Exam 2; General Anesthetics Flashcards Preview

AU14 Pharmacology > Exam 2; General Anesthetics > Flashcards

Flashcards in Exam 2; General Anesthetics Deck (34):
1

When should general anesthetics be used

only for surgery

2

What were two of the first general anesthetics used

ether
chloroform

3

What are the eight characteristics of the "ideal/balanced" anesthetic

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

4

What is the therapeutic index of general anesthetics

very low
the effective dose and lethal dose are VERY close together

5

What is the broad mechanism of action of general anesthetics

inhibition of neuronal firing

6

What two neurons do general anesthetics act upon

potentiation of inhibitory GABAnergic neurons
inhibition of excitatory glutaminergic neurons

7

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

cortex more sensitive than the brain

8

The higher the what, the more potent the agent

lipid solubility

9

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

MAC; minimal alveolar concentration
the lower the MAC the more potent the drug

10

The speed of induction is related to what

solubility of the agent in the blood

11

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

slower the onset (induction)

12

In general, the recovery from the general anesthetic is what

symmetrical with induction
rapid induction = rapid recovery

13

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

nitrous oxide

14

What is the MAC of nitrous oxide

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

15

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

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

16

Repeated exposure to nitrous oxide can cause what

megaloblastic leukemia and leukopenia

17

These are used to maintain anesthesia

the halogenated hydrocarbons; the "-fluranes"

18

What is a consequence of the "-fluranes"

increased incidence of liver disease with repeated exposure

19

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

malignante hyperthermia

20

What causes malignant hyperthermia due to the halogenated hydrocarbons

increased Ca uptake from skeletal muscle
increasing muscle metabolism; 42℃ --> 107℃

21

These have a more rapid onset than inhaled anesthetics

IV general anesthetics

22

This is a barbiturate IV-GA

methohexital

23

Methohexital binds to and activates what

GABAnergic neurons (inhibitory neuron)

24

Methohexital action is terminated by what

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

25

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

propofol

26

Propofol acts to do what

increase GABAnergic activity

27

Propofol has what effect

anti-emetic
lessens nausea

28

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

ketamine

29

ketamine has what kind of onset/duration

short induction/duration

30

What is the mechanism behind ketamine

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

31

Ketamine can cause what in patients emerging from anesthesia

hallucinations

32

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

etomidate

33

What is the mechanism of etomidate

activated GABA receptors

34

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

midazolam