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33 Cards in this Set
- Front
- Back
normal amount of CSF?
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75-100mL
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average cerebral blood flow?
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50mL/100g/min
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what is the net gradient causing flow in the brain?
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cerebral perfusion pressure (CPP= MAP -- ICP)
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normal CPP?
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100mmHg
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what happens when the MAP gets <20mmHg?
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EEG flat, irreversible damage
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what is pressure-flow autoregulation?
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cerebral flow remains relatively constant despite huge changes in body blood pressure
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what does breathing in a bag do for cerebral blood flow?
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increases it by increases pCO2 & causing vasodilation
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what does hyperventilating do for cerebral blood flow?
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decreases it by decreasing pCO2 & causing vasoconstriction
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what is normal ICP?
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~5-10mmHg
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what is the bodies response to high ICP?
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initially- min change in ICP, decrease CSF
eventually- ICP increases, CPP decreases, ischemia :( |
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symptoms of MILDLY increased ICP?
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headache, irritable, nausea, vomit, confusion
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symptoms of MODERATELY increased ICP?
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disturbed consciousness, hypertension, bradycardia, irregular respiration
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symptoms of SEVERELY increased ICP?
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cardio collapse, coma, respiratory depression, dilated pupils
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where does a cerebral herniation typically occur?
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foramen occipitalis
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what happens during a cerebral herniation?
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tissue/CSF/vessels forced OUT of cranium
leads to cardiorespiratory arrest |
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on the compliance curve of ICP vs. volume... what do the #s represent?
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1 & 2 represent compensation. 3 & 4 represent decompensation-->herniation
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what is considered severe brain swelling?
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ICP of 30mmHg
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what drugs are given for IV anesthesia?
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propofol & barbituates
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what drugs are given for inhalation anesthesia?
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isoflurane & sevoflurane (volatile)
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propofol uses what inhibitory neurotransmitter?
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increases GABA length of action on Cl- channels
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what effects does propofol have on the patient?
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decreased cerebral metabolic rate, decreased blood flow, decreased ICP
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what neurotransmitter do barbituates mimic?
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GABA, activate Cl- channels
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what effects does propofol have on the patient?
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vasoconstriction, decreased CBF, dec volume, dec ICP, depresses RAS
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barbituates put the patient into a protection _____
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coma
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the reticular activating system (RAS) controls what?
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wakefulness, sleep, consciousness
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T/F: the mechanisms of the volatile gas anesthesias are unknown
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true
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what is the only drug given for an awake craniotomy?
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analgesic for the dura
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benzodiazapenes are what type of drug?
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amnestics
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what neurotransmitter do benzodiazapenes enhance?
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Cl- channel gating function of GABA
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how do benzodiazapenes effect the patient?
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anterograde, dec anxiety, dec CBF
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opioids are what type of drug?
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analgesic
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what drug is 100 times more potent than morphine?
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fentanyl
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what do opioids mimic?
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endorphins to activate the pain modulating system
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