young patients <55 with no identifiable source
What is the most common mechanisms of ischemic stroke?
Clot forms somewhere else and travels to brain - thromboembolism. Other causes: cardioembolism, larger artery atherosclerosis, hypercoag state, nonatherosclerotic vasculopathy, small vessel disease, hypotension
Non FDA approved therapy that you can give within 6 hours of strok eonset is what?
intra-arterial t-PA (different from standard IV t-PA)
What is the corkscrew device that removes embolus that is FDA approved but has controlled trials pending?
Merci retriever
What medication can lower mortality and morbidity if started within 48 hours of ischemic stroke?
aspirin (no evidence for using heparin)
What secondary stroke prevention for anti-thrombotic therapy do we use for large artery atherosclerosis and small vessel disease?
antiplatelet therapy (these are platelet clots!): aspirin 50-325mg QD, clopidogrel (plavix) 75mg daily, ASA plus dipyridamole XR (aggrenox) 25/200mg BID
What secondary stroke prevention for anti-thrombotic therapy do we use for cardioembolism, hypercoagulable state?
clotting factor clots so anticoagulation: warfarin (Coumadin) but have to wait at least 24 hours and begin IV heparin with goal PTT 50-70 if TPA given, after that, then you can start warfarin 5mg PO daily and titrate to iNR 2-3
What can we do for stroke prevention if there is carotid stenosis 50-99% with symptoms?
carotid endarterectomy, angioplasty and stenting only in high risk patients
