Local Anesthesia Board Review Questions – Flashcards
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local anesthesia is the __
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reversible depression of peripheral nerve condition
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which of the following are characteristics of the "ideal" local anesthetic agents?
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absence of allergic reactions, absence of systemic reaction, long duration
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all local anesthetics produce vasodilation which __
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increases the rate of absorption
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the greatest percentage of local anesthetics can be found in the __ after absorption into the blood stream
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skeletal muscle
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amide local anesthetic agents are metabolized in the __
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liver
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which of the following is NOT an indication of CNS toxicity?
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unilateral numbness of the tongue
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the weakest vasoconstrictor used in dentistry is __
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levonordefrin
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sodium bisulfite is added to anesthetics with vasoconstriction to __
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prolong the shelf life of the solution
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in the US, local anesthetic cartridges contain a volume of __
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1.8ml
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you have just administered an IA injection. The patient experiences pain as you remove the needle. The most likely explanation is:
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there is a barb on the end of the needle
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the greatest efficiency in aspirating is determined by __
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needle gauge
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what design feature of a syringe is necessary for a syringe to be an aspirating syringe?
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the harpoon
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prilocaine plain has a very __ toxicity
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low
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at high blood levels of local anesthetic, signs of cardiovascular overdose may include __
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depressed BP
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for patients with history of heart disease, the maximum number of cartridges of xylocaine 1:100,000 epic is __
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2
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Lidocaine __
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is the gold standard against which all new local anesthetics are measured
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of the following, the most frequent cause of needle breakage is __
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sudden unexpected patient movement
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psychogenic responsies __
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can be life threatening
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the most common psychogenic response is __
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vasodepressor syncope
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for which of the following injections would topical anesthetic be the LEAST effective?
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greater palatine
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as a rule, topical anesthetic agents __
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are used in greater concentration than injectable anesthetics
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dyclonine hydrochloride __
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has a long duration of action
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benzocaine, a topical anesthetic __
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is minimally absorbed
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which local anesthetic agent can limit the need for post surgical opioid analgesic agents?
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bupivacaine
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your patient has a history of cardiac disease. The cardiologist requests that you do not use a vasoconstrictor. Which local anesthetic agent would be the best choice for scaling and root planing this patient?
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3% mepivacaine
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Ester local anesthetics agents are metabolized in the blood by the enzyme __
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psuedocholinesterase
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local anesthetic cartridges should be __
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kept in their original container
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a __ needle is recommended for IA nerve blocks
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25 gauge long needle
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a __ needle is NOT recommended
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25 gauge long needle for PSA
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warming cartridges before use may lead to __
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patient discomfort
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topical nonbenzocaine anesthetics __
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are absorbed rapidly into the cardiovascular sysem
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Overdose =
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dose related
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allergic reaction =
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NOT dose related
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your patient has atypical pseudocholinesterase". How would this affect your decision to use LA?
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the patient would NOT be able to tolerate ESTER local anesthetics
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the dentist has administered 2 cartridges of 2% xylocaine with 1:50,000 epi. Within a few minutes, the patient complains of a throbbing headache and a rapid heart rate. He sweats profusely and becomes dizzy. The patient is experiencing __
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overdose to epinephrine
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you plan to scale and root plane the entire right side. You apply topical lidocaine ointment to 6 sites and then administer 4 cartridges of 3% mepivacaine. Immediately after the last injection, the patient loses consciousness and begins to convulse. The most likely cause is __
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local anesthetic overdose
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To reduce systemic complications associated with local anesthesia, __
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use the weakest effective concentration of anesthetic solution in the smallest effective dose
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amide local anesthetics are ___
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less likely than esters to cause allergic reactions
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post anesthetic oral lesions are caused by __
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an exacerbation of latent condition
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post injection facial nerve paralysis __
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blocks the corneal reflex
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post injection infection __
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may lead to trismus if not properly treated
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extruded stoppers in anesthetic cartridges indicate that __
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the anesthetic has been frozen
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the weakest part of the dental needle is __
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the junction of the hub and needle
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the most likely causes of an overdose from a local anesthetic:
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solution administered too rapidly solution administered intravenously
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to effectively aspirate, the operator must retract the finger/ring piston
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1-2mm
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you have just administered 1 cartridge of lidocaine with 1:100,000 epic. The patient tells you after the injection that he experienced a burnin sensation during the injection. This is due to the __
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presence of vasoconstrictor
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what effect do vasoconstrictors have on LA solutions?
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Lower the pH of the anesthetic solution
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which of the following factors should be considered when selecting a LA agent for your patient?
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- the length of time that you anticipate you will require pain control - the potential for your patient to have discomfort post treatment - the possibility that your patient may accidentally self-mutilate themselves - the medial status of the patient
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what is the absolute MRD of 2% lidocaine 1:100,000 epic for a medically compromised cardiac patient?
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2 cartridges
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the only LA agent that is a vasoconstrictor is __
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cocaine
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trismus is most often caused by __
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multiple injections in the same site
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which cranial nerve provides sensory innervation to the periodontium of the maxillary teeth?
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trigeminal
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if you are scaling and root planing teeth 2-5, which injections would you use?
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PSA, MSA, GP
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after administering a left IA injection, the patient complains of tooth 24 still being sensitive. What is the likely reason for this?
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cross-over innervation by the right incisive nerve
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the nerve that produces innervations to the gingival tissues of tooth 18 is __
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buccal (long buccal)
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name the nerve that provides sensory innervations to the gingival tissues of teeth 7-10
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ASA
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the anatomical landmark to determine the penetration site to anesthetize teeth 6-8 is:
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mucobuccal fold
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the nerve that provides innervations to the lingual gingiva of teeth 20 and 21 is __
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lingual
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name the nerve that provides innervation to the pulp of tooth 15:
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PSA
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comparing the speed of a nerve impulse traveling to the brain, which of the following statements is true?
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impulse travels faster in a myelinated nerve
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the generation of a nerve impulse follows which sequence?
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slow depolarization, rapid depolarization, and repolarization
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depolarization occurs as a result of __
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sodium ions moving inside a nerve cell
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the coronoid notch is the anatomical landmark for which injection?
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IA
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if the patient reports tingling of the lower lip, what nerve is losing sensation?
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mental
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the hamulus and retromolar triangle are landmarks for which structure?
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ptyergomandibular raphe
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where is axoplasm located?
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inside of nerve cell
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a pain stimulus acts on what part of the nerve?
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dendritic zone
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you are doing a left IA nerve block. What needle would you use?
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25 gauge long
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the maxillary division of the trigeminal nerve is __
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sensory only
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when do you aspirate?
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before deposition of solution
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infiltration is not as effective in the mandible compared to the maxilla because __
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mandibular cortical bone is denser
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the process of salutatory nerve conduction __
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- produces faster impulse propagation - is due to nodes of Ranvier - involves the leaping of impulse
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the purpose of aspiration is to:
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determine the needle is not in blood vessel
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you are scaling and root planing the mandibular right quadrant which includes the teeth 25-27, 29, 31. Which injections should you use?
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IA, long buccal, mental
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the ideal rate of solution deposition of atraumatic injections is:
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1 cartridge in 1 minute
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the importance of contacting bone during the IA block injection is the prevent:
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injecting into parotid gland
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after administering a left IA nerve block, your patients left eyelid starts to droop. What has occurred?
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facial nerve is anesthetized the needle was inserted too deep
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what is the deposition site for the IA nerve block?
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slightly superior to mandibular foramen
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pressure anesthetics is recommended for which injections?
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GP and NP
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faulty technique and __ are the most common reasons for failure to achieve adequate anesthesia
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patients anatomical variations
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your patient complains of burning as you deposit the solution. You can minimize burning by __
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depositing the solution more slowly
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which injection has the highest rate of positive aspiration?
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IA
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5 minutes ago, you administered a PSA injection and now your patient says his lower lip is tingling. What is likely the reason?
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needle not angled enough posteriorly
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after administering an IA nerve block, your patient still complains of sensitivity of tooth 30. The other teeth have adequate anesthesia. The likely reason for this sensitivity is:
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accessory innervations by mylohyoid
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numbness of the anterior 2/3 of the tongue is due to which nerve been anesthetized?
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lingual
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how far do you insert the needle for the IA nerve block?
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2/3 the needle length
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what sensation is lost first when local anesthetist is used?
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pain
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the patient complains of an electric shock sensation when you administer an IA block. This is likely due by __
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contacting nerve sheath
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depolarization is the result of __
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changes in permeability of nerve membrane influx of sodium ions into axoplasm
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local anesthesia works by:
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- binding receptor sites in sodium channels - preventing depolarization from occuring
