Test 1 Flashcards
1
Q
Afferent vs Efferent
A
Afferent to the CNS
Efferent from the CNS
2
Q
What are the properties that are necessary to make a local anesthetic clinically useful?
A
- Compatible with the tissues and non irritating.
- Actions should be temporary and completely reversible.
- Effective in doses far below its toxic level.
- Hypoallergenic.
- Rapid onset of anesthesia with a duration of action sufficient to complete the dental procedure comfortable.
3
Q
Two functional groups of local.
A
Amides and esters.
4
Q
Are topicals typically esters or amides?
A
Esters.
5
Q
What are some of the esters?
A
Procain, novocaine, etc.
6
Q
What are some of the amide locals?
A
Lidocaine (xylocaine), mepivacaine (carbocaine), prilocaine (citanest), Bupivacaine (marcaine), etidocaine (duranest)
7
Q
Lidocaine
A
xylocaine
8
Q
Mepivacaine
A
Carbocaine
9
Q
Prilocaine
A
Citanest
10
Q
Bupivacaine
A
Marcaine
11
Q
Etidocaine
A
Duranest
12
Q
Why are amides preferable to the esters?
A
The means by which the body breaks down the substance of the drug is less likely to cause an allergic reaction. Additionally, the lipid solubility, potency, duration of action and ionization constant are all perferable.
13
Q
Where are esters and amides broken down?
A
Esters are reduced by esterases in the tissue and amides are reduced in the liver and excreted in the kidneys.
14
Q
How does the local anesthetic interfere with how the nerve impulses travel down the length of the nerve itself?
A
Interferes with the influx of Na ions across the neural membrane. Acts during the depolarization phase of the nerve impulse generation. The rate is reduced and the nerve never reaches the firing potential.
15
Q
Where does local affect the nerves?
A
The axonal membranes of peripheral nerves.
16
Q
The Specific Receptor Theory
A
The local anesthetic interferes with the sodium channel and blocks the sodium transfer necessary for nerve conduction.
17
Q
How far must the anesthetic permeate in order to profoundly block?
A
8 to 10 mm of the nerve’s length.
18
Q
What is a reason for anesthetic not producing pain control on the second injection?
A
The lower pH of the tissues, edema, hemorrhage or transudation in the surrounding area. Once the nerve has returned to function, it usually is more difficult to achieve profound anesthesia again.
19
Q
Why isn’t anesthetic not as effective when infection is present?
A
Because the pH of the tissues is too low to allow the anesthetic to penetrate the nerve sufficiently.
20
Q
What is the largest fiber? The smallest?
A
A is the largest. C is the smallest?
21
Q
Type C Fibers
A
No myelin sheath. Responsible for carrying the sensations of pain and temperature. Smallest.
22
Q
Which fiber is most easily blocked by local anesthetic? Why?
A
Type C! The lack of a myelin sheath allows easier access to the nerve.
23
Q
Type A Fibers.
A
Largest, responsible for carrying pressure and motor sensation. Local is not as effective.
24
Q
Why can an adequately anesthetized patient always feel pressure during an extraction, but not pain?
A
Type A fibers, which are the largest, and carry pressure and motor sensation, are not effectively blocked by local.
25
What influences the uptake of local anesthetics?
1. Blood flow in the area of administration.
2. Affinity of the anesthetic for local tissues
3. Effect of the anesthetic on circulation.
4. The absence or presence of a vasoconstrictor.
26
What types of organs will have higher blood levels of anesthetic following injection?
Highly vascular organs. Brain, liver, lungs, and kidneys.
27
Following an intravascular injection, what is the sequential distribution?
First to the lungs, then other organs with large blood supplies. Especially the brain, heart, liver kidneys, spleen. Finally to muscles and fat.
28
What happens at toxic levels of local anesthetics to the CNS and CVS?
CNS and CVS susceptible. Depresses the CNS and causes the patient to have convulsions. Epileptic patients are more susceptible to seizure.
CVS is more resistant. Myocardial depression followed by circulatory collapse is not caused by a typical dental dose.
29
What metabolizes ester anesthetics? Why is this a problem in some people?
Pseudocholinesterase.
Approximately 1 in 2800 people have atypical pseudocholinesterase and can't biotransform the anesthetic at a normal rate.
30
Where are amides metabolized? Why does this cause an issue in some patients?
Liver! Patients who have liver dysfunction may have difficulty metabolizing and will reach a toxic level more quickly than a healthy counterpart.
31
When the liver isn't fully functioning, how does the body compensate in the metabolism of amides?
The kidneys then excrete the amount that wasn't metabolized in the liver.
32
Why is the vasodilation activity of local anesthetics bad?
Produces an increased rate of absorption. Decreased effectiveness, short duration of anesthesia and higher risk of toxicity. Bleeding in the area of injection is increased.
33
How do you counteract the vasodilation?
Vasoconstrictors. Decrease the absorption of the drug and prolong the anesthetic effect. Decreases the risk of toxicity because it is more slowly absorbed.
34
What needs to be considered when selecting an appropriate vasoconstrictor?
Length of the procedure, desired level of hemostasis and medical health of patient.
35
What are the most commonly used vasoconstrictors?
Epinephrine and levonordefrin (neo-cobefrin).
36
What are the handling instructions for epinephrine?
Sensitive to heat and can be inactivated if left too warm for too long. Store local in cool areas and never autoclave the cartridges.
37
Which is more potent, neocobefrin or epinephrin?
Epinephrine. 5 times the amount of neo-cobefrin is needed to produce the same results as epinephrine.
38
What concentrations of epinephrine available at? Why?
1:50,000 for better hemostasis. The anesthetic effect lasts much longer.
39
What is the rebound effect?
Vasoconstrictors are effective in producing hemostasis, but after they wear off, it may lead to increased postoperative bleeding. Especially true in higher concentrations.
40
What is the limit of cartridges of lidocaine for use on patients that are medically compromised by high bp, CV disease or hyperthyroidism?
No more than 2 cartridges of lidocaine with 1:100,000 concentration of epinephrine.
41
When is epinephrine is contraindicated in patients?
- bp over 200/115.
- Uncontrolled hyperthyroidism
- Severe cardiovascular disease, including less than 6 months after a myocardial infarction or cerebrovascular accident.
- Daily episodes of angina pectoris or unstable angina.
- Cardiac dysrhytmias despite appropriate therapy.
- Medicated with B blocker, MOIs, tricyclic antidepressents, general anesthesia with a halogenated anesthetic like halothane, methoxyflurane or therane.
42
Which reaches toxic levels easier, topical or local? Why?
Topical! The concentrations are higher and absorption is greater.
43
To what depth is topical anesthesia effective?
Only about 2-3 mm of depth into the tissues on which it is applied.
44
Why is the gel type of topical more recommended over spray?
It can be dispensed in pre-measured doses. Patient may aspirate the spray and the can is difficult to sterilize.
45
What is the commonly used topical anesthetic?
Benzocaine.
46
What is the maximum recommended dose of topical lidocaine?
200 mg.
47
What type of local anesthetic is benzocaine? An ester or an amide?
Ester. Localized allergic reactions may be noted.
48
What are some factors that influence the action of the local anesthetic?
Anatomical variation, type and method of injection, presence or absence of infection, the patient's individual response to the anesthetic, anxiety, vascularity of tissues.
49
What is the duration of bupivacaine hydrochloride, 0.5% with epinephrine 1:200,000
Greater than 90 min.
50
What is the duration of Etidocaine hydrochloride, 1.5% with epinephrine 1:200,000?
Greater than 90 min.
51
What is the duration of lidocaine hydrochloride, 2% without vasoconstrictor?
30 min.
52
What is the duration of lidocaine hydrochloride, 2% with epinephrine 1:50,000?
60 min.
53
What is the duration of lidocaine hydrochloride, 2% with epinephrine 1:100,000?
60 min.
54
What is the duration of mepivacaine hydrochloride, 3% without vasoconstrictor?
30 to 60 min.
55
What is the duration of mepivacaine hydrochloride 2% with levonordefrin 1:20,000?
60 min.
56
What is the duration of prilocaine hydrochloride 4% without vasoconstrictor?
30 min.
57
What is the duration of prilocaine hydrochloride, 4% with epinephrine 1:200,000?
90 min
58
What is the duration of articaine, 4% with epi 1:100,000?
60 min.
59
What are the symptoms of epinephrine overdose?
Fear, anxiety, restlessness, headache, tenseness, perspiration, dizziness, tremor of limbs, palpitation, and weakness.
BP and heart rate will be elevated.
60
What do you do in the case of an epinephrine overdoes?
Position patient comfortably and administer oxygen. If the patient's BP is elevated and signs of cerebrovascular incident occur, summon medical assistance. If no symptoms of cerebrovascular problems, the patient can be dismissed home.
61
How can toxicity be reached for an anesthetic?
Administering too much of the drug (body weight), administering the drug to a sensitive individual, administering the drug into a blood vessel, or by improper drug combinations.
62
What is the rate of absorption and elimination of the drug directly related to?
Its toxic effects. The faster it is absorbed by the bloodstream and the slower the metabolism of the drug, the more toxic it is to the body.
63
Why is it critical to aspirate each time an anesthetic is administered into an area that is very vascular?
An injection of even a small amount of anesthetic solution directly into a blood vessel can result in an immediate toxic level.
64
Does a negative aspiration guarantee that the needle isn't in a blood vessel?
No! Think of the bevel. Aspirate multiple times during the slow injection of anesthetic.
65
How do CNS depressants affect the toxicity of local anestheticss?
Reduce the toxic level.
66
What are the 5 types of syringes that are available for dental use?
Breech-loading, metal (aspirating, self aspirating, or non-aspirating), pressure injectors, jet injectors, plastic (autoclavable or disposable)
67
What is the most common syringe used?
Metal aspirating type.
68
Why would one use a plastic syringe?
Lighter and more esthetically pleasing to anxious patients.
69
What are pressure syringes used for? Why?
Intraligamentary injections or PDL injections. The mechanics of the syringes make the administration of these higher pressure injections much easier. If administered too quickly, you can have damaged or bruised tissues. Need to administer slowly to reduce damage to the tissues.
70
Why should a needle never be inserted to its hub?
It is the most likely place for a needle to break.
71
What should Long, 25 gauge needles be used for?
The IA nerve block, the Gow-Gates MN nerve block and the Akinosi MN nerve block .
72
Why would you want to use a larger gauge needle vs a smaller guage needle?
More accurate aspiration. Smaller needles tend to bend and deflect as they are inserted into tissue, so the accuracy of the injection can be compromised.
73
How many times can you use a needle before you need to change it?
3-4 times. It becomes dull and patients feel it. Check also for barbs using gauze. Barbs cause pain during withdrawal of the needle.
74
What are the descriptive characteristics of the beat?
Strong, steady, bounding, thready, or weak. Strong and steady is a normal healthy pulse. Anything else indicates a problem.
75
What is a normal respiration rate?
16-18 breaths per min.
76
How much anesthetic in solution is there in a single cartridge/carpule?
1.8 ml.
77
What is contained in the solution in the cartridge?
Local anesthetic, sodium chloride, distilled water, and if indicated, a vasoconstrictor drug with preservative.
78
What was the preservative that most likely causing the allergic reactions in patients?
Methylparaben.
79
What are the issues with sodium bisulfite or metabisulfite? What are they used for?
May be a problem in sensitive individuals, specifically, asthmatics that have had a reaction to bisulfites. They have antioxidant properties and are used in anesthetic cartridges containing a vasoconstrictor as a preservative.
80
What is on the end of the cartridge where the needle is inserted?
Aluminum cap and a semipermeable rubber membrane.
81
Why shouldn't you soak the cartridge in alcohol?
The alcohol may diffuse into the solution through the diaphragm.
82
What does it mean when there is a large bubble and the rubber stopper is extruding from the end of the carpule?
May have been damaged or frozen. Return the whole can to the manufacturer.
83
What are some common errors in taking blood pressure?
Cuff too loose (high reading), wrong cuff size, not palpating the pulse and underinflating the cuff, using visual cues rather than audio indicators.
84
What are the guidelines for treatment with patients with high blood pressure?
Less than 140/90, good to go.
140-159/90-94, routine dental care is okay, but if it is consitently high, refer to physician.
160-200/95-114, retake after waiting for 5 min. If still high, refer to physician and consider stress reduction instruction. Routine dental care can be delivered, but consultation with physician is recommended before anesthesia is given.
Over 200/115, recheck it after 5 min and if it is still elevated, consult with their physician. If treatment is necessary, may need to be done in the hospital.
85
What is the only accurate way to diagnose a true allergy to anesthetics?
Order a potency test from the patient's physician. Allergies are rare, but possible. For most, they only had a hematoma, trismus, or felt anxious because of the vasoconstrictor.
86
What happens if a patient is truly allergic to all local anesthetics?
All dental work involving pain should be conducted in the hospital under general anesthesia.
87
What position do you put a patient in when giving local to reduce the incidence of fainting?
Reclined comfortably with head parallel to the heart and feet raised slightly.
88
When do you first communicate with the patient that you are taking steps to make sure that the procedure will be as comfortable as possible?
When you are using gauze to dry the area of injection.
89
What is the determining factor to the extent of anesthetic effect?
The area where the local anesthetic is deposited, relative to the nerve of the tooth to be anesthetized.
90
Why are local infiltration techniques relatively limited to the area of deposition?
They deposit the solution near superficial nerve endings and the pain reduction are limited. Used to treat isolated areas.
91
Field block anesthesia technique
Deposit solution near terminal branches of nerves to provide anesthesia for a wider area of treatment. 2 or three teeth.
92
Nerve block technique
Deposit the anesthetic close to the main nerve trunk and allow for wider area of treatment with profound anesthesia.
93
What teeth are anesthetized in supraperiosteal injections? What type of injection is it? When is it indicated? What is the technique?
Most popular injection for Pulpal anesthesia of MX anterior teeth. Field block. Ideal for pulpal and soft tissue anesthesia. Contraindicated for infection near the apex of the tooth or if the bone is very dense.
25 or 27 gauge needle. Inserted at the height of the mucobuccal fold near the apex of the tooth.
94
What teeth are anesthetized in the Posterior Superior Alveolar Nerve Block? What needle is used? Technique?
Maxillary molars. Short 25 or 27 gauge needle (decrease risk of a hematoma). Insert at the mucobuccal fold by the MX second molar with the bevel toward the bone. Route is up, back, and inward towards the PSA nerve. Inserted approximately 16 mm.
95
In the PSA, what may necessitate an additional MSA block?
The PSA nerve in some patients does not innervate the MB root of the first molar.
96
In the Middle Superior Alveolar Nerve Block, how many patients need it? When is it needed? Technique?
Only about 20% of patients have it. Infraorbital nerve block should provide adequate anesthesia. If it doesn't, or the PSA doesn't cover the MB root of the first molar, then do a MSA. Insert by the MX 2nd premolar at the height of the apex.
97
In the infraorbital nerve block, what is anesthetized? Why is it preferred to multiple supraperiosteal injections? What nerves does it anesthetize? Technique?
MX Central incisor to the PM area. Preferred because less anesthetic and only 1 penetration. ASA, MSA, inferior palpebral nerve, lateral nasal nerve and superior labial nerve. Especially effective for infection.
Locate infraorbital foramen. Insert over the first premolar, parallel with the long axis of the tooth. 16 mm depth. Pressure.
98
Technique for palatal injections.
Dry, swab with antispetic solution, apply topical, blanch with blunt object, deposit slowly.
99
What does a greater palatine nerve block anesthetize? Technique?
Palatal tissues and bone distal of the canine. find foramen, medial to second molar. Use bevel pressure technique.
100
What does the Nasopalatine Nerve Block anesthetize? Technique?
Anterior of the hard palate from the mesial of the premolar bilaterally. Same technique as the greater palatine nerve block. You can infiltrate in the muvobuccal fold near the frenum, then the papilla between the incisors, then the nasopalatine injection.
101
When is the maxillary nerve block used? Where else can it be accessed?
Used in quadrant surgery or when extensive treatment is indicated. Also in the case of infection. Goes into the pterygopalatine fossa. Also can be accessed through the greater palatine foramen.
102
Why is MN anesthesia success rates lower than MX?
The bone is denser around the MN apices, which inhibits the diffusion. Anatomical variations.
103
Where does the IA provide anesthesia?
MN teeth to the midline, body of the MN, buccal mucosa and bone of the teeth anterior to the MN first molar, anterior 2/3 of the tongue and floor of the mouth and the mucosa and bone lingual to the MN teeth.
104
What needle should you use for the IA? Why?
25 gauge long needle. A 27 or 30 will be deflected or bent.
105
Where should the tissue be penetrated on an IA?
The medial border of the MN ramus at the height of the coronoid notch at the pterygomandibular raphe. 1.5 cm above the MN plane. Barrel should be parallel with the occlusal plane of the MN molars and come across the PM of the opposite quadrant. Anesthetic delivered directly above the MN foramen.
106
How far with the needle be advanced in an IA block in an adult patient?
20-25 mm, or about 2/3 of the length of the needle.
107
If bone is contact in an IA too early, how should you reposition? If it is not contacted?
Too early: move mesially.
| Too late: move distally.
108
In the IA when do you get the lingual nerve?
When you are withdrawing, stop at 1/2 the length and aspirate.
109
What are common problems with the IA?
Deposited below the MN foramen. Deposited too far anteriorly. Needle deflected by tissue and anesthetic deposited to the left or right of foramen. Anesthetic doesn't reach the nerve. Accessory nerves supplying MN teeth.
110
What do you do if the anesthetic in an IA doesn't reach the nerve?
Use anesthetic without vasoconstrictor for a second injection to allow for diffusion.
111
What does the Buccal Nerve block anesthetize? When is it necessary? Technique?
Tissues and periosteum buccal to the molars. Only used when soft tissues are involved in the treatment. If teeth only, it isn't necessary. Follow immediately after IA. Pull tissues taught. Needle is inserted distal buccal to the last molar. Go until bone (2-4 mm) aspirate, deposit.
112
What does the Gow-Gates anesthetize? When is it used?
The MN teeth to the midline, buccal tissues and bone, floor of hte mouth, tongue to the midline, lingual tissues and bone, the body of the MN and the skin over the zygoma.
Quadrant dentistry or when the IA block fails.
113
Technique for Gow Gates?
25 gauge needle. Mesial of the ramus, on an imaginary line from the intertragic notch to the corner of the mouth, distal to the MX 2nd molar. Inject just below the ML cusp of the MX 2nd molar. Keep barrel of needle over MN premolars. Use the tragus and 2nd molar as land marks. Keep parallel with imaginary line. Advance until bone is contacted at the neck of the condyle. About 25 mm. After injected, keep mouth open. May take longer because denser nerve, and area of deposition is farther away.
114
When is the Akinosi Closed Mouth Technique used? What does it anesthetize?
When the patient has a limited MN opening. It anesthetized the MN teeth to the midline, the body of the MN and part of the ramus, buccal tissues and bone anterior to the mental foramen, the tongue and floor of the mouth and the lingual tissues and bone.
115
Technique for the Akinosi CMT? What happens?
25 guage long needle. Insert needle in soft tissue over the medial border of the MN ramus adjacent to the MX tuberosity in the mucogingival junction by the third molar. Not as high as GG, but higher than IA. Mesial to the ramus, but lateral to the tuberosity. The barrel of the needle is parallel with the occlusal plane. 25 mm. Tip should be in pterygomandibular space, not contacting bone. Seat patient upright.
Motor nerve paralysis and allow patient with trismus to open freely.
116
What does the mental nerve block anesthetize? When is it useful? Technique?
Soft tissues anterior to the foramen. Located at the apecies of the premolars. Doesnt' get the teeth.
Useful for curettage or biopsy. If you did a IA nerve block, there is no need for this.
Inserted in the mucobuccal fold near the mental foramen. Bevel toward the bone. Palpate the foramen before you give.
117
What is the difference between a mental nerve block and an incisive nerve block?
Incisive nerve innervates the lower teeth anterior to the mental foramen to the midline. The incisive nerve runs inside the foramen, so the needle needs to be directed into the foramen, but is in the same area as a mental nerve block. Anesthetic must diffuse into the foramen to affect the incisive nerve. Pressure.
118
Why is a PDL injection better in the MN than the MX? What does it anesthetize?
Bone is too dense for good diffusino fomr a supraperiosteal injection. Used as an adjunct.
Tooth, bone, soft tissue, apex and pulpal tissues in the area of injection.
119
Where does the anesthetic diffuse in a PDL injection? Technique?
Apically through marrow spaces in the intraseptal bone. Sulcus, 27 guage short. MAY need to bend for posterior teeth. Only time that is acceptable. Advance apically until resistance is met. Deposite .2 ml, or a stopper worth. Shouldn't escape back up the sulcus. Performed for all roots of the tooth. Duration variable.
120
When is an intraseptal injection used? Technique?
Hemostasis, soft tissue anesthesia and osseous anesthesia. Insert inot the papilla of the area to be anesthetized at an angle of 90 degrees to the tissue.
121
What is a benefit of an intraosseous injection?
When anesthetic is deposited into local tissues, it is affected by the conditions of the tissues. When put in the bone through a hole in the cortical plate, the tissue can't affect it. Only does the area of treatment, not the quadrant.
122
Technique of intraosseous injection.
Topical, and small amount of anesthetic injected into the mucous membrane. Use perforator attached to the high speed drill, bores a hole of 0.43 mm through the cortical plate. Needle of .4 mm is inserted and less than 1 cartridge is delivered. Needle must be at corret angulation and depth or it will leak out.
123
What is the maximum amount of anesthetic for the intraosseous injection.
MAX 1 per visit!
124
What are the benefits of the intraosseous technique?
Onset is quick and profound without numbing the tongue and lips. No palatal injection required. Painless and less time spent waiting.
125
How does an infection at the apex affect anesthetic?
Lowers the pH and the anesthetic is neutralized and rendered less effective. The low pH in the extracellular space reduces the proportion of anesthetic in the lipophilic free base form and reduces the anesthetic's ability to cross the nerve sheathe and membrane.
126
What are some alternate techniques for anesthetizing an area with an infection?
Deposit away from the area of infection, further upt hte nerve where the pH is normal.
Regional nerve block if abscess is present.
Intrapulpal injection after it has been exposed with PDL used to make anesthesia more profound.
Intraosseous.
127
What is thought to be the cause of the mild burning sensation during administration of anesthetic?
The pH of the solution, contamination of the local anesthetic or a solution that has been warmed too much.
The piH is unavoidable and will dissipate.
128
What causes paresthesia? Is it permanent?
Damage to the nerve through the needle passing through. If there is a shooting feeling dring the injection, that would indicate contact with the nerve. If the anesthetic has been contaminated, there can be tissue irritation and edema which in turn will constrict the nerve and lead to paresthesia.
Not long term or permanent.
129
What do you do if you patient has paresthesia?
CHART THAT SHIT. Make an appointment for examination. Can resolve itself within 2 months with out treatment. Examine every 2 months until sensation returns. If continues after 1 year, refer to a neurologist or oral surgeon. If more dental treatment is needed, don't inject in the same spot, as you don't want to further cause trauma to the nerve. Use alternate techniques. Most important is communication with the patient.
130
What causes a hematoma?
Nicked artery or vein.
131
Where do hematomas most often occur?
During a PSA or IA.
132
What do you do if a hematoma occurs during an IA?
Apply pressure to the medial aspect of the mN ramus. Manifestations will usually be intraoral.
133
What do you do for a hematoma occurring during an infraorbital nerve block?
Apply pressure to the skin directly over infraorbital foramen.
134
What do you do if a hematoma occurs?
Make note and talk to them. Advice of possible soreness, analgesics if there is soreness. Do not apply heat to the area for 4-6 hours. You should start heat therapy the following day. Will disperse within 7 to 14 days with or without treatment.
135
What is Trismus? What causes it? Why do you need to treat it?
A motor disturbance of the trigeminal nerve that results in a spasm of the masticatory muscles causing difficulty in opening the mouth. Can be caused by trauma to muscles or blood vessels in the infratemporal fossa, injection of alcohol or sterilizing solution contaminated local causing irritation to the tissues, hemorrhage, large volumes of anesthetic deposited in one area or infection. If not treated, a chronic phase may develop leading to hypomobility, fibrosis and scarring.
136
How do you prevent trismus?
Use of disposable needles, antiseptic cleansing of the injection site, aseptic technique and atraumatic injection technique.
137
Recommended treatment for trismus?
Heat therapy with moist hot towels 20 min every hour, analgesics and muscle relaxants if necessary.
Exercise area by opening, closing and lateral excursions of MN for 5 min every 3 to 4 hours. Gum helps with this.
RECORD! Avoid treatment in area. If treatment is necessary, use an Akinosi MN nerve block to loosen the motor nerves.
Continue therapy until no more symptoms. If pain for more than 48 hours, think infection and Abx therapy for 7 full days. If those don't work, refer.
138
How long do you wait to prescribe abx for a infection symptoms?
3 days. Prescribe a 7 day course.
139
What causes double and blurred vison?
If the anesthetic is deposited too near the inferior rectus muscle or sympathetic innervation to the eye. Temporary and self-limiting. Patch the eye until vision returns.
140
When does facial nerve paralysis occur?
If local is injected into the parotid gland. Affects the facial nerve and there will be facial drooping and they won't be able to close their eyes.
In IA block: Needle directed too posteriorly. Need to contact bone.
In Ankinosi Nerve block: Needle over inserted.
141
What is the most common cause of needle breakage?
Sudden, unexpected movement of the patient.
Smaller gauge are more likely to break than larger ones.
Bending the needle also weakens the metal.
142
How do you avoid needle breakage?
Routinely use a 25-gauge needle. Try to not insert the needle to the hub.
143
What is the primary location of biotransformation or metabolism of amide-type local anesthetics?
Liver
144
What is the primary location of biotransformation or metabolism of ester-type local anesthetics?
Blood Plasma.
145
What is the action of all local anesthetic drugs in dentistry?
Vasodilators
146
Resting Plasma Epinephrine
18 micrograms?
147
What is the maximum safe dose of the vasoconstrictor epinephrine that can be administered in one setting to a normal healthy adult patient.
.2 mg or 200 micrograms.
148
What is an absolute contraindication for vasoconstrictors in patients?
Asthma.
149
What is the period of time a new impulse can be initiated, but only by a stronger than normal stimulus. Its followed by the Relative Refractory Period?
Absolute Refractory Period.
150
What is the amount of epi in 1 cartridge of 2% lidocaine 1:100,000 epinephrine?
0.018 mg.
151
What is the strongest/most potent vasoconstrictor concentration?
1:50,000.
152
What is a PDL injection also known as?
Intraligamentary injection
153
What is the vasoconstrictur that is most likely to cause tissue necrosis when administered as a palatal injection?
Norepinephrine.
154
What local anesthetic agent is considered less toxic because it is biotransformed by the liver, lung and kidney?
Prilocaine.
