Egar Video #10 Central Nervous System Effects of Inhaled Anesthetics

Question 1

With inhaled anesthesics, what happens to burst suppression over time?

Answer 1

burst suppression increases.

Normally increases at 1.25MAC.
EEG will be flat with burst supression.

Question 2

The awake person has cycles up to ___%

Answer 2

20

Question 3

Which anesthetic produce convulsions?

Answer 3

Sevoflurane and Enflurane

Question 4

What precipitates the convulsions?

Answer 4

1. Hypercarbia
2. Higher concentrations (I.e. greater than 2 MAC)
3. Pre-existing epileptic disorder

Question 5

Are the seizures produced by anesthetic dangerous per Egar?

Answer 5

No.

Whether they are connected ton post-op agitation is unclear.

Question 6

Risk of making crooked spinal cord straight?

Answer 6

Cord ischemia

Question 7

How do you know if cord ischemia has occured?

Answer 7

1. SSEPs - somatosensory evoke potentials
2. MEPs - motor evoke potentials

Question 8

What do potent anesthetics do to SSEPs?

Answer 8

they can effect the amplitude of latency of evoke potential.

as you increase anesthetics, the SSEPs decrease.

Note: nitrous oxide is not pictured!

Question 9

What difference does nitrous oxide had on SSEPs?

Answer 9

Nitrous oxide will cause more of a profound depression than sevo or iso.

Soooo, avoid giving pt nitrous oxide if they already have a problem with SSEPs.

Question 10

What do potent anesthetics do in brain?

Metabolism:
Cerebral Blood Flow:
Cerebral vascular resistance:
ICP:

Answer 10

Metabolism: decrease
Cerebral Blood Flow: decrease
Cerebral vascular resistance: increase
ICP: increase

Note: at concentrations of a MAC at 3/4 of a MAC there is not an increase or decrease.

NOTE: increase in CBF if the normal blood flow is maintained at normal levels.

Question 11

True or False:
Spinal anesthetics help protect patients against ischemic insults

Answer 11

True

*true with all potent inhaled anesthetics

Question 12

True of false:

Potent inhaled anesthetics are our friends to help protect brain against cerebral hypoxia.

Answer 12

True