T5 Ch 9 & 10 Flashcards
The following are characteristics of the ideal local anesthetic except:
a. Sterilization by autoclave
b. Slow onset
c. Reversible
d. Absence of local reactions
b. Slow onset
Local anesthetics block the conduction of nerve impulses by decreasing the permeability of the nerve cell membrane to
a. Potassium ions
b. Sodium ions
c. fat soluble ions
d. cations
b. Sodium ions
In the presence of an acidic environment, such as infection or inflammation, the amount of free base is reduced; therefore __________ of the local anesthetic is in the ionized form, making anesthesia __________ difficult.
a. More, more
b. More, less
c. Less, more
d. Less, less
a. More, more
Reducing the rate of systemic absorption of a local anesthetic is important when it is used in dentistry because:
a. Otherwise, too large an area would be anesthetized.
b. If not, the anesthesia would not last long enough to complete a dental procedure.
c. The chance of systemic toxicity is reduced.
d. Local anesthesia is associated with respiratory depression.
c. The chance of systemic toxicity is reduced.
Addition of vasoconstrictor to local anesthetic (1) reduces blood supply to the area, (2) increases blood supply to the area, (3) limits systemic absorption, (4) increases systemic absorption, (5) reduces systemic toxicity, (6) increases systemic toxicity. Which of the three pairs of choices is correct?
a. 1, 3, 5
b. 1, 4, 5
c. 2, 3, 5
d. 2, 3, 6
e. 2, 4, 6
a. 1, 3, 5
Local anesthetics cross:
a. The placenta and blood-brain barrier
b. The placenta but not the blood-brain barrier
c. The blood-brain barrier but not the placenta
d. Neither the placenta nor the blood-brain barrier
a. The placenta and blood-brain barrier
Amide local anesthetics are metabolized:
a. By being hydrolyzed by plasma pseudocholinesterases
b. Primarily by the liver
c. In the spleen
d. Minimally and are excreted virtually unchanged
b. Primarily by the liver
Which nerve function is usually the first to be lost?
a. Touch
b. Warmth
c. Pressure
d. Autonomic
e. Pain
d. Autonomic
The maximal safe dose of lidocaine 2% with 1:100,000 epinephrine is approximately __________ cartridges.
a. 3
b. 6.5
c. 8.5
d. 11.5
c. 8.5
Which of the following local anesthetics is safest to use for dental treatment for a pregnant woman?
a. Mepivacaine
b. Lidocaine
c. Articaine
d. Bupivacaine
b. Lidocaine
Epinephrine is combined with local anesthetics so as to:
a. Enhance absorption
b. Prolong duration
c. Delay onset
d. Increase potency
b. Prolong duration
Lidocaine with epinephrine 1:100,000 provides a __________ duration of pulpal anesthesia.
a. 30-minute
b. 30- to 60-minute
c. 60- to 90-minute
d. 90-minute or more
c. 60- to 90-minute
Which of the following statements is true of mepivacaine?
a. Cross-allergenicity has been demonstrated between mepivacaine and other currently available amides.
b. Mepivacaine is effective topically.
c. Mepivacaine can be used as a 3% solution without a vasoconstrictor.
d. The benefit of a shorter duration of anesthesia warrants eliminating the vasoconstrictor.
c. Mepivacaine can be used as a 3% solution without a vasoconstrictor.
Which of the following local anesthetics has the longest duration of action?
a. Lidocaine
b. Mepivacaine
c. Prilocaine
d. Bupivacaine
d. Bupivacaine
Plain anesthetics without vasoconstrictor will exhibit a__________ duration of action and result in a __________ buildup of a systemic blood level.
a. Shorter, less-rapid
b. Shorter, more-rapid
c. Longer, less-rapid
d. Longer, more-rapid
b. Shorter, more-rapid