Alkadhi's Local Anesthetics

1. Which of the following is an advantage of using epinephrine with local anesthetics?

Limits toxicity

Increases concentration of local anesthetic by preventing its metabolism by the liver

Causes tissue edema

May lead to hypoxia and tissue damage

Prevents hypotension

2. The proposed mechanism of action of local anesthetics is:

Blocking K+ channels

Blocking Ca++ channels

Blocking release of NE

Blocking the extracellular part of Na channels

Blocking the intracellular part of Na channels

3. Which of the following characteristics is true for local anesthetics?

Molecule has to be lipid soluble to exert its Na channel blocking effect

Some topical local anesthetics can be absorbed systemically and can cause toxicity

The blocking effect of local anesthetics is gone when the molecule is in the cationic form

Entry of local anesthetics in the brain results in CNS depression initially followed by CNS stimulation

Cocaine also has anti-arrhythmic properties

4. All of the following are clinical uses for local anesthetics except:

Antiarrhytmic

Therapeutic nerve block and field block

Stimulant, euphoriant

Anticonvulsant in status epilepticus

None of these. All of the above are clinical uses for local anesthetics

5. Which of the following is true regarding local anesthetics?

Given with a vasodilator to increase duration of action

Thicker nerve fibers are more sensitive to local anesthetics than thinner ones

The more negative the membrane potential, the greater the degree of Na channel block

An active nerve is more sensitive to local anesthetics than a resting nerve

Local anesthetics alter Na and K permeability in neurons

6. Which of the following is not an adverse effect associated with local anesthetics?

Initial stimulation and then depression of CNS pathways

Local necrosis from vasoconstrictor actions

Blockage of muscarinic ACh receptors at high concentrations

Urticarial rashes

Decreased electrical excitability in myocardium

7. Toxic effects of cocaine include all of the following except

Tonic-clonic convulsion

Severe bruxism

Respiratory depression followed by stimulation

Pseudohallucinations

Formication

8. Which of the following is true with regards to local anesthetics?

Procaine is faster and longer lasting than lidocaine

Cocaine is good for topical anesthesia of upper respiratory tract

Bupivacaine and cocaine are the only natural anesthetic products

Procaine is hydrolyzed in vivo to GABA

Lidocaine is very lipid soluble

9. Place the following sensory modalities in the order in which they are affected by local anesthetics (first to last)
1. Pressure2. Temperature3. Motor function4. Pain5. Touch

1, 5, 4, 2, 3

4, 5, 2, 1, 3

4, 2, 5, 1, 3

4, 2, 1, 5, 3

3, 1, 5, 2, 4