L15 CSF, ICP, CBF

Question 1

how much CSF in the ventricles?

Answer 1

30 mL

Question 2

what’s the typical pressure gradient from CSF to sinuses?

Answer 2

5-7 mmHg

9-12 mmH2O

Question 3

how much is cerebral blood flow?

Answer 3

55 mL/min/100 g brain

750 mL/min

Question 4

at which CBF does brain ischemia occur?

Answer 4

18-20 mL/min/100g brain

Question 5

at which CBF does brain neuronal cell death occur

Answer 5

8-10 mL/min/100g brain

Question 6

formula for cerebral perfusion pressure (CPP)?

Answer 6

CPP = MAP - ICP

Question 7

formula for cerebral blood flow (CBF)?

Answer 7

CBF = CPP/CVR

Question 8

what term is used to describe hydrocephalus with impaired reabsorption?

Answer 8

communicating

Question 9

what term is used to describe hydrocephalus with blockage?

Answer 9

non communicating

Question 10

what drug can decrease CSF production?

Answer 10

carbonic anhydrase inhibitor (acetazolamide)

Question 11

how to lower ICP?

Answer 11

decrease CSF
decrease CBV
relieve mass effect

Question 12

how to decrease CSF?

Answer 12

external ventricular drain
decrease CSF production
decrease brain interstitial fluid

Question 13

how to decrease CBV?

Answer 13

normalize pCO2 and pO2
maximize venous outflow
hyperventilate to decrease pCO2
increase CPP (increase MAP to paradoxically lower ICP)