clinical actions of specific agents

Question 1

most common causes of failure to achieve anesthesia

Answer 1

 Accuracy in deposition of local anesthesia (technique)
 Anatomical variation

Question 2

bell shaped curve of duration

Answer 2

 Normal responders ( 70%)
 Hyper-responders (15%)
 Hypo-responders (15%)

Question 3

do larger doses increase duration

Answer 3

no

Question 4

when should the maximum calculated dose decrease?

Answer 4

Maximum calculated drug dose should decrease in medically compromised, debilitated, or elderly persons

Question 5

 What if I exceed MRD accidentally, does patient automatically OD?

Answer 5

 NO, when exceeding MRD, there is a greater likelihood of OD arising
• In fact OD may arise at the dosage below the calculated MRD (hyper-responders)

Question 6

 How to determine doses, if two drugs are used?

Answer 6

 The total dose of both local anesthetics not exceed the lower of the two
maximum doses for the individual agent.

Question 7

Lidocaine
 Potency:
 Metabolism locatin
 Onset of action:
 Anesthetic t ½ :

Answer 7

 Potency: the standard
 Metabolism: liver
 Onset of action: rapid (2-3 mins)
 Anesthetic t ½ : 1.6 hours

Question 8

lidocaine MRD
mg/kg
absolute max
cartridges

Answer 8

 4.4mg/kg
 Absolute maximum 300mg
 8 Cartridges will be the maximum # used on a patient

Question 9

max epi in healthy vs unhealthy pt

Answer 9

 Healthy patient, maximum epinephrine is 0.2mg or 200mcg
 Cardio patient, maximum epinephrine is 0.04mg or 40mcg

Question 10

how should lido MRD be concluded between epi/lido?

Answer 10

 Maximum dose is limited to
• First: maximum amount of epinephrine can be given
• Second: lowest possible dosage of lidocaine needed

Question 11

lido replaced?

Answer 11

procaine, faster onset for lido

Question 12

can you be allergic to lido?

Answer 12

Allergy to amide is virtually nonexist

Question 13

gold standard LA?

Answer 13

lido

Question 14

Mepivacaine
Potency:
Metabolism site:
Onset of action:
Anesthetic t ½ :

Answer 14

Mepivacaine
Potency: similar to lidocaine
Metabolism: Liver
Onset of action: Rapid (1.5 to 2 mins)
Anesthetic t ½ : 1.9 hours

Question 15

mepivacaine Maximum Recommended Dose ( MRD):
mg/kg
absolute max
cartridges

Answer 15

:
 4.4mg/kg
 Absolute maximum 300mg
 5.5 cartridges will be maximum # used on a patient

Question 16

mepivacaine vascular effect

Answer 16

mild dialation

Question 17

mepivacaine duration compared to others without constrictor

Answer 17

longer

Question 18

 3% Mepivacaine plain provides
pulpal/ soft tissue anesthesia

Answer 18

 20-40 mins pulpal anesthesia
 2-3 hours soft tissue anesthesia

Question 19

mepivacaine indications

Answer 19

 When vasoconstrictor is NOT indicated
 Most often used in pediatric / geriatric patient

Question 20

Prilocaine
 Potency:
 Metabolism/possible effect?
 Onset of Action:
 Anesthetic t ½ :

Answer 20

 Potency: similar to Lidocaine
 Metabolism: Hydrolyzed to orthotoluidine and N-propylalanine
 Orthotoluidine induce methemoglobin
• May cause observable cyanosis
 Onset of Action: slightly slower (2-4 mins)
 Anesthetic t ½ : 1.6 hours

Question 21

Prilocaine Maximum Recommend Dose:
mg/kg
absolute max
cartridges

Answer 21

 6.0mg/kg
 Absolute Maximum 400mg
 5.5 cartridges will be the maximum # used on a patient

Question 22

Prilocaine Relatively contraindicated in:
Hb?
RBC?
cardio/res?
drug?

Answer 22

 Idiopathic / congenital methemoglobinemia
 Hemoglobinopathies (Sickle cell anemia)
 Anemia
 Cardiac / Respiratory failure evidenced by hypoxia
 Patient taking Acetaminophen or Phenacetin- Produce elevations in methemoglobin level

Question 23

Bupivacaine
 Potency:
 Metabolism site:
 Onset of Action:
 Anesthetic t ½ :

Answer 23

 Potency: 4X lidocaine
 Metabolism: Liver
 Onset of Action: Longer 6-10 mins or occasionally similar to lidocaine
 Anesthetic t ½ : 2.7 hours (Long Duration)

Question 24

bupivacaine Maximum Recommended Dose:
mg/kg
absolute mg
cartridges?

Answer 24

Maximum Recommended Dose:
 1.3mg/kg
 Absolute maximum 90 mg
 10 cartridges is the maximum # used on a patient

Question 25

bupivacaine Primary indication

Answer 25

 Lengthy dental procedure >90 mins pulpal anesthesia is needed
 Management of postoperative pain- Reduce post-op opioid analgesics

Question 26

bupivacaine not recommended on

Answer 26

 Younger patient
 Physically / mentally disabled person

Question 27

phases of effective pain management

Answer 27

pre op
peri op
post op

Question 28

pre op pain management

Answer 28

 pretreatment of 1 or 2 doses of NSAID

Question 29

peri op pain management

Answer 29

 Local anesthesia
 Long-duration local anesthesia given upon D/C

Question 30

post-op pain management

Answer 30

 Continue oral NSAID q X hours for Y days

Question 31

Articaine
Potency:
Metabolism:
Onset of Action:
Anesthetic t ½ :

Answer 31

Potency: 1.5X lidocaine
Metabolism:
 Only amide type L.A. with ester group
• Plasma esterase hydrolysis
• Liver metabolism mainly
Onset of Action:1-2 mins infiltration
Anesthetic t ½ : 0.5 hours

Question 32

Articaine Maximum Recommended Dose:

Answer 32

Maximum Recommended Dose:
 7mg/kg

Question 33

Articaine Contraindications:
allergies to?
sensitive to?
caution with what dx?
cardio?
children?

Answer 33

 Patient allergic to amide type anesthesia (few to none)
 Sulfite sensitivity
 Caution with hepatic disease
 Patient with significant impairments in cardiovascular function
 Children < 4 y/o is not recommended due to insufficient data

Question 34

down side of articaine

Answer 34

analog to prilocaine
Prior to introduction of articaine, prilocaine accounted for 51% of paresthesias in the US, while being used for 13 % of injections
Indicates potential for neuro-toxicity of articaine and prilocaine

Question 35

Is 4% articaine too concentrated?

Answer 35

Is 4% too concentrated?
Animal studies show increased
neurological deficits with 4%
lidocaine
Human studies show the same
with 5% lidocaine

Question 36

closet to ideal anesthetic

Answer 36

2% lidocaine with 1:100,000
epinephrine is still the closest to
the ideal intermediate-duration
local anesthetic in dentistry.

Question 37

Topical anesthesia is effective only on?
 This is sufficient to allow?

Answer 37

Topical anesthesia is effective only on
surface tissue (2-3mm)
 This is sufficient to allow atraumatic needle
penetration

Question 38

Benzocaine
chemical structure?
cardio absorbtion?
injection?
allergies?
most commonly used as?

Answer 38

Benzocaine
Ester local anesthesia
Poor absorption into cardiovascular system
Not suitable for injection
Ester local anesthesia are more allergenic than amide
Most commonly used topical anesthesia

Question 39

Lidocaine (Topical) forms

Answer 39

 Two forms

 Lidocaine base- Poorly soluble in H2O

 Lidocaine hydrochloride
• Water soluble
• Better tissue penetration but systemic absorption is also greater

Question 40

 Maximum recommend dose of topical lidocaine

Answer 40

 Maximum recommend dose is 200mg
 Keep in mind for the “other” injection lidocaine !!!

Question 41

2% lido with 1:100000 epi pulpal/soft tissue length

Answer 41

pulp:1h
soft: 3-5h

Question 42

3% mepivicane pulpal/soft tissue length?

Answer 42

pulp:5-10min
soft: 1.5h

Question 43

0.5% Bupivacaine +Epi
1:200,000 pulp/soft tissue length?

Answer 43

pulp: >1h
soft: 4-12 (h)

Question 44

Articaine 4% + epi 1:100,000 pulp/soft length

Answer 44

pulp: 0.5(h)
soft: 3-5 (h)