Pain and Anxiety Week 3 Flashcards
(146 cards)
1
Q
What is the mechanism of action for topical anesthetics?
A
- Blocks nerve conduction at mucous membrane surfaces
- Decreases Na+ permeability = decreases depolarization = blocks nerve impulse
(MOA is similar to injectable LAs)
2
Q
What are the different forms of topical anesthetics?
A
Gel
Ointment
Metered and unmetered sprays
Cream
Liquid
Lozenges
3
Q
What is the range of effective concentrations for topical anesthetics? What does this depend on?
A
0.2% - 20%, depends on form
4
Q
What is the choice of method of delivery for topical anesthetic based on?
A
Each individual patient
5
Q
Which topical anesthetic is associated with methemoglobinemia?
A
Benzocaine sprays
(recall that injectable procaine has the same issue)
6
Q
Why do we need the site to be dried with gauze or sponge before we apply the topical anesthetic?
A
dryer site = will absorb the anesthetic better
(won’t get washed away by saliva)
7
Q
How long should topical anesthetic be placed at site?
A
1-2 mins
8
Q
What is the tissue depth of topical anesthetic?
A
2-3 mm
9
Q
What are 3 common topical anesthetics used in dentistry?
A
Benzocaine
Lidocaine
Combination of Benzocaine + Butamben + Tetracaine = Cetacaine
10
Q
Is Benzocaine (topical) an ester or amide?
A
Ester
11
Q
Which topical has a very low toxicity due to the fact that it has SLOW absorption?
A
Benzocaine
12
Q
What is the onset of Benzocaine (topical)?
A
30 seconds - 2 mins
13
Q
What is the duration of Benzocaine (topical)?
A
5-15 mins
14
Q
Which topical has a 20% concentration?
A
Benzocaine
15
Q
Where is Benzocaine (topical) metabolized?
A
Plasma + some liver
16
Q
What is the MRD of Benzocaine (topical)?
A
None
17
Q
What is the pregnancy category for Benzocaine (topical)?
A
pregnancy = category C; lactation unknown safety
18
Q
What is Benzocaine (topical) spray associated with?
A
Methemoglobinemia
19
Q
Which topical has a very low toxicity due to the fact that it has POOR absorption?
A
Lidocaine
20
Q
Which topical is good for those with an ester allergy?
A
Lidocaine
21
Q
Is Lidocaine (topical) an ester or amide?
A
Amide
22
Q
What is the onset of Lidocaine (topical)
A
2-10 mins
23
Q
What is the duration of Lidocaine (topical)
A
15-45 mins
24
Q
Which topical has a concentration of 2%-5%?
A
Lidocaine
25
Where is Lidocaine (topical) metabolized?
Liver
26
What is the MRD for Lidocaine (topical)?
MRD = 300 mg, but we use 200 mg safely
27
What is the pregnancy category for Lidocaine (topical)?
pregnancy = category B; small amount enters breast milk
28
What is Cetacaine (topical) a combination of?
Benzocaine + Butamben + Tetracaine
29
Is Cetacaine (topical) an ester or amide?
Ester
30
T/F: Benzocaine, Lidocaine, and Cetacaine are all topicals that have a very LOW toxicity
True
31
What is the onset of Cetacaine (topical)?
30 seconds
32
What is the duration of Cetacaine (topical)?
30-60 mins
33
What is the concentration of Cetacaine (topical)?
14% benzocaine + 2% butamben + 2% tetracaine
34
Where is Cetacaine (topical) metabolized?
Plasma + some liver
35
What is the MRD for Cetacaine (topical)?
MRD = 200 mg
36
What is the pregnancy category for Cetacaine (topical)?
pregnancy = category C; lactation - use caution
37
Topical anesthetics increase ________ __________, which increases ___________
blood levels; toxicity
38
T/F: The concentration of topicals are lower than injectable LA's.
False!! They're higher
39
Why do we need a higher concentration in topical anesthetics?
Must diffuse thru mucous membranes
40
T/F: There are NO vasoconstrictors in topicals
True
41
Because there are NO vasoconstrictors in topicals, there is an increased __________ __________ and therefore an increased _____________
absorption rate; toxicity
42
Which groups of people have an increased risk of toxicity and adverse reactions to topical?
Elderly
Children
Medically compromised
43
What are the toxicity and adverse reactions of topical anesthetic?
Irritation @ site
Sloughing
Taste alteration
CNS effects (excitation -> depression)
CV effects (decreased HR/BP; cardiac arrest)
44
T/F: The CNS and CV effects of toxicity/adverse reactions in topical anesthetic have the same signs and symptoms as in injectable LAs
True!
45
What are the 7 ways to avoid toxic rxns from topicals?
1. Know relative toxicity of drug
2. Know concentration of drug
3. Use smallest volume
4. Use lowest concentration
5. Use least toxic drug
6. Limit area of application
7. Avoid sprays
46
What does a (+) and (-) result for the aspiration test mean?
(+) aspiration = blood entered carpule
(-) aspiration = no blood; small bubble may have entered carpule
47
What is aspiration test and what does it determine?
Negative pressure within a cartridge prior to injecting to determine if needle is within a blood vessel
48
Angled surface of the needle tip
Bevel
49
Diameter of a needle
Gauge
50
The larger the gauge, the __________ the diameter
smaller
51
What is the weakest part of the needle?
Hub
52
What does the hub + needle adaptor attach?
Attaches needle to syringe adaptor
53
What materials can the hub + needle adaptor be?
Plastic or aluminum
54
What does a plastic hub + needle adaptor allow for?
Movement to align bevel
55
Why is the hub + needle adaptor usually marked with ink?
For bevel location
56
What is the end of the needle shaft that penetrates the diaphragm of the carpule?
Carpule-penetrating end
57
When should the carpule-penetrating end be placed?
After carpule is loaded and the harpoon is engaged
58
What must remain covered until ready for use?
Needle shaft
59
What are the 2 needle lengths commonly used in dentistry?
Long = 32 mm
Short = 20 mm
60
What is needle length selection based on?
Amount of tissue that must be penetrated to reach target location
61
Where should the needle NEVER be inserted to?
The hub
62
What needle length is ALWAYS required for a mandibular block?
Long
63
Each needle is used on _____ pt
one
64
________ _______ remains over needle until ready to inject
Plastic shield
65
When should the needle be replaced?
After 3-4 penetrations (dulls the tip)
66
What should you do immediately after done injecting?
Cover needle with plastic shield, using the 1-handed scoop technique
67
You should know where an _________ _________ is at all times
uncovered needle
68
What should you do if a needle becomes contaminated?
Recap and dispose; replace needle
69
Where should you put all contaminated needles?
Approved sharps container
70
How many mL of LA are in each carp? How many mL does the stopper remove?
1.8 mL
Stopper removes 0.2 mL
71
What are 5 systemic complications of LA?
1. Syncope
2. LA overdose
3. Epi overdose
4. Allergic rxn
5. Any potential medical emergency
72
Causes of syncope
Drastic drop in BP
Emotional response to injection
73
Prevention of syncope
Identify fearful pt in pre-anesthetic assessment
Hide needle
Supine position
74
Symptoms of syncope
Sweating, nausea, pallor
Increased HR and RR
75
Treatment for syncope
Supine position w/ legs higher than head
Ammonia capsule or O2
Cool damp cloth on forehead/neck
Monitor vitals
Reassure pt (don't let them sit up or stand)
76
Causes of LA overdose
Injecting into vessel (MOST COMMON)
Administering too large of dose
Metabolism/excretion of LA is slow
77
Prevention of LA overdose
Aspirate in 2 planes
Calculate MRD
Pre-anesthetic assessment for LA selection
78
Symptoms of LA overdose
CNS excitation (low overdose)
CNS/CV depression (higher overdose)
79
What is treatment of LA overdose determined by?
Onset and severity
80
How do you treat mild LA overdoses?
No treatment
81
How do you treat moderate/severe LA overdoses?
Stabilize pt
Activate EMS
82
Rapid onset = ?
More severe reaction
83
Causes of epinephrine overdose
1:50,000 conc
Intravascular injection
CV pts
84
Prevention of epinephrine overdose
Aspirate in 2 planes
Use lowest effective conc.
Pre-anesthetic assessment to identify CV pts
85
Symptoms of epinephrine overdose
Fight or flight response
(lasts 5-10 mins)
86
Treatment of epinephrine overdose
Healthy pts -> reassure
CV pts -> prepare for medical emergency
87
Allergic reactions to LA can be __________ or ___________
delayed; immediate
88
Causes of allergic reactions
Methyparaben (preservative used until 80s)
Sodium bisulfite (in vasoconstrictors)
Ester topicals
89
How to prevent allergic reactions
Pre-anesthetic assessment
90
Symptoms of allergic reactions
Delayed: rash, itching
Immediate: anaphylaxis
91
Treatment of allergic reactions
Delayed: antihistamine, document
Immediate: stabilize pt, activate EMS, document
92
Examples of local complications of LA
Needle breakage
Pain/burning during injection
Hematoma
Facial paralysis
Paresthesia
Trismus
Infection
Edema
Soft tissue injury
Sloughing
93
Causes of needle breakage
Sudden unexpected movement
Poor technique
94
Prevention of needle breakage
Use 25g or 27g needles
Use long needle for IA block
Do not bend needle, insert needle to hub, or force needle
95
Treatment of needle breakage
Keep hands in pts mouth
Remove needle if visible
Refer to OS
Document
96
Causes of pain during injection
Dull/barbed needle
97
Prevention of pain during injection
Inject slowly
Use topical
Use sharp needle
Use anesthetic at room temp
98
Treatment of pain or burning during injection
Reassure pt
Slow down delivery of anesthetic
99
Causes of burning during injection
Contaminated/expired anesthetic
Heated anesthetic
100
Prevention of burning during injection
Inject slowly
Check carp before use
Store anesthetic at room temp
101
Causes of hematoma
Puncturing blood vessel
Multiple needle penetrations
102
Prevention of hematoma
Use 27 short for PSA
Know anatomy
103
Treatment of hematoma
Apply ice and pressure ASAP
Inform pt of swelling/discoloration (7-14 days)
Document
104
Causes of facial paralysis
LA deposited in parotid gland
Bone not contacted during mandibular block
105
Prevention of facial paralysis
Contact bone before depositing LA
106
Treatment of facial paralysis
Reassure pt
Document
107
Causes of parasthesia
Trauma to nerve sheath (pt feels a shock)
Edema/hemorrhage near nerve
Contaminated anesthetic (soaked in disinfectant)
Possible association w/ Articaine
108
Prevention of parasthesia
Minimize needle within tissue
Do NOT soak carps in disinfectant
109
Treatment of parasthesia
Reassure pt (3 weeks - 3 months; possibly 1 year)
Document
110
Causes of trismus
Muscle trauma from multiple needle insertions
Contaminated anesthetic
111
Prevention of trismus
Use sharp needle
Inject slowly
Store anesthetic properly
112
Treatment of trismus
Reassure pt (2-3 days)
Moist heat (20 mins on/20 mins off)
Document
113
Causes of infection
Contaminated needle/cartridge
Administer anesthetic thru infected area
114
Prevention of infection
Sterile needle -> replace if contaminated
Store anesthetic properly
Do not inject infected area
115
Treatment of infection
Antibiotics after 3 days
116
Causes of edema
Trauma
Contaminated needle
Allergic rxn
117
Prevention of edema
Good technique
Pre-anesthetic assessment to identify allergies
Store anesthetic properly
118
Treatment of edema
NONE (goes away 3-4 days)
119
Causes of soft tissue injury
Self-inflicted (usually kids)
120
Prevention of soft tissue injury
Select LA w/ appropriate duration
Warn pts/parents
121
Treatment of soft tissue injury
OTC analgesics
Antibiotics if severe
Warm salt water rinse
Vaseline for lips
122
Which branches of CN V have sensory only?
CN V1 + CN V2
123
Which branch of CN V has sensory + motor?
CN V3
124
CN V1 opening
Superior orbital fissure (sphenoid bone)
125
3 major branches of CN V1
Nasociliary
Frontal
Lacrimal
(NFL)
126
CN V2 opening
Formen rotundum (sphenoid bone)
127
CN V2 enters the...
Pterygopalatine fossa
128
5 major branches of CN V2
Nasopalatine
Greater palatine
PSA
Infraorbital -> ASA + MSA
Zygomatic
129
CN V3 opening
Foramen ovale (sphenoid bone)
130
3 trunks of CN V3 and their contents
Undivided: muscular branches
Anterior: long buccal nerve + muscular branches
Posterior: IA, lingual, auriculotemporal nerves
131
5 branches of CN V3
Long buccal
Muscular branches (to mm of mastication)
Auriculotemporal
Lingual
IA -> mylohyoid, mental, incisive
132
What does CN VII do?
Motor to mm of facial expression
Sensory to ant 2/3 tongue (taste)
133
Path of CN VII
1. Internal acoustic meatus
2. Stylomastoid foramen
3. Parotid gland (no innervation)
134
What branches of CN VII are in the internal acoustic meatus?
Chorda tympani (submandibular/sublingual glands)
Greater petrosal (lacrimal gland)
135
What branches of CN VII are in the parotid gland?
Temporal
Zygomatic
Buccal
Mandibular
Cervical
136
What cranial nerve wraps around the parotid gland?
CN VII
(be careful when doing mandibular block!)
137
What does the external carotid artery terminate as?
Maxillary artery
Superficial temporal artery
138
Where does the maxillary artery begin within?
Parotid gland (at neck of mandibular condyle)
139
The maxillary artery runs between ___________ and ___________ ____________ (lingula)
mandible; sphenomandibular ligament
140
The maxillary artery enters the __________ fossa and then the ___________ fossa, giving off 4 branches at each
infratemporal; pterygopalatine
141
4 branches of maxillary artery within infratemporal fossa
1. Middle meningeal
2. Inferior alveolar -> mental + incisive + mylohyoid
3. Branches to mm of mastication
4. Buccal
142
4 branches of maxillary artery within pterygopalatine fossa
1. PSA
2. Infraorbital -> ASA
3. Greater palatine
4. Sphenopalatine -> nasopalatine
143
What protects the maxillary A from being compressed during mandibular movement?
Pterygoid plexus
144
What is associated with hematoma and spread of infection during incorrectly administered PSA injections?
Pterygoid plexus
145
What is a venous plexus of small anastomosing vessels?
Pterygoid plexus
146
Where is the pterygoid plexus located?
Around pterygoid muscles; surrounds maxillary artery in infratemporal fossa
