Exam 2; General Anesthetics

Question 1

When should general anesthetics be used

Answer 1

only for surgery

Question 2

What were two of the first general anesthetics used

Answer 2

ether

chloroform

Question 3

What are the eight characteristics of the “ideal/balanced” anesthetic

Answer 3

loss of consciousness
amnesia; don't want to remember
analgesia
inhibition of reflex
muscle relaxation
rapid onset of and recovery from anesthesia
pleasant experience
no dangerous side effects

Question 4

What is the therapeutic index of general anesthetics

Answer 4

very low

the effective dose and lethal dose are VERY close together

Question 5

What is the broad mechanism of action of general anesthetics

Answer 5

inhibition of neuronal firing

Question 6

What two neurons do general anesthetics act upon

Answer 6

potentiation of inhibitory GABAnergic neurons

inhibition of excitatory glutaminergic neurons

Question 7

Which portion of the brain is more sensitive, the cortex or the thalamus

Answer 7

cortex more sensitive than the brain

Question 8

The higher the what, the more potent the agent

Answer 8

lipid solubility

Question 9

The concentration at 50% (ED50) of patients unresponsive is what, which describes potency

Answer 9

MAC; minimal alveolar concentration

the lower the MAC the more potent the drug

Question 10

The speed of induction is related to what

Answer 10

solubility of the agent in the blood

Question 11

The more soluble the agent is in the blood (high blood/gas coefficient), the what

Answer 11

slower the onset (induction)

Question 12

In general, the recovery from the general anesthetic is what

Answer 12

symmetrical with induction

rapid induction = rapid recovery

Question 13

This is a gas at room temperature and is insoluble in blood; rapid onset = rapid recovery, low amnesia, low potency

Answer 13

nitrous oxide

Question 14

What is the MAC of nitrous oxide

Answer 14

> 100%

not very effective (need to berate more than 100% concentration of air as NO; which is not plausible

Question 15

Because nitrous oxide is not soluble in the blood, what tends to happen to the patient

Answer 15

the NO leads the blood and enters the body cavity as gas; causing discomfort

Question 16

Repeated exposure to nitrous oxide can cause what

Answer 16

megaloblastic leukemia and leukopenia

Question 17

These are used to maintain anesthesia

Answer 17

the halogenated hydrocarbons; the “-fluranes”

Question 18

What is a consequence of the “-fluranes”

Answer 18

increased incidence of liver disease with repeated exposure

Question 19

This is a major consequence of halogenated hydrocarbons resulting from a genetic defect

Answer 19

malignante hyperthermia

Question 20

What causes malignant hyperthermia due to the halogenated hydrocarbons

Answer 20

increased Ca uptake from skeletal muscle

increasing muscle metabolism; 42℃ –> 107℃

Question 21

These have a more rapid onset than inhaled anesthetics

Answer 21

IV general anesthetics

Question 22

This is a barbiturate IV-GA

Answer 22

methohexital

Question 23

Methohexital binds to and activates what

Answer 23

GABAnergic neurons (inhibitory neuron)

Question 24

Methohexital action is terminated by what

Answer 24

redistribution in from the brain; the minute the concentration decreases, it stops

Question 25

This is the most commonly used parental anesthetic with a rapid onset and short duration

Answer 25

propofol

Question 26

Propofol acts to do what

Answer 26

increase GABAnergic activity

Question 27

Propofol has what effect

Answer 27

anti-emetic

lessens nausea

Question 28

This is an analog of phencyclidine which causes “dissociative anesthesia” - profound amnesia and analgesia

Answer 28

ketamine

Question 29

ketamine has what kind of onset/duration

Answer 29

short induction/duration

Question 30

What is the mechanism behind ketamine

Answer 30

bind to a receptor which inhibits glutamate neurons (activating neurons)

Question 31

Ketamine can cause what in patients emerging from anesthesia

Answer 31

hallucinations

Question 32

This is a very rapid, non-analgesic with a high therapeutic index (conscious sedation), causes some post-op nausea

Answer 32

etomidate

Question 33

What is the mechanism of etomidate

Answer 33

activated GABA receptors

Question 34

This is a benzodiazepine which binds to benzodiazepine receptors and enhances GABAnergic activity; causes amnesia

Answer 34

midazolam