clinical actions of specific agents Flashcards
most common causes of failure to achieve anesthesia
Accuracy in deposition of local anesthesia (technique)
Anatomical variation
bell shaped curve of duration
Normal responders ( 70%)
Hyper-responders (15%)
Hypo-responders (15%)
do larger doses increase duration
no
when should the maximum calculated dose decrease?
Maximum calculated drug dose should decrease in medically compromised, debilitated, or elderly persons
What if I exceed MRD accidentally, does patient automatically OD?
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)
How to determine doses, if two drugs are used?
The total dose of both local anesthetics not exceed the lower of the two
maximum doses for the individual agent.
Lidocaine
Potency:
Metabolism locatin
Onset of action:
Anesthetic t ½ :
Potency: the standard
Metabolism: liver
Onset of action: rapid (2-3 mins)
Anesthetic t ½ : 1.6 hours
lidocaine MRD
mg/kg
absolute max
cartridges
4.4mg/kg
Absolute maximum 300mg
8 Cartridges will be the maximum # used on a patient
max epi in healthy vs unhealthy pt
Healthy patient, maximum epinephrine is 0.2mg or 200mcg
Cardio patient, maximum epinephrine is 0.04mg or 40mcg
how should lido MRD be concluded between epi/lido?
Maximum dose is limited to
• First: maximum amount of epinephrine can be given
• Second: lowest possible dosage of lidocaine needed
lido replaced?
procaine, faster onset for lido
can you be allergic to lido?
Allergy to amide is virtually nonexist
gold standard LA?
lido
Mepivacaine
Potency:
Metabolism site:
Onset of action:
Anesthetic t ½ :
Mepivacaine
Potency: similar to lidocaine
Metabolism: Liver
Onset of action: Rapid (1.5 to 2 mins)
Anesthetic t ½ : 1.9 hours
mepivacaine Maximum Recommended Dose ( MRD):
mg/kg
absolute max
cartridges
:
4.4mg/kg
Absolute maximum 300mg
5.5 cartridges will be maximum # used on a patient
mepivacaine vascular effect
mild dialation
mepivacaine duration compared to others without constrictor
longer
3% Mepivacaine plain provides
pulpal/ soft tissue anesthesia
20-40 mins pulpal anesthesia
2-3 hours soft tissue anesthesia
mepivacaine indications
When vasoconstrictor is NOT indicated
Most often used in pediatric / geriatric patient
Prilocaine
Potency:
Metabolism/possible effect?
Onset of Action:
Anesthetic t ½ :
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
Prilocaine Maximum Recommend Dose:
mg/kg
absolute max
cartridges
6.0mg/kg
Absolute Maximum 400mg
5.5 cartridges will be the maximum # used on a patient
Prilocaine Relatively contraindicated in:
Hb?
RBC?
cardio/res?
drug?
Idiopathic / congenital methemoglobinemia
Hemoglobinopathies (Sickle cell anemia)
Anemia
Cardiac / Respiratory failure evidenced by hypoxia
Patient taking Acetaminophen or Phenacetin- Produce elevations in methemoglobin level
Bupivacaine
Potency:
Metabolism site:
Onset of Action:
Anesthetic t ½ :
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)
bupivacaine Maximum Recommended Dose:
mg/kg
absolute mg
cartridges?
Maximum Recommended Dose:
1.3mg/kg
Absolute maximum 90 mg
10 cartridges is the maximum # used on a patient
bupivacaine Primary indication
Lengthy dental procedure >90 mins pulpal anesthesia is needed
Management of postoperative pain- Reduce post-op opioid analgesics
bupivacaine not recommended on
Younger patient
Physically / mentally disabled person
phases of effective pain management
pre op
peri op
post op
pre op pain management
pretreatment of 1 or 2 doses of NSAID
peri op pain management
Local anesthesia
Long-duration local anesthesia given upon D/C
post-op pain management
Continue oral NSAID q X hours for Y days
Articaine
Potency:
Metabolism:
Onset of Action:
Anesthetic t ½ :
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
Articaine Maximum Recommended Dose:
Maximum Recommended Dose:
7mg/kg
Articaine Contraindications:
allergies to?
sensitive to?
caution with what dx?
cardio?
children?
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
down side of articaine
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
Is 4% articaine too concentrated?
Is 4% too concentrated?
Animal studies show increased
neurological deficits with 4%
lidocaine
Human studies show the same
with 5% lidocaine
closet to ideal anesthetic
2% lidocaine with 1:100,000
epinephrine is still the closest to
the ideal intermediate-duration
local anesthetic in dentistry.
Topical anesthesia is effective only on?
This is sufficient to allow?
Topical anesthesia is effective only on
surface tissue (2-3mm)
This is sufficient to allow atraumatic needle
penetration
Benzocaine
chemical structure?
cardio absorbtion?
injection?
allergies?
most commonly used as?
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
Lidocaine (Topical) forms
Two forms
Lidocaine base- Poorly soluble in H2O
Lidocaine hydrochloride
• Water soluble
• Better tissue penetration but systemic absorption is also greater
Maximum recommend dose of topical lidocaine
Maximum recommend dose is 200mg
Keep in mind for the “other” injection lidocaine !!!
2% lido with 1:100000 epi pulpal/soft tissue length
pulp:1h
soft: 3-5h
3% mepivicane pulpal/soft tissue length?
pulp:5-10min
soft: 1.5h
0.5% Bupivacaine +Epi
1:200,000 pulp/soft tissue length?
pulp: >1h
soft: 4-12 (h)
Articaine 4% + epi 1:100,000 pulp/soft length
pulp: 0.5(h)
soft: 3-5 (h)
