Intro to Neuro Anesthesia PPT Flashcards Preview

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Flashcards in Intro to Neuro Anesthesia PPT Deck (39)
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1

How much does the adult brain weigh?

1350gm (2% of tbw)

2

What is CBF? (flow)

45-55 ml/100g/min

3

How do you calculate CBF?

CBF= CPP/CVR

4

How much of your cardiac output goes to the brain?

12-15%

5

what is the CMRO2 of the brain?

3/5ml/100g/min (20% of total O2 consumption)

6

How do you calculate CPP?

CPP=MAP-ICP

7

What is CVR? (flow)

1.5-2.1 mmHg/100g/min/ml

8

How do changes in the CBF change CMRO2?

They are directly coupled.

9

What happens to CMRO2 when you sleep?

it decreases

10

For every 1 degree celsius decrease in body temp below 37 how is CBF effected?

decreases 7%

11

How do volatile anesthetics effect CMRO2?

reduces it

12

Rank different induction medications in order of decreasing CMRO2....

thiopental>etomidate>propofol

13

What MAP is required to maintain CBF?

70-150

14

What is the Myogenic Hypothesis?

transient changes in CBF (3-4 min) due to rapid changes in MAP. Most likely due to direct changes in the tone of the vascular smooth muscle.

15

Neurogenic innervation includes

cholinergic, adrenergic, serotonin, and vasoactive intestinal peptide.

16

Neurogenic influence is greatest on?

large cerebral arteries.

17

How does HCT and viscosity effect CBF?

decreases CBF when HCT is >55%

18

What type of pt are we concerned with high HCT?

smokers

19

In case you didn't do my Nag questions....
what is an astrocyte?

support, metabolic function, nutritive functions

20

ependymal cells

lines cavities of the CNS and makes up the walls of the ventricles

21

microglia cells

phagocytosis

22

oligodendrocytes

insulation for axons- myelin sheath in brain and spinal cord

23

schwann cells

insulation- myelin sheath in peripheral nervous system

24

Tell me about the BBB

effective isolation for the brain and spinal cord, tight junctions between cells.

25

What portions of the brain are exempt from the BBB?

area postrema, pituitary gland, pineal gland, choroid plexus, and parts of the the hypothalamus

26

VAAs and increased CBF rank em

halothane>>enflurane>desflurane=idoflurane>sevoflurane

27

How does N2O effect the brain?

increases CBF, ICP, and CMRo2

28

How does Ketamine effect PaCO2, CBF and ICP without controlled ventilation?

increased!!!!

29

How do you minimize the effects of ketamine?

give it with another sedative or anesthetics and with controlled ventilation

30

What do benzos and barbs do to CMRO2 and CBF?

reduce them in a dose dependent fashion