Anesthetics - Dr. Tomas

Question 1

Anesthetics have ____ therapeutic index.

Answer 1

narrow

Question 2

Anesthesia decreases arterial BP by:
A. Vasodilation
B. Myocardial depression
C. Blunted baroreceptor control so the body can’t determine what the appropriate BP should be
D. General decrease in sympathetic control
E. All of the above

Answer 2

E. All of the above

Question 3

True or False: Anesthesia requires airway maintenance because it reduces or eliminates both ventilatory drive and respiratory reflexes designed to maintain the airway.

Answer 3

True

Question 4

True or False: If there is a blockage/obstruction of the airway under anesthesia, your body can gag/cough it up like normal to get rid of the blockage.

Answer 4

False! Normal respiratory reflexes like that are reduced/eliminated while under anesthesia.

Question 5

Which of the following respiratory effects of anesthesia can cause you to regurgitate and may lead to aspiration?
A. Reduction/elimination of ventilatory drive
B. Reduction/elimination of respiratory reflexes
C. Lower esophageal sphincter tone reduction
D. A and B

Answer 5

C. Lower esophageal sphincter tone reduction

Question 6

Hypothermia is a physiological effect of anesthesia. It is defined as a body temperature less than ___°C.

Answer 6

< 36°C

Question 7

List the 4 main physiological effects to consider with general anesthesia.

Answer 7

1. Hemodynamic effects
2. Respiratory effects
3. Hypothermia
4. Nausea & vomiting

Question 8

General anesthetics act on the Chemoreceptor Trigger Zone (CTZ) and _____ (the “vomiting center” in brainstem).

Answer 8

Area Postrema

Question 9

The use of ____ to induce anesthesia may help to overcome the N/V aspect of anesthetics.

Answer 9

Propofol

Question 10

______ is the global but reversible depression of CNS functioning resulting in the loss of response to, and perception of all external stimuli.

Answer 10

General anesthesia

Question 11

What are the 5 components of anesthesia that are absolutely necessary for them to work well.

Answer 11

1) Amnesia
2) Immobility
3) Attenuation of autonomic responses
4) Analgesia
5) Unconsciousness

Question 12

The ____ is measured by determining [drug] that prevents movement in response to surgical stimulation.

Answer 12

Anesthetic potency

Question 13

The anesthetic potency of inhaled anesthetics is measured in MAC units
(Minimum Alveolar Concentration), which is the percentage of inhaled gas that is anesthetic. Which of the following is true?
A. High MAC means high potency
B. High MAC means low potency
C. Low MAC means low potency
D. MAC is not related to potency

Answer 13

B. High MAC means low potency (and low MAC means high potency)

Question 14

Though the mechanism of action of general aesthetics is widely unknown, the immobilization element of inhaled anesthetics occurs by acting at the _________.

Answer 14

Spinal cord

Question 15

True or False: Inhaled and IV anesthetics depress excitability of thalamic neurons, which plays a role in the sedative effects of these agents.

Answer 15

False! Only Inhaled works on the thalamus.

Question 16

True or False: Inhaled and IV anesthetics depress hippocampal neurotransmission, which plays a role in the amnesic effects of general anesthetics.

Answer 16

True

Question 17

_____ anesthetics hyperpolarize neurons, which decreases likelihood of neuron depolarization.
A. IV
B. Inhalational
C. IV and inhalational

Answer 17

B. Inhalational

Question 18

At anesthetizing concentrations, _______ anesthetics have substantial effects on synaptic transmission and smaller effects on action potential generation and propagation.
A. IV
B. Inhalational
C. IV and inhalational

Answer 18

C. IV and inhalational

Question 19

______ anesthetics inhibit excitatory synapses and enhance inhibitor synapses via effects on pre- and post-synaptic sites.
A. IV
B. Inhalational
C. IV and inhalational

Answer 19

B. Inhalational

Question 20

_____ anesthetics have a more narrow range of effects, usually work at synapse and primarily on post-synaptic sites, and most predominantly act by enhancing inhibitory neurotransmission (by enhancing GABAergic neurotransmission.
A. IV
B. Inhalational
C. IV and inhalational

Answer 20

A. IV

Question 21

Ketamine is an IV anesthetic but works differently than other IV anesthetics in terms of their cellular mechanism. How does ketamine work?

Answer 21

Predominantly inhibit excitatory neurotransmission at glutamatergic synapses rather than working like other IV anesthetics by enhancing GABAergic neurotransmission.

Question 22

The only general anesthetics that do not have significant effects on GABA-A or glycine receptors, but DO have effect on NMDA receptors of glutamate, are _______.

Answer 22

Ketamine and nitrous oxide

Question 23

We know that inhalational anesthetics enhance glycine’s ability to activate glycine receptors (glycine is inhibitory). Which IV anesthetics do so as well?

Answer 23

Barbiturates and propofol

Question 24

Agents that work on GABA-A to promote chloride conductance include most inhalationals as well as _____.

Answer 24

Propofol and etomidate

Question 25

Two-pore Domain Channels are K+ channels that set resting membrane potential in neurons. Anesthetics that act here are ____.

Answer 25

halogenated anesthetics

Question 26

A vesicular protein called synaptobrevin will interact with specific proteins on the nerve terminal, called _____ and SNAP-25), so that these vesicles can fuse with the presynaptic membrane and release their contents once calcium comes in.

Answer 26

Syntaxin-1

Question 27

Partition coefficients = ratio of concentrations in two tissues. Common partition coefficients for gases (inhalational anesthetics) are blood:gas, brain:blood, fat:blood. A higher Blood:Gas ratio means (more OR less) soluble in blood than air.

Answer 27

More soluble in blood than air

Question 28

Low tissue solubility means a (more rapid OR slower) recovery from anesthetics.

Answer 28

More rapid

Question 29

High tissue solubility means a (more rapid OR slower) recovery from anesthetics.

Answer 29

slower

Question 30

Local anesthetics bind to (activated OR inactivated) sodium channels.

Answer 30

Inactivated (because we want them to stay inactivated for a while to inhibit generation of action potential).

Question 31

True or False: Selectivity of effects of local anesthetics on Na+ channels is concentration dependent.

Answer 31

True

Question 32

In terms of local anesthetic action, small diameter axons are (more OR less) susceptible than larger diameter axons.

Answer 32

More

Question 33

In terms of local anesthetic action, myelinated axons are (more OR less) susceptible than unmyelinated axons.

Answer 33

More

Question 34

In local anesthetics, duration of action is (directly OR inversely) related to regional blood flow.

Answer 34

Inversely (So greater blood flow = greater dissipation of the anesthetic from the area of effect)

Question 35

_______ can be included with the local anesthetic when administering to the patient to slow the absorption rate.

Answer 35

Epinephrine (bc it vasoconstricts)

Question 36

Which local anesthetic has unique vasoconstricting effects within itself, so it doesn't have to be administered with epinephrine?

Answer 36

Cocaine

Question 37

In terms of local anesthetic action, potency and duration of action are (directly OR inversely) proportional to hydrophobicity.

Answer 37

Directly proportional (moderate is best)

Question 38

Which of the following factors influence local anesthetic absorption and distribution? A. Dosage B. Epinephrine present C. Injection site D. Chemical properties (whether it's hydrophobic or not) E. All of the above

Answer 38

E. All of the above

Question 39

Which of the following is not a desired characteristic of anesthesia? A. Rapid and pleasant induction of surgical anesthesia B. Absence of secondary effects C. Low therapeutic index D. Sufficient skeletal muscle relaxation

Answer 39

C. Low therapeutic index