Clinical Care- Strokes Flashcards
internal carotid arteries branch from what?
common carotid artery
what are the two major branches of the internal carotid artery
anterior cerebral artery ACA
middle cerebral artery MCA
after the two vertebral arteries fuse to become the basilar artery where do they branch off?
branches off to become the right and left posterior cerebral arteries
what does the verterbral basial arteries supply
cerebellum and brainstem
the anterior communicator artery connects what?
the anterior cerebral arteries
The posterior cerebral arteries (PCA) connects internal carotid artery and what?
the vertebral basilar arteries
the MCA is a direct branch off of what artery ?
internal carotid artery
definition of a stroke
acute neurological injury that occurs as the result of the interrupted blood flow to the brain
definition of a hemorrhagic stroke
rupture of a blood vessel causing bleeding into the brain and lack of cerebral blood flow leading to ischemia
definition of ischemic stroke
blockage of a blood vessel causing lack of cerebral blood flow leading to ischemia.
subtypes of ischemic stroke
thrombotic
embolic
systemic hypo perfusion
what is an obstruction of an artery due to a blockage that forms in the vessel
thrombosis
what is an obstruction of an artery due to a blockage from debris that has broken off from a distal area
embolism
what is lack of brain blood flow (due?) to decreased systemic blood flow?
systemic hypoperfusion
definition of a TIA
defined as a transient episode of neurologic dysfunction caused by focal brain, spinal cord or retinal ischemia (without acute infarction)
CVA is defined as what?
neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia WITH infarction
what is the only way to differentiate between TIA and CVA ?
MRI
what is the clinical manifestations of ischemic stroke
depends on the site.
in general, sudden onset focal neurological disorder.
more general diffuse finding for systemic hypo perfusion etiology.
FASTER mneumonic
1) Face – drooping or numbness on one side of the face
2) Arms – one limb being weaker or more numb than the other
3) Stability – steadiness on feet
4) Talking – slurring, garbled, nonsensical words, inability to respond
normally
5) Eyes – visual changes
6) React – MEDEVAC immediately and note time of symptom onset
what are some risk factors of ischemic stroke
(a) History of vascular disease
(b) Atrial fibrillation (not on meds)
(c) Atrial septal defect (ASD)
(d) Ventricular septal defect (VSD) with deep vein thrombosis (DVT)
(e) Recent myocardial infarction
(f) Atherosclerosis
(g) Clotting disorders
What are the two subtypes of Hemorrhagic Strokes or Intracranial Hemorrhage (ICH)?
1) Intracerebral hemorrhage bleeds directly into the brain tissue
2) Subarachnoid hemorrhage bleeds into the subarachnoid space
the clinical manifestation of this hemorrhagic stroke or ICH has maximal impact right away and usually with intense “worse headache of my life” headache?
SAH
the clinical manifestation of this hemorrhagic stroke or ICH usually has a gradual onset as blood builds:
Intracerebral hemorrhage
Headache, vomiting, decreased LOC occurs in about half the patients with ICH.
Risk factors for Hemorrhagic stroke or ICH?
hypertension trauma bleeding disorders drug use (cocaine, meth) vascular malformations (aneurysms)
patient management of both hemorrhagic and ischemic stroke
hx and physical
(exclude other causes: seizures, migraine, and hypoglycemia)
look for sources of emboli
(DVT, carotid bruits)
Thorough fundoscopic examination
1) Fundoscopic examination for papilledema which may indicate increased intracranial pressure
2) Thorough examination for signs of trauma
3) A tongue laceration (may have trauma from seizure)
4) Differential blood pressure readings between upper extremities may indicate an aortic dissection
Initial interventions for ischemic stroke
1) Maintain oxygenation > 94%
a) Do not give oxygenation to non-hypoxic patients
2) Elevate head of bed to ~30 degree
3) Labs:
a) EKG
b) CBC
c) FBG
d) O2 sat
4) Imaging
a) Helps to differentiate between ischemic and hemorrhagic stroke
b) Non-contrast CT
c) MRI
5) Blood pressure
considerations for blood pressure in ischemic stroke
a) May be cause of stroke or spike in response to blockage/stress
b) Do not lower it acutely as it may be the only thing maintaining adequate perfusion
c) UNLESS pressure is above systolic of 220 and/or diastolic of 120 in which case you should lower the pressure by 15%
What drug are we giving for ischemic stroke?
Labetalol (Trandate) - non-selective beta blocker
(1 Dosing: 10-20 mg IV, may give same or double dose every 10-20 minutes to max of 150mg
Adverse reactions and contraindications of Labetalol for stroke
Adverse Reactions: Orthostatic hypotension, fever, hepatotoxicity, fatigue, dizziness, bronchospasm, fatigue, depression
Contraindications: Sinus brady, heart blocks, bronchospastic disease, uncompensated CHF
what kind of labs will we be taking for ischemic stroke
EKG, CBC, Finger stick blood glucose, 02 Sat
what additional medication is indicated besides labetalol for ischemic stroke?
aspirin 325 mg
Treatment of TIA?
If thorough Neuro exam reveals no abnormalities, can give Aspirin with MO guidance
