Neuro Exam 3 Flashcards
(114 cards)
intracranial compliance
ability of body to compensate for increased intracranial pressure
increased intracranial pressure
occurs when brain tissue, CSF, or blood increase causing the other components to decrease –> further injury r/t compression of tissue
causes of IICP
injury
bleeding
hematoma
hydrocephalus
tumor
encephalitis / meningitis
factors that influence ICP
body temp
oxygenation status
body position
arterial / venous pressure
vomiting / bearing down –> pressure in intra-abd wall
normal ICP
0-15 mmHg
increased ICP range
pressure > 20 mmHg for 5 min or more
**sustained IICP = herniation
cerebral perfusion pressure (CPP)
pressure that pushed blood to the brain
**when it is too low the brain is not perfused –> brain tissue DEATH
CPP range
60-100 mmHg
**MUST be maintained at 70 for those with brain injury
CPP formula
CPP = MAP - ICP
early s/s of IICP
DECREASED LOC!!!
restless
confused
not responding
**any mental status changes are early sign
late s/s of IICP
irregular breathing - Cheyne Stokes hyperventilation –> apnea!!!
Cushing’s Triad
babinski reflex
HA
seizure
posturing
doll’s eye
vomiting
Cushing’s triad
increased systolic BP / decreased diastolic BP
bradycardia
irregular RR
decerebrate posturing
arms beside body
hands flexed
forearm pronated
**more ominous posture
decorticate posture
arms pulled into body , hands flexed
IICP monitoring
catheter or sensor
-subarachnoid bolt
-intraparenchymal sensor
-intraventricular catheter
subarachnoid bolt
bolt / screw inserted into hole drilled into skull and threaded into place at inner table of skull
-decrease infection risk
-inability to drain CSF, risk of bolt becoming occluded w/ blood, tissue, dura
-increase risk of drifting
intraparenchymal sensor
inserted below dura into white matter of frontal lobe
-less drifting overtime
-CSF not able to drain
intraventricular catheter
used for monitoring ICP and DRAINING CSF
-MUST be leveled to external auditory meatus of ear
-drainage controlled by raising or lowering collection burette
-high infection risk and bleeding
IICP dx labs
ABGs
CBC
coagulation
electrolytes
serum osmolality
urinalysis and osmolality
IICP dx tests
CT
MRI
cerebral blood flow with transcranial doppler
EEG
IICP surgical management
remove section of cranium and dura to allow space for swelling brain
**hemicraniectomy
IICP medical management
- oxygenation
- diuretics
- fluids
- BP management
- seizure precautions
IICP oxygenation
-mechanical ventilation
-MAINTAIN PaO2 > 80 mmHg
-MAINTAIN PaCO2 > 35-45 mmHg
**DO NOT allow hyperventilation
IICP diuretics
reduce brain tissue volume
-osmotic = mannitol and hypertonic saline
-loop = lasix