Local Anesthetics (Msq Drill 178)

2. In order for anesthetics to work they have to block the action potential. How do they do this?

By blocking pottassium channels

By blocking sodium channels

By blocking release of acetylcholine from the presynaptic neuron

By blocking chloride channels

3. If you block calcium channels because of a high concentration of a local anesthetic you will have increased or decreased conduction?

Increased conduction

Decreased conduction

10. Which anesthetics should be used for a long procedure?

Water soluble

Lipophilic

Water soluble anesthetics have a shorter duration.

Explanation

Water soluble anesthetics have a shorter duration.

11. Would you use procaine for a long or a short procedure?

Long procedure

Short procedure

Because it is hydrophilic and therefore has a shorter duration of action.

Explanation

Because it is hydrophilic and therefore has a shorter duration of action.

12. In other words a low dose of a local anesthetic can block sodium channels, and lead to hyper or hypo excitalbility of cardiac muscle?

Hyper excitability

Hypo excitability

13. Which of the following is a sodium channel blocker that also inhibits the reuptake of dopamine and norepi?

Heroin

Cannabis

Coccaine

Methamphetamine

14.
You should use epinephrine in distal, perfusion limited sites such as the tip on of the nose, toes and fingers. True or false?

True

False

You should NEVER use epinephrine in perfusion limited areas.

Explanation

You should NEVER use epinephrine in perfusion limited areas.

17. Which local anesthetics are structurally and immunologically related to p-aminobenzoic acid (PABA?)

Esters

Amides

PABA is an intermediate in the bacterial synthesis of
folate. Sulfonamide drugs are structurally similar to PABA, and their antibacterial activity is due to their ability to interfere with the conversion of PABA to folate by the enzyme dihydropteroate synthetase. Thus, bacterial growth is limited through folate deficiency without effect on human cells.

Explanation

PABA is an intermediate in the bacterial synthesis of
folate. Sulfonamide drugs are structurally similar to PABA, and their antibacterial activity is due to their ability to interfere with the conversion of PABA to folate by the enzyme dihydropteroate synthetase. Thus, bacterial growth is limited through folate deficiency without effect on human cells.

19. What are the two structural classes of local anesthetics?

Esters

Amines

Amides

Carboxylic acids

Purines

Submit

21. Esters are preferable for patients with hepatic dysfunction. What enzyme degrades esters?

Acetylcholinestarase

Mono amine oxidase

Plasma cholinesterase

Synaptic cholinesterase

22. Calcium channels are blocked by a high conentration of a local anesthetics resulting in decreased conduction. Would this lead to high or low blood pressure?

High blood pressure - hypertension

Low blood pressure - hypotension

24. If you add epinephrine to a local anesthetic, does this increase or decrease absorption?

Increases absorption of local anesthetic

Decreases absoption of local anesthetic

25. All local anesthetics are __________ connected to an aromatic ring.

Weak acids

Strong acids

Weak bases

Stog bases

27. If oxidation of Fe2+ occurs as a result of a local anesthetics what will happen to the patient's respiratory status?

Shortness of breath

Hypoventiation

No change in respiratory status

28. Death is most definitiely resultant of a high concentration of a local anesthetic, what about nystagmus, do you need a high or a low concentration?

Nystagmus occurs at high concentrations

Nystagmus occurs at low concentrations

30. Oxdiation of FE2t to Fe3t with eventual cyanosis as a result of a local anesthetic will lead to cyanosis and shortness of breath. This can also be referred to:

Chocolate blood

Thick blood

Thin blood

Black blood

32. Local anesthetics can cause cyanosis due to the oxidation of Fe2+ to Fe3+. What is this process all known as?

Methylhemoglobinemia

Methomoglobinemia

Methylmyoglobiuria

33. If sodium channels are blocked because of a LOW concentration of a local anesthetic the cardiac tissue will experience increased or decreased automaticity?

Increased automaticity

Decreased automaticity

34. So if someone has taken coccaine and they are thus euphoric which of the following may you observe?

CNS depression

CNS stimulation

Bradycardia

Tachycardia

Hypertension

The hypertension is from an increased level of dopamine and norepi because of the reduced reuptake.

Explanation

The hypertension is from an increased level of dopamine and norepi because of the reduced reuptake.

Submit

35. In terms of cardiovascular side effects, what channels are blocked when a high concentration of local anesthetics is administered?

Sodium channels

Calcium channels

Pottasium channels

Chloride channels

36. A dose >10mg/kg of procaine is being prepared to be administered on patient. You walk in and state the following:

The patient will becone cyanotic because of the oxidation of hemoglobin

The patient will become cyanotic because of the oxidation of myoglobin

The patient will becone cyanotic because of the oxidation of iron Fe2+

The patient will become cynotic because of the reduction of Fe3+

37. A patient who has received an local anesthetic complains of a metallic taste in their mouth and a feeling of numbness around their mouth (cirumoral numbing). Are these symptoms reflective of a high or a low concentration of the local anesthetic?

High dose

Low dose