Chapter 29 - Local Anaesthetics

Question 1

Lidocaine is an _______

Answer 1

amide

Question 2

Procaine is an _______

Answer 2

ester

Question 3

How do local anaesthetics act?

Answer 3

suppress pain by blocking sodium channels and impulse conduction along axons

Question 4

Where do local anaesthetics act?

Answer 4

-near administration site
-suppress pain without depression of nervous system

Question 5

What is the onset of local anaesthesia?

Answer 5

2-15 mins

Question 6

What determines the ability of an anaesthetic to penetrate the axon membrane?

Answer 6

-size of molecule
-lipid solubility
-degree of ionization at tissue pH

Question 7

How does epinephrine act as a vasoconstrictor?

Answer 7

-decreases local blood flow
-delay systemic anaesthetic absorption (prolong anaesthesia)
-reduces toxicity risk

Question 8

What can absorption of epi cause?

Answer 8

-palpitations
-tachycardia
-nervousness
-hypertension

Question 9

What is the role of epi in local anaesthesia?

Answer 9

used along side a local anaesthetic

Question 10

What are the adverse effects of local anaesthetics?

Answer 10

-CNS excitation followed by depression
-bradycardia
-heart block
-reduced contractile force
-cardia arrest
-hypotension
-allergic reaction (ester type anaesthetic)
-prolong labour

Question 11

Do not use topical benzocaine in children younger than ____

Answer 11

2

Question 12

Is procaine ester or not?

Answer 12

ester

Question 13

What is the most widely used local anaesthetic?

Answer 13

lidocaine

Question 14

How is lidocaine administered?

Answer 14

-ointment
-jelly
-solution
-patch
-spray
-injection

Question 15

How do epinephrine and lidocaine interact?

Answer 15

epi extends lidocaine effects

Question 16

What is another use of lidocaine?

Answer 16

cardiac dysrhytmias

Question 17

What are the topical local anaesthetics?

Answer 17

lidocaine, tetracaine, and cocaine

Question 18

Topical local anaesthetics can cause ___________ _________

Answer 18

systemic toxicity

Question 19

What are rules for topical local anaesthetics?

Answer 19

-apply smallest amount
-don’t apply to large areas
-don’t apply to broken or irritated skin
-avoid strenuous exercise, wrapping site, heating site

Question 20

How is tetracaine administered?

Answer 20

opthalmic drops

Question 21

What are topical local anaesthetics used for?

Answer 21

-pain relief
-itching
-soreness from burns and bites
-mucous membrane issues
-hemorrhoids
-anal fissures

Question 22

Injectable local anaesthetics are administered by…

Answer 22

anesthesiologist

Question 23

safety for injectable local anaesthetics:

Answer 23

-resuscitation equipment available
-IV for rapid toxicity tx
-ASPIRIATE before injection

Question 24

What needs to be monitored for injected local anaesthetic?

Answer 24

-CV status
-resp. function
-consciousness

Question 25

Infiltation

Answer 25

injecting a local anaesthetic directly into the immediate area of surgery or manipulation

Question 26

Nerve Block

Answer 26

injecting a local anaesthetic into or near nerves that supply surgical area but at a distant site

Question 27

IV regional

Answer 27

employed to anesthetize the extremities but not entire limb

Question 28

Epidural

Answer 28

local anaesthetic injection into epidural space

Question 29

Spinal (subarachnoid)

Answer 29

injecting local anaesthetic into the subarachnoid space

Question 30

What drugs are used for eipdural?

Answer 30

lidocaine and bupivacaine

Question 31

What drugs are used for spinal anaesthetic?

Answer 31

-bupivacaine
-lidocaine
-tetracaine

Question 32

What are the adverse effects of injected anaesthetics?

Answer 32

-hypotension
-fecal and urinary incontinence
-urinary retention
-spinal headaches
-bradycardia
-heart block
-cardiac arrest