Stroke 2 Flashcards
In AIS (arterial ischemic stroke), what is a normal response of the body? What should you do about it?
High BP, DO NOT lower it
- BP increases due to arterial occlusion (in effort to perfuse the penumbra)
- Lowering BP will starve the penumbra and worsens outcome!
Cerebral Blood FLow to Save Penumbra
(ml/100g/min)
- Over 18
- 8-18
- Below 8
- Normal function
- Neuronal dysfunction
- Neuronal death
Extent of Ischemic Injury
Window of Opportunity - Ischemic Penumbra
- Viability of brain tissue is preserved if perfusion is restored within a critical time period of ____.
2 - 4 hours
What is a complication of stroke from suddenly restoring blood flow/pressure?
Hemorrhagic Stroke (Red Infarct)
Pathophys of AIS & TIA
- Usually ____ (blood clot forms in vascular system, travels downstream, plugs the ____)
- thromboembolism / cerebral artery
What is the acute therapy for AIS & TIA?
Thrombolysis or Thrombectomy
(DO NOT LOWER BP)!!!***
- No infarction and no sequaelae
- Infarction w/ sequelae
- TIA
- Ischemic stroke
4 options for secondary prevention of AIS & TIA
- Antithrombotic therapy
- Vascular risk factor therapy
- Carotid endarterectomy (CEA)
- Carotid angioplasy
- what is tPA?
- What do you need to know before administering?
- Tissue Plasminogen Activator
- Time of onset & Contraindications
What is the time frame for administering tPA?
3 - 4.5 hours
3 inclusion criteria for tx Acute Ischemic Stroke w/ tPA
- Clinical dx of ischemic stroke causing measurable neurologic deficit
- Onset of sxs <4.5 hrs (if exact time not known, defined as last time pt was normal)
- 18 years of age or older
Historical Contraindications for giving tPA
- Stroke or head trauma in the past 3 months
- Previous intracranial hemorrhage
- Intracranial neoplasm, arteriovenous malformation, or aneurysm
- Recent intracranial / intraspinal surgery
- Arterial puncture at non-compressible site in previous 7 days
Clinical Contraindications of giving tPA
- Sxs suggestive of subarachnoid hemorrhage
- Persistent BP evelation 185/110
- Serum glucose <50
- Active internal bleeding
- Acute bleeding diathesis (hematologic)
Hematologic contraindications of giving tPA
- Platelet count <100,000
- Current anticoagulant use
- Heparin use within 48 hrs
- Current use of direct thrombin inhibitor
Findings on head CT Contraindications for giving tPA
- Evidence of hemorrhage
- Extensive regions of obvious hypodensity consistent w/ irreversible injury
Contraindications for giving tPA
- Minor / isolated neuro signs
- Rapidly improving sxs
- Major surgery / serious trauma in previous ___
- GI or urinary tract bleed in previous ___
- MI in previous ___
- Sz at onset of stroke w/ post-ictal neuro impairments
- Pregnancy
- Age ___
- Severe stroke of NIHSS score >___
- Combo of both previous ischemic stroke and ___.
- Surg: 14 days
- Bleed: 21 days
- MI: 3 months
- over 80 y/o
- NIHSS score >25
- DM
BP and Stroke
- Perfusion pressure distal to obstruction is ___ and dependent on systemic BP
- BP is usually ____ in acute stroke & may maintain perfusion to borderline ischemic areas
- BP >____ increases risk of recurrent ischemic stroke
- BP <____ is associated w/ excess deaths***
- low
- elevated
- >200
- <120 –> deaths (from coronary disease)
- Acute MI
- CHF
Aortic dissection - HTN encephalopathy
- Candidate for thrombolysis & BP >185/110
Indications to decrease BP emergently in AIS
Intracranial hemorrhage occurs most often in NIHSS score over ___.
20
3 contraindications of treatment w/ tPA
- Over 80 y/o
- On Warfarin
- NIHSS >25
3 things to do within 10 mins at triage
- Review tPA criteria
- Page acute stroke team
- Draw pre-tPA labs, but do not let this delay care
4 things to do within 25 mins for Medical Care
- O2 / BP / Weight / NIHSS
- 2 IVs
- 12 lead ECG
-
CT
- bleed (no tPA)
- bleed (give tPA)
What should be completed within the first 45 mins?
CT and Labs
- obtain lab results
- read CT
- return pt to ED
What should be completed within the first 60 mins?
Treatment
- Start IV tPA (if indicated)
- Monitor for ICH sxs (HTN, HA, N/V, decreased neuro status)
- Often used in adjunct w/ tPA
- MERCI retrieval system is corkscrew like apparatus designed to remove clots from vessels
- PENUMBRA system aspirates the clot
Mechanical Thrombolysis
What is the biggest predictor of Hemorrhagic Transformation? 5 total
(ischemic –> hemorrhage)
- Size of infarction #1
- A-fib
- NIHSS score high
- Hyperglycemia
- Thrombocytopenia (low platelets)
Hemorrhagic Stroke (15% of all strokes)
- What is the primary cause (70-90%)
- What is secondary cause (10-30%)
- Manifests w/ sxs of _____
- Primary: HTN
- Secondary: Vascular malformation (aneurysm, AVM, tumor, amyloid angiopathy, thrombolytic agents)
- Increased ICP (intracranial pressure)
Which stroke?
- Non-contrast CT + for bleed
- 50% mortality (80% w/ permanent disability)
- ICP monitoring
- Neurosurgical intervention
Hemorrhagic
- Directly diverts blood from arteries –> veins
- May bypass brain tissue & cause chronic ischemia
- Congenital, but not genetic!
- Concern of weakened wall –> dilation–> increased risk of rupture
Arteriovenous Malformations (AVMs)
- Enlargement of blood vessel due to wall weakening
- >___ y/o
- 4 sizes
Cerebral Aneurysm
- >40 yrs
- small, medium, large, giant
What are the most common sites of Cerebral Aneurysms?
At bifurcations
(anterior communicating artery) –> optic chiasm
(Posterior communicating artery)
Sxs of Hemorrhagic or Ischemic?
- Diastolic BP >110
- HA
- Vomiting
- Coma
- Neck stiffness
- Seizures
Hemorrhagic / aneurysms?
3 common CNS Herniations
- Subfalcine
- Transtentorial
- Tonsillar
Which CNS Herniation?
- Common, HA, contralateral leg weakness
Subfalcine
Which CNS Herniation?
- Oculomotor (CN 3) paresis w/ ipsilateral dilated pupil, abnormal EOM’s
- Contralateral hemiparesis
Transtentorial
Which CNS Herniation?
- Obtundation
Tonsillar
Brain Herniation
- Life threatening
- Increased ICP may cause ____.
- Triad?
Cushing reflex
- HTN
- Bradycardia
- Abnormal respirations
2 tx options for cerebral aneurysm
- Endovascular (coil embolization)
- Surgery (clip)
2 causes of SAH
- Aneurysm in Circle of Willis
- AVM since birth
Presentation of SAH
- Often w/o warning, but may have had prior ___ or ____
- Sudden increases in ____
- Maybe associated w/ ____
- NOT ____
- bleeds / HAs
- ICP
- Valsalva
- ICH
Dx for SAH
- CT w/o contrast
- if negative (no bleed), then get an LP
Hemolyzed blood in CSF (golden yellow) indicating the presence of bilirubin in the cerebrospinal fluid (CSF) and is used by some to differentiate in vivo hemorrhage from a traumatic LP.
- Takes how long to lyse and change color?
Xanthochromia
- 1-2 hours
Tx of SAH
- Decrease ICP w/ what 6 things?
- Treat and monitor vasospasm w/ what med?
- stool softeners
- cough suppressants
- anxiolytics
- analgesics
- antiemetics
- Keep HOB elevated (head of bed)
Vasospasm: CCB
- “crescent shape”
- Blood outside of brain, but in skull (pushes on brain)
Subdural hematoma
“lemon”
Epidural hematoma
1st or 2nd tier of Acute Stroke Management?
- CBC, BMP, Glucose, PT/PTT, ESR
- EKG
- Head CT w/o contrast
1st
1st or 2nd tier of Acute Stroke Management?
- Non-invasive imaging of carotids (doppler US)
- TTE or TEE (localize where clot came from)
- MRI/MRA
- CSF eval
- Cerebral angiogram
2nd
Hyperglycemia & Acute Stroke / DM & secondary stroke prevention
- Peri-stroke hyperglycemia is associated w/ ____ clinical outcomes
- Inpatient goal of BG is <____
- Chronically, each decrease in % in Hgb A1C results in significant reduction of what 4 things?
- Outpatient goal of Hgb A1C is < __
- worse
- 150
- death, MI, vascular complications, stroke risk
- 7.0
