Monitoring Anesthetic Depth

Question 1

Conciousness is ____ and _____ activities

Answer 1

Cortical and subcortical activities

Question 2

Nociception is ______ activity

Answer 2

Subcortical activity

Question 3

Mobility is from

Answer 3

Spinal cord (ventral horn)

Question 4

When monitoring depth of anesthesia both ____ and ____ activities need to be assessed

Answer 4

Cortical and Subcortical

Question 5

When monitoring anesthesia depth consciousness is less important than

Answer 5

Subjective monitoring of subcortical activities/reflexes

Question 6

It takes _____ more anesthetic to inhibit movement than consciousness

Answer 6

3 times more

Question 7

What are the categories of subcortical signs

Answer 7

Brainstem activities Cranial nerve reflexes Spinal cord reflexes Autonomic nervous system activities/reflexes

Question 8

During neuromuscular blockade how can cortical activity be monitored

Answer 8

End tidal anesthetic % EEG or BIS monitor

Question 9

EEG gives information on ___ activities

Answer 9

Cortical but not subcortical

Question 10

EEG correlates with anesthetic depth but doesn’t predict ___

Answer 10

arousal or movement

Question 11

BIS monitor provides a number between

Answer 11

0 and 100

Question 12

BIS 0

Answer 12

Flat line EEG

Question 13

BIS 100

Answer 13

Fully awake

Question 14

BIS 40 - 60

Answer 14

Appropriate depth of anesthesia

Question 15

When and signs of Stage 1 of anesthesia

Answer 15

Voluntary Movement From drug administration to loss of consciousness Excitement/struggle Epi release, tachycardia, pupil dilation Irregular breathing Salivation, urination, defecation Ataxia, recumbency

Question 16

When and signs of Stage 2 of anesthesia

Answer 16

Involuntary Movement Loss of consciousness until the onset of regular breathing Delirium Exaggerated reaction to stimuli Strong palpebral Vomiting, regurg, salivation Strong jaw tone

Question 17

When and signs of Stage 3 of anesthesia

Answer 17

General Anesthesia Onset of regular breathing until the cessation of effective breathing No movement in response to noxious stimulation Has 3 planes Progressive muscle relaxation, loss of reflexes and resp depression

Question 18

Stage 3 Plane 1

Answer 18

Light anesthesia Nystagmus No swallowing reflex Pupils constrict Simple procedures/exams possible

Question 19

Stage 3 Plane 2

Answer 19

Medium anesthesia Progressive intercostal paralysis Stable resp and pulse Weak palp, strong corneal Adequate muscle relaxtion for most surgical procedures

Question 20

Stage 3 Plane 3

Answer 20

Deep anesthesia Abdominal breathing Pupils dilate No palpebral/corneal Some patients may have to be maintained at this stage but ideally should be at 2

Question 21

Stage 4

Answer 21

Overdose possible Cardiovascular adverse effects are possible even if isoflurane is not overdosed

Question 22

If hypotension is concerning during anesthesia

Answer 22

Anesthetic administration may have to be decreased regardless of current anesthetic depth

Question 23

Most surgeries and intubation are performed at

Answer 23

Stage 3 – Planes 2-3

Question 24

What is ketamine

Answer 24

Dissociated anesthetic Doesn’t supporess brain activity

Question 25

What may ketamine cause

Answer 25

Nystagmus, blinking, central eye position, dilated pupils at moderate depth

Question 26

What are the goals of anesthesia

Answer 26

Acceptable cardiovascular function Fully relaxed and immobile patient Least necessary anesthetic depth

Question 27

Central eye + dilated pupils may indicate

Answer 27

Too light or too deep anesthesia

Question 28

When might a nystagmus appear

Answer 28

Too light of anesthesia

With ketamine at appropriate depth

In horses at light but appropriate depth (a2 agonist CRI)

Question 29

When might spontaneous blinking occur

Answer 29

Too light of anesthesia

Slow blinking in horses (similar to nystagmus)

Question 30

When might you see lacrimation

Answer 30

Light but appropriate anesthetic depth especially in horses

Question 31

Palpebral/eyelash reflexes

Answer 31

Ideally a slow reflex but lack of can be acceptable

**Goal is not the lack of reflexes

Question 32

______ indicates overall muscle tone but it is individually variable

Answer 32

Jaw tone

Question 33

If spontaneous RR is high it may indicate

Answer 33

Too light anesthesia

or

Low lung volume

Question 34

Changing respiratory rate and pattern in response to surgical stimulus is a sign that

Answer 34

anesthesia may be light or analgesia insufficient

Question 35

Absolute HR ______ aid in determining anesthetic depth

Answer 35

DOESN’T aid in determing depth