Monday, 8-22-Local Anesthetics-DSA-Kruse

Question 1

What chemical class are benzocaine, cocaine, procaine, and tetracaine part of?

Answer 1

Esters

Question 2

__ local anesthetics are widely distributed after IV bolus administration, while tissue distribution of __ type agents have not been extensively evaluated d/t their extremely short plasma 1/2 lives

Answer 2

Amide

Ester

Question 3

___ agents are metabolized in the plasma while ___ types are metabolized in the liver and then excreted in the urine as charged substances

Answer 3

Ester type

Amide

Question 4

___ compounds are hydrolyzed by circulating butyrylcholinesterase enzymes (plasma cholinesterase)

Answer 4

Ester type

Question 5

__ are hydrolyzed by liver CYP 450 enzymes and toxicity from these type of anesthetics are more likely to occur in pts with hepatic disease

Answer 5

Amide linkage of amide-type agents

Question 6

Local anesthetics block __ channel currents and stop the spread of APs across the nerve axons

Answer 6

Voltage-gated Na

Receptor site for local anesthetics is at the inner vestibule of the Na channel

Question 7

the ___ the local anesthetic, the faster the rate of interaction with the Na channel and the more potent the agents actions

Answer 7

Smaller and more lipophilic

Question 8

These drugs are more lipophilic than lidocaine, procaine, and mepivacaine and are therefore more potent and have longer durations of action

Answer 8

Tetracaine, bupivacaine, and ropivacaine

Question 9

Local anesthetics preferentially block __ fibers because the distance over which such fibers can passively propagate an electrical impulse is shorter

Answer 9

Small fibers

Question 10

What type of fiber is more likely to become blocked first: a preganglionic B fiber or a smaller unmyelinated C fiber?

Answer 10

Preganglionic B fibers

Myelinated nerves tend to become blocked before unmyelinated nerves of the same diameter

Question 11

Which fibers will likely be blocked earlier: large A alpha fibers or type A delta and C fibers?

Answer 11

Type A delta and C fibers are blocked earlier than the large A alpha fibers

Fibers that fire at higher frequencies of depolarization are blocked before those that fire slower

Question 12

__ anesthesia is injection of local anesthetic directly into tissue in the vicinity of peripheral nerve endings without taking into consideration the course of cutaneous nerves.

Answer 12

Infiltration

Can be superficial enough to include only the skin and deep enough to include intraabdominal organs

Question 13

___ anesthesia is in injections of local anesthetics in major nerve trunks and the purpose is to anesthetize a region distal to the site of injection

Answer 13

Block

Femoral n block for surgery distal to the knee, brachial plexus block for procedures on UE’s or shoulders

Question 14

__ anesthesia is injection of local anesthetic into the CSF in the lumbar space

Answer 14

Spinal

Produces anesthesia over a considerable fraction of the body with a dose of local anesthetic that produces negligible plasma levels

Question 15

__ anesthesia can be performed in the sacral hiatus or in the L, T, or C regions of the spine

Answer 15

Epidural

Injection of a local anesthetic into the epidural space

Question 16

__ anesthesia can be used for short surgical procedures (

Answer 16

IV regional

Question 17

Coadministration of local anesthetics and __ decrease the rate of anesthetic absorption into circulation, reduces the rate at which the local anesthetic is metabolized, and reduces systemic toxicity

Answer 17

Vasoconstrictors

Question 18

___ containing solutions should not be injected into tissues supplied by end arteries (fingers, toes, nose, ears, penis) because resulting vasoconstriction may cause gangrene

Answer 18

Epinephrine

Question 19

When large doses of a local anesthetic are required, premedication with __ can provide prophylaxis against CNS toxicity by raising the seizure threshold

Answer 19

Parenteral benzodiazepine (diazepam or midazolam)

Question 20

___ may be the most cardiotoxic due to its long durations of action

Answer 20

Bupivacaine

Question 21

__ is a Class Ib antiarrhythmic by suppressing automaticity of conduction tissue by increasing electrical stimulation thresholds of ventricles, His-purkinje system, and spontaneous depolarization of the ventricles during diastole by a direct action on the tissues

Answer 21

Lidocaine

Question 22

The most common adverse effect of IV lidocaine is __ toxicity, which is typically mild, dose-dependent, and always resolves upon discontinuation

Answer 22

CNS

Question 23

Allergic rxns to __ local anesthetics are most common due to metabolism to allergy-causing compounds

Answer 23

Ester type

Allergies to amide-type local anesthetics are extremely rare)

Pts who are allergic to 1 ester-type agent will most likely be allergic to another ester-type agent

Question 24

___ has poor solubility in water, used only as a topical agent. It can be used topically for dermatologic conditions, hemorrhoids, premature ejaculation, and as an anesthetic lubricant (NG and endocopic tubes and catheters)

Answer 24

Benzocaine

Question 25

__ is an agent with long DOA capable of producing prolonged anesthesia. It has a tendency to provide more sensory block than motor block

Answer 25

Bupivacaine

Question 26

The clinically desired properties of __ are the blockade of nerve impulses and local vasoconstricting actions secondary to its ability to inhibit local NE reuptake. Its euphoric properties are primarily due to inhibition of catecholamine reuptake (mainly dopamine in CNS). It is used primarily as a topical anesthetic in the UR tract

Answer 26

Cocaine

Question 27

__ is now used only as a topical cream for use on the skin d/t toxicity associated with injections

Answer 27

Dibucaine

Question 28

___ produces faster, more intense, longer lasting, and more extensive anesthesia than an equal dose of procaine. It is a prototypical amide local anesthetic and an alternative choice for pts with sensitivity to ester-type local anesthetics. It can be used as an antiarrhythmic agent

Answer 28

Lidocaine

Question 29

Compared to newer agents, __ generally has lower potency, slower onset, and shorter DOA. It is only used for infiltration anesthesia and metabolized to a para-aminobenzoid acid, which inhibits the action of sulfonamide abx

Answer 29

Procaine

Question 30

What chemical class are lidocaine, mepivacaine, bupivacaine, ropivacaine, and articaine part of?

Answer 30

Amides