Anesthetics and Local Anesthetics

Question 1

Anesthetic action is terminated how in general?

Answer 1

Redistribution from the site of anesthesia

Question 2

General anesthetics terminate how?

Answer 2

Leave brain

Question 3

Local anesthetics terminate how?

Answer 3

Leave site of action

Question 4

8 associated anesthesia effects

Answer 4

Relieve anxiety
Sedation
Prevent allergic response
Prevent aspiration of stomach contents or emesis
Analgesia
Prevent bradycardia 
Prevent pulmonary fluid secretions
Facilitation of incubation and relaxation

Question 5

Ideal anesthetic:
Timing of analgesia
Consciousness
Skeletal muscle
Reflexes
Memory
Safety

Answer 5

Analgesia that persists after procedure itself
Rapidly reversible depression of consciousness
Relaxation of skeletal muscle
Reduction in reflexes
Amnesia
Safety in operating room

Question 6

Is any drug perfect?

Answer 6

No

Question 7

What drug comes close to perfect?

What’s wrong?

Answer 7

Ether

Not safe for the operating room staff

Question 8

Four stages of anesthesia?
Which is target?
Which do you want to pass quickly?
Which do you want to avoid

Answer 8

Analgesia
Disinhibition: Pass through quickly
Surgical anesthesia: Target
Medullary depression: Avoid

Question 9

Disinhibition stage
Mental status
Reflex change
Respiration change
GI change

Answer 9

Delirium and excitation
Reflexes enhanced
Respiration irregular
Nausea and vomiting

Question 10

Surgical anesthesia:
Consciousness
Reflexes
Heart changes
Temperature change
Respiratory rate

Answer 10

Unconscious
No pain reflexes
Stable BP and rate
Temp stable
Normal respiratory rate

Question 11

How to get respiratory rate lower in surgical anesthesia safely

Answer 11

Oxygen supplementation

Question 12

2 severe aspects of medullary depression

Answer 12

Severe respiratory and CV depression

Question 13

3 parts of surgical anesthesia?

Answer 13

Induction
Maintenance
Recovery

Question 14

Goal of induction

Answer 14

Quick into anesthesia and to bypass disinhibition/excitatory phase

Question 15

Goal of maintenance

Answer 15

Maintain surgical anesthesia and vital functions

Question 16

Goal of recovery

Answer 16

Rapid emergence from anesthesia with short disinhibition

Question 17

Recovery is complete when the patient is? 3

Answer 17

Conscious
Alert
Responsive

Question 18

Two theories of how anesthetics work

Answer 18

Membrane expansion by 0.4% disrupts sodium channel function –> Decrease excitability

Anesthetic receptor that when activated interferes with sodium or chloride function.

Question 19

Most likely common anesthetic receptor target?

Answer 19

GABA

Question 20

Primary site of inhaled anesthetics

Answer 20

Brain/CNS

Question 21

Minimum Alveolar Concentration is what type of measurement?

Define

Answer 21

Dosage

Level needed to get 1/2 patients anesthetized in order to do a surgical incision 3 inches long in abdomen through all layers of muscle

Question 22

Rapid induction needs a MAC of what?

Answer 22

1.3/1.5

Question 23

Why is nitrous oxide never used solo?

Answer 23

MAC > 100.0

Question 24

Explain the relationship of solubility, induction and emergence and equilibrium.

Answer 24

Less soluble the gas –> Faster it reaches equilibrium –> Faster the induction and emergence

Question 25

Effect of inspired concentration on equilibrium

Answer 25

Higher the concentration --> Faster the equilibrium

Question 26

Deeper or faster inspiration effect on equilibrium?

Answer 26

Deeper or faster inspirations mean faster equilibrium

Question 27

Cardiac output effect on equilibrium

Answer 27

Faster CO --> Faster delivery

Question 28

What is the second gas effect?

Answer 28

Two gases put together actually gives a faster effect (increases concentration gradient)

Question 29

Why do you want a scavenger with a anesthetic apparatus?

Answer 29

Want what the patient is breathing out to not go into the surrounding room.

Question 30

What is an active scavenger?

Answer 30

Draws gas back out

Question 31

What is a passive scavenger?

Answer 31

Anesthetic is trapped in a chemical trap as patient breathes

Question 32

What happens when you turn off NO anesthetic?

Answer 32

NO rushes back into the alveolar space --> Displaces oxygen --> Diffusion hypoxia

Question 33

How to offset diffusion hypoxia? (2)

Answer 33

100% O2 administration | Maintaining normal ventilation

Question 34

Malignant hyperthermia is most common with what? | What is it related to?

Answer 34

Halogenated anesthetic or succinylcholine Increased myoplasmic calcium levels and increased coupling --> Leaving calcium causes contractions to continue

Question 35

How to treat malignant hyperthermia (3)

Answer 35

Withdraw drug Cool patient Treat with dantrolene

Question 36

``` Halothane 2 uses Effect on CV Effect on Respiratory Effect on SNS Effect on myocardium 1 toxic side effect ```

Answer 36

``` Uses: Weak analgesic + muscle relaxant CV: Depress Resp: Depress SNS: Block SNS reflexes Myocardium: More sensitive to catecholamines (arrhythmia) Toxicity: Hepato ```

Question 37

``` Enflurane Use: CV: SNS effect: Myocardium effect: Toxicity And why: Adverse effect Contraindication ```

Answer 37

``` Same as halothane CV depressant No SNS effect Sensitizes myocardium to catecholamines Renal Biotransformation product has fluoride Lowers seizure threshold Contraindicated in labor ```

Question 38

Isoflurane and Desflurane Respiratory effect CV effect: Myocardium effect

Answer 38

Resp: Stimulation of reflex and secretions CV: None Myocardium: None

Question 39

``` Desflurane Advantage: Reacts with what To form what: Causes what: How to alleviate ```

Answer 39

``` Ad: Fast induction sand rapid adjustments Dry absorbents Carbon monoxide Carboxyhemoglobinemia Use appropriate scavenger ```

Question 40

``` Nitrous Oxide MAC Use solo: Use overall: What effect to watch: Respiratory effect: CV effect ```

Answer 40

``` MAC: Over 100% Solo use: Do NOT Use overall: Analgesic Effect to watch: 2nd gas effect Resp: Potentiate depression of other drugs CV effect: Depressant ```

Question 41

Sevoflurane Who likes it the most: Induction/Emergence speed Adverse effect:

Answer 41

Kids like it the most --> Sweet scent Fast induction and emergence Adverse