Local anesthesia three Flashcards
Individual response to drug is a Bell shaped curve phenomenon
Accuracy in deposition of local anesthesia
Tissue status (vascularity, pH)
Anatomical variation
Types of injection administered (block or infiltration)
Factors affecting both depth and duration of anesthesia
t/f: Larger than recommended doses do NOT increase duration !!!
true
Determining Maximum Recommended Dosages:
Different mg/kg MRDs dependent on inclusion of vasoconstrictor
Manufacturer’s recommendation
Old Days
Determining Maximum Recommended Dosages:
No distinction / adjustment made for inclusion of vasoconstrictor
Council on Dental therapeutics of the American Dental Association
United States Pharmacopeal Convention
Currently
Maximum calculated drug dose should_____ in medically
compromised, debilitated, or elderly persons
decrease
t/f: when exceeding MRD, there is a greater likelihood of OD arising
true, but it doesn’t guarantee an OD.
t/f: OD may arise at the dosage below the calculated MRD (hyper-responders)
true
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.
Drug Information: Potency: the standard Metabolism: liver Onset of action: rapid (2-3 mins) Anesthetic t ½ : 1.6 hours
Lidocaine
What is the MRD of Lidocaine?
Maximum Recommended Dose (MRD)
4.4mg/kg (Council on Dental Therapeutics of the ADA and USP convention)
Absolute maximum 300mg
8 Cartridges will be the maximum # used on a patient
What are other limiting factors of Lidocaine?
**BOARDS****
Healthy patient, maximum epinephrine is 0.2mg or 200mcg
Cardio patient , maximum epinephrine is 0.04mg or 40mcg
Conclusion:
What is the sequence of limiting the maximum dose of lidocaine?
- First: maximum amount of epinephrine can be given
* Second: lowest possible dosage of lidocaine needed
First Amide to be marketed and replaced procaine (Novocain) as
the drug of choice
lidocaine
t/f: Allergy to amide (lidocaine) is virtually nonexist
true
What is the most common type of cartridge of lidocaine?
2% w 1:100,000
Drug Info:
Potency: similar to lidocaine
Metabolism: Liver
Onset of action: Rapid (1.5 to 2 mins)
Anesthetic t ½ : 1.9 hours
Mepivacaine
What is the Maximum Recommended Dose ( MRD) of Mepivacaine?
4.4mg/kg
Absolute maximum 300mg
5.5 cartridges will be maximum # used on a patient
t/f: Mepivacaine has mild vasodialating properties
true
_______ has a Longer duration vs other agent w/o vasoconstrictor
Mepivacaine
3% _______ plain provides
20-40 mins pulpal anesthesia
2-3 hours soft tissue anesthesia
Mepivacaine
When is Mepivacaine indicated?
When vasoconstrictor is NOT indicated
Most often used in pediatric / geriatric patient
Drug Info:
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
What is the MRD of Prilocaine?
6.0mg/kg
Absolute Maximum 400mg
5.5 cartridges will be the maximum # used on a patient
________ is relatively contraindicated when:
Idiopathic / congenital methemoglobinemia
Hemoglobinopathies (Sickle cell anemia)
Anemia
Cardiac / Respiratory failure evidenced by hypoxia
Patient taking Acetaminophen or Phenacetin
• Produce elevations in methemoglobin level
prilocaine
What are the two types of Prilocaine?
4% w/o vasoconstrictor
4% w vasoconstrictor
Drug Info:
Potency: 4X lidocaine Metabolism: Liver Onset of Action: Longer 6-10 mins occasionally similar to lidocaine Anesthetic t ½ : 2.7 hours (Long Duration)
Bupivacaine
What is the MRD of Bupivacaine?
1.3mg/kg
Absolute maximum 90 mg
10 cartridges is the maximum # used on a patient
_________ has been available in U.S. since 1983
Bupivacaine
What is a primary indication that Bupivacaine should be utilized?
Lengthy dental procedure >90 mins pulpal anesthesia is
needed
Management of postoperative pain
• Reduce post-op opioid analgesics
What demographic is Bupivacaine not recommended on?
Younger pt and Physically / mentally disabled person
the following combination is the run down to effective manage ______.
Preoperative
pretreatment of 1 or 2 doses of NSAID
Perioperative
Local anesthesia
Long-duration local anesthesia given upon D/C
Postoperative
Continue oral NSAID q X hours for Y days
Pain
Drug Info:
Potency: 1.5X lidocaine Metabolism: Only amide type L.A. with ester group • Plasma esterase hydrolysis • Liver metabolism Onset of Action:1-2 mins infiltration Anesthetic t ½ : 0.5 hours Maximum Recommended Dose: 7mg/kg
Articaine
The following are claims for _______ use.
Increased success rates ( don’t miss often)
Diffuse soft / hard tissue reliably
Infiltration of mandible resulted pulpal and lingual anesthesia
Controlled study failed to corroborate these claim !!!
Articaine
the following are contraindications for _______ use:
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
Articaine
______ and _____ resulted in
more non-surgical paresthesias than
all of the local anesthetics, despite
being used for fewer injections.
Articaine and prilocaine
After 55 years of clinical use, 2% \_\_\_\_\_\_\_ with 1:100,000 epinephrine is still the closest to the ideal intermediate-duration local anesthetic in dentistry.
lidocaine
t/f: Topical anesthesia is effective only on surface tissue (2-3mm)
true
Are spray devices able to deliver measured
doses?
NO
Drug Info:
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
Benzocaine
EMLA stands for what?
Eutectic Mixture of Local Anesthesia
What is the composition of EMLA?
Lidocaine 2.5% + Prilocaine 2.5%
What does the following?
Provides surface anesthesia of intact skin
Usage
Circumcision, Leg ulcer debridement and GYN procedures
EMLA
The following are directions for ____?
EMLA
EMLA is contraindicated when:
Methemoglobinemia
Infant <12 months old had other methemoglobin-inducing drugs
Amide sensitive
What are the two forms of lidocaine topical?
Lidocaine base
• Poorly soluble in H2O
Lidocaine hydrochloride
• Water soluble
• Better tissue penetration but systemic absorption is also greater
What is the MRD of Lidocaine topical?
Maximum recommend dose is 200mg
Drug information:
Long-duration ester local anesthetic
Injection or topical application
Usage should limit to small area
Rapidly absorbed through mucous membrane
Extreme caution urged b/c great potential for systemic
toxicity
Tetracaine Hydrochloride
Which two local anesthetics have long duration for post opt pain control?
Bupivacaine or Prilocaine
What is the recommended local anesthetic for post opt pain control for Children / mentally disabled?
Mepivacaine
What is important for picking a LA that also needs to maintain hemostasis?
Use epi with 1:100,000 or 1:50,000
_______ contraindicatipon: true, documented reproducible allergy
Absolute
_______ contraindication: find a better substitute (ex: amide for atypical
pseudocholinesterase patient)
relative
For pulpal anesthesia ______ lasts 1 (h)
2% Lidocaine + Epi 1:100,000
For Soft tissue anesthesia _______ lasts 3-5 hours
2% Lidocaine + Epi 1:100,000
3% Mepivacaine lasts
5-10 (mins) for ______ and 1.5-2 (h) for ___ ____.
pulpal: 5-10 (mins)
Soft Tissue: 1.5-2 (h)
- 5% Bupivacaine +Epi
1: 200,000
> 1 h for _____ and 4-12 hr for ____ ____
Pulpal: >1 h
Soft tissue: 4-12 hr
Articaine 4% + epi 1:100,000
______ :0.5(h)
______ _____ : 3-5 (h)
Pulpal: 05 H
Soft Tissue: 3-5 hours
