Clinical Care: Stokes Flashcards
Two major branches Internal Carotid Arteries
1) Anterior cerebral artery (ACA)
2) Middle cerebral artery (MCA)
(a) Two arteries fuse to become the basilar artery
(b) Supplies the Cerebellum and Brainstem
Vertebral - Basilar Arteries
1) The PCA connects internal carotid artery and vertebral basilar arteries
2) The ACA connects the anterior cerebral arteries
3) The MCA is a direct branch off of the internal carotid artery
Circle of Willis
Rupture of a blood vessel causing bleeding into the brain and lack of cerebral blood flow leading to ischemia
Hemorrhagic stroke
Blockage of a blood vessel causing lack of cerebral blood flow leading to ischemia
Ischemic stroke
is the acute neurologic injury that occurs as the result of the interrupted blood flow to the brain
“stroke”
80% of strokes are
ischemic
Can Ischemic and hemorrhagic be distinguished without exam?
Cannot distinguish between the two based on clinical criteria
-3rd leading medical cause of death
-2nd most frequent cause of neurologic morbidity
-Risk factors are HTN, atherosclerosis and age
stroke
- obstruction of an artery due to a blockage that forms in the vessel
Ischemic Stroke: Thrombotic
- obstruction of an artery due to a blockage from debris that has broken off from a distal area
Ischemic Stroke: Embolic
- lack of brain blood flow to decreased systemic
blood flow
Ischemic Stroke: Systemic hypo perfusion
a transient episode of neurologic
dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction (previously was reversible neurologic dysfunction that resolved within 24 hours, however that criteria has been replaced with the above).
Transient ischemic attack TIA
is a stroke is defined as neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia with infarction
(tissue death) of central nervous system tissue.
Cerebral Vascular Accident (CVA)
The only way to determine the difference is by
MRI
“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 hemorrhage bleeds directly into the brain tissue
Intracerebral hemorrhage
What hemorrhage bleeds into the subarachnoid space
Subarachnoid hemorrhage
(a) Depends on the site of bleed
(b) Intracerebral hemorrhage usually has gradual onset as blood builds
(c) SAH has maximal impact right away usually with intense “worse headache of my life” headache
(d) Headache, vomiting, decreased level of consciousness occurs in about half the
patients with ICH
(e) Symptoms tend to worsen gradually overtime
Hemorrhagic Strokes or Intracranial Hemorrhage (ICH):
Clinical Manifestations
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 Finherstick blood glucose
d) O2 sat
4) Imaging
a) Helps to differentiate between ischemic and hemorrhagic stroke
b) Non-contrast CT
c) MRI
5) Blood pressure
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%
d) 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
e) Monitor BP every 15 minutes
7) Medication
a) Aspirin 325mg
8) MEDEVAC!
Initial interventions for ischemic stroke
“Cerebrovascular disease including stroke, transient ischemic attack, and vascular malformation is disqualifying.”
Overall Disposition: MANMED 15-106
for papilledema which may indicate increased
intracranial pressure
Fundoscopic examination
Suspect stroke
Differential blood pressure readings between upper extremities may indicate an aortic dissection
