Increased ICP Flashcards
normal icp values
adults 4-15 mmhg
children 3-7 mmhg
infants 1.5-6 mmhg
increased >20 cmh2o / >15 mmhg
monro kellie doctrine
brain, csf, and blood are incompressible
change in volume -> damage to others
inc. brain vol -> dec. blood volume -> dec CSF
compliance vs elastance
compliance: quality of distensibility available within intracranial contents that enable them to adapt to lesions
elastance: resistance of contents to the expansion of mass
defect and presentation of subfalcine or cingulate herniation
defect: compression of internal cerebral vein and anterior cerebral artery
presentation: contralateral hemiparesis
defect and resentation of central transtentorial herniation
page 2 (4 items)
defect in uncal herniation
compression of midbrain, 3rd nerve, pca
defect and presentation of tonsillar herniation
page 3
normal cpp
60-80 mmhg
< 50 cerebral ischemia
< 30 brain death
cbf values
n: 50 ml/min/100g
10-15 ml/100g/min reversible ischemia
<10-15 irreversible ischemia
normal map
50-150 mmhg
> 150 increase cbf, constricted
<50 decreased cbf, dilated
normal hourly and daily rate of csf production
20 ml/hr
450-500 ml/day
triad in increased icp
headache*
vomiting
papilledema (most reliable sign, fundoscopy)
t/f papilledema does not affect visual acuity
true
vital signs in increased icp
triad: hpn, bradycardia, bradypnea
pain, agitation, blood loss -> paradoxic tachycardia
focal deficits in increased icp
decreased consciousness and mental status
cardiac dysrhtymias
pupillary abnormalities
bilateral rectus palsy
icp >40-50 mmhg -> dec blood flow -> global ischemiai -> dec consciousness