Brain injury

Question 1

what makes up the crainial content

Answer 1

• tissue makes up (80%) neurons, meninges
• blood (10%)
• CSF (10%)
• CSF and blood collectively apply pressure

Question 2

what applies the most pressure in the cranium

Answer 2

the tissues such as neurons and meninges

Question 3

the cranial content provides intracranial pressure what is the common intracranial pressure

Answer 3

5-15mmHg

Question 4

_________ changes in intracranial pressure can cause very serious problems

Answer 4

minor

Question 5

what is the monro kellie hypothesis

Answer 5

-minor volume increase in 1 component is compensated by decrease in volume of 1 or both remaining components (intracranial pressure will remain stable)

Question 6

patho of increased intracranial pressure

Answer 6

• usually from proliferating lesions (tumor or hemorrhage) causing abnormal changes in 1 or more component increase intracranial pressure
• the skull is not expandable

Question 7

1 st compliance for increased intracranial pressure

Answer 7

displace, reabsorb and decrease secretion of CSF

manipulate CSF first because blood flow to brain is important

Question 8

2nd compliance for increased intracranial pressure

Answer 8

venous compression and decrease perfusion (this is limited because causes ischemia and infarction, do not want infarction in the brain)

Question 9

final consequence for increased intracranial pressure

Answer 9

compression & displacement of the brain (death)

foreman magnum largest opening @ base of skull, worst scenario brain stem pushed through foreman magnum causing death

Question 10

Cushings reflex

Answer 10

late brain response to increased intracranial pressure

Question 11

what is cushings reflex triggered by

Answer 11

ischemia (in brain specifically vasomotor control center in brain stem)

Question 12

what is the formula for cerebral perfusion pressure

Answer 12

CPP=MAP-ICP

Question 13

what is cerebral perfusion pressure

Answer 13

cerebral perfusion pressure is not the blood pressure within brain, it is the pressure before the blood goes into cranium

Question 14

MAP =

Answer 14

mean arterial pressure

Question 15

brain is ischemic if cerebral perfusion pressure is

Answer 15

less then 40mmhg

Question 16

cushings triad is the brains response

Answer 16

to increased intracranial pressure -terminal stage

Question 17

the three things that make up cushings triad

Answer 17

• widening pulse pressure (pulse pressure= difference between systolic & diastolic ex. systolic moving up, diastolic dropping)
• reflexive bradycardia (HR drops)
• irregular breathing (change in breathing, no reason for irregular breathing)

Question 18

what is the formual for mean arterial pressure

Answer 18

SP + (2xDP)
_________
3