Week 3 Flashcards
MOA of topical anesthetics
decrease Na+ ion permeability -> decrease depolarization
T/F: The best method for topical anesthetics is using a cotton tip applicator.
False! the choice of method is based on the individual pt
Which TA is associated with methemoglobinemia
benzocaine spray
Why do we need the site to be dried with gauze or sponge before we apply the TA?
dryer site = will absorb the anesthetic better
Name some characteristics of benzocaine
it’s an ester
low toxicity
duration: 5-15 mins
no MRD
methemoglobinemia is associated with the spray version
Name some characteristics of lidocaine
it’s an AMIDE
low toxicity
lasts for 15-45 mins
MRD: 300 mg but we can give 200mg safely
category B pregnancy
Benzocaine + Butamben + Tetracaine = ?
cetacaine
Name some characteristics of cetacaine
it’s a combo product
it’s an ester
lasts for 30-60 mins
MRD: 200mg
category C pregnancy
T/F: The concentration of topicals are lower than injectable LA’s.
False!! They’re higher
T/F: There are NO vasoconstrictors in topicals
True!
Know the toxicity and adverse rxns of topicals
-irritation @ site
-sloughing
-taste alteration
-CNS effects
-CV effects
What do a (+) and (-) for the aspiration mean?
(+) means blood entered the carpule
(-) no blood but small bubble may enter carpule
The larger the gauge the _______ the diameter
smaller
What is the weakest part of the needle?
Hub + Needle Adaptor
what are the 2 needle lengths commonly used in dentistry?
Long: 32mm
Short: 20mm
The needle length selection is based on?
the amount of tissue that must be penetrated
T/F: A long needle is always required for a mandibular block
True
How much LA does the stopper remove?
0.2mL
the carpule has 2mL total and the solution is 1.8mL
What can cause a pt to experience syncope?
drastic drop in BP
emotional response to injection
How can we help a pt experiencing syncope?
-supine position
-cool damp cloth on forehead
-ammonia capsule or 100% O2
What is the most common cause of a LA overdose?
injecting into a vessel
T/F: High doses of LA result in CNS and CV depression
True
Name some common causes of an allergic rxn
-methyparaben
-sodium bisulfite
-ester topicals
What could cause a burning feeling during injection?
contaminated or expired anesthetic
heated anesthetic solution
Name some causes of hematoma
puncture of blood vessel
poor technique
multiple needle penetrations
How do we prevent facial paralysis?
contact bone BEFORE depositing the anesthetic
Facial paralysis can be caused by LA being deposited into the _________ gland.
parotid
List some local complications
1) needle breakage
2) pain during injection
3) burning during injection
4) hematoma
5) facial paralysis (transient)
6) paresthesia
7) trismus
8) infection
9) edema
10) soft tissue injury
11) tissue sloughing
Which branch of CNV has sensor and motor
CN V3
Name the 5 major branches of CNV2
1) nasopalatine
2) greater palatine
3) PSA
4) infraorbital -> ASA and MSA
5) zygomatic
Which nerves emerge from the anterior and posterior trunks of CNV3?
anterior: long buccal N and muscular branches
posterior: IA nerve, lingual N, auriculotemporal N
5 major branches of CNV3
1) long buccal
2) muscular branches
3) auriculotemporal
4) lingual
5) IA
T/F: The facial nerve courses through the parotid gland
true! gotta be careful of it when doing mandibular block
Branches of maxillary A in the infratemporal fossa
1) middle meningeal
2) inferior alveolar -> mental + incisive
3) mm of mastication
4) buccal
Branches of maxillary A in pterygopalatine fossa
1) PSA
2) infraorbital -> ASA
3) greater palatine
4) sphenopalatine
What protects the maxillary A from being compressed during mandibular movement?
pterygoid plexus
What is associated with hematoma and spread of infection? hint: venous
pterygoid plexus
