NEUROLOGY Part 1-2 Flashcards
Understand ICP, CBF, and strokes.
What is the normal ICP range?
5-15 mmHg
What are the 3 components of the skull (from most to least %)?
Brain tissue, Cerebrospinal fluid, blood
What does the modified Monro-Kellie doctrine state?
The volume of the brain is constant. When one component increases the others decrease to adapt.
What is autoregulation?
The maintenance of constant blood flow to the brain > Cerebral blood vessels constrict or dilate to control CBF.
What is cerebral mean arterial pressure (MAP) and its normal range?
How we measure autoregulation.
5-15 mmHg ?
How do you calculate MAP?
When should you be concerned?
What do you do in these cases?
(SBP + 2(DBP)) / 3
Less than 50 mmHg - give fluids
More than 150 mmHg - remove fluids
How do you calculate cerebral blood flow (CBF)?
What is the normal range?
Find cerebral perfusion pressure (CPP) = MAP - ICP
Normal = 70 - 100 mmHg
What ICP value is concerning?
What are the implications?
- MORE than 20 mmHg (norm 5-15).
- Decreased CPP, increased risk of brain ischemia/infarction, poor prognosis.
What are the types of cerebral edema?
What causes them?
- Vasogenic (V=vessels) - fluid leaks from capillaries into extracellular space.
- Cytotoxic (C=cells) - fluids shifts from extracellular to intracellular. Brain cells swell!
What does Cushing’s triad indicate?
What are the 3 components?
Indicates IICP.
1. Hypertension (widened pulse pressure)
2. Bradycardia (w/ bounding pulse)
3. Irregular/decreased respirations
Compare early and late signs of IICP.
- Altered LOC vs. Decreased LOC
- Altered breathing pattern vs. ineffective breathing
- Unilaterial hemiparesis vs. abnormal motor response (posturing)
- Unitlaterial pupillary changes vs. bilaterial (sometimes)
What is the difference between hemiparesis and hemiplegia?
HemipareSIS = SIS is NOT paralysis; **partial weakness **on one side of the body
Hemiplegia = complete paralysis of one side of the body
Three things…
What do you always prioritize as a nurse?
ABCs - Airway, breathing, circulation
What is a cerebral vascular accident (CVA)?
A stroke - sudden decrease in blood flow to an area of the brain (ischemia).
What are the two main types of strokes?
What causes them?
Which is most common?
- Ischemic stroke (85% of strokes) = vessel or artery is occluded.
- Hemorrhagic stroke = there is a bleed causing IICP.
What are the types of Ischemic strokes?
What causes them?
- Thrombotic stroke = plaque reduces blood flow through the artery (stenosis)
- Embolic stroke = a clot (from outside the brain) has blocked blood flow through the artery
What are the types of Hemorrhagic stroke?
What causes them?
- Intracerebral hemorrhage = cranial vessel tears. Bleeds into brain tissue > IICP. InTra = Tear
- Subarachnoid hemorrhage = cerebral aneurysm ruptures. Bleeds into subarachnoid space > IICP. ArAch = aneursym
What is the crucial time frame for restoring blood flow to the brain?
for a stroke
2-3 hours after symptoms began.
Recovery is still possible!
What is the most concerning stroke symptom?
‘Worst headache of my life’
Indicates IICP
What are the most common symptoms of a stroke?
acronym
FAST - facial dropping, arm movement, slurred speech, time
Differentiate right and left sided stroke manifestations.
What are you concerned about?
Right = wrong judgement; impulsive (concerned with safety)
Left = Language and speech (impaired understanding and memory)
What two main assessments/scales should be used for stroke patients?
Aside from basic focused ones
-
Glasgow coma scale
Canadian - Neurological assessment
What medications can/cannot be given for certain strokes?
big no no!
- Thrombotic stroke = tPA within 3 hours, anticoagulants
- Hemorrhagic stroke = DO NOT administer anticoagulants; already bleeding! Requires surgery.
What is the difference between a CVA and a TIA?
2 main differences
- TIA is a temporary sudden decrease of blood flow to the brain. No necrosis/infarction occurs.
- CVA is a lasting sudden decrease in blood flow causing necrosis.
