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SP18: Local Anesthesia > Midterm > Flashcards

Flashcards in Midterm Deck (83):
1

T/F: The sodium channel has two gates, one for activation, and one for inactivation.

True

Initial depolarization widens the channel, opening the activation gate

Inactivation gate closes and allows the channel to reset - refractory period

2

What is the local anesthetic mode of action?

Block the influence of stimulation (depolarization) on Na+ permeability

3

What is the specific receptor theory of nerve blockade?

Anesthetic agent accesses and blocks channel from the intracellular side

Charged agents only block stimulated nerves

4

What is a phasic block?

Means only stimulated nerves are blocked

5

What are the three parts to the chemical structure of local anesthetic?

1. Aromatic group (hydrophobic)
2. Intermediate chain (amide or ester)
3. Amino group (hydrophilic)

6

The aqueous distribution constant (Q) reflects the ability to penetrate hydrophobic tissue and correlates with the _________ of the LA.

duration

7

The dissociation constant (pKa) is the proportion of ionized to un-ionized molecules and correlates with the ___________ of the LA.

onset

8

In what order do are sensations affected by LA?

1. dull pain
2. warmth
3. cold
4. sharp pain
5. touch
6. pressure
7. proprioception

9

What is the normal pH of anesthetics?

4-6

10

T/F: Most anesthetic compounds come with a vasoconstrictor.

True

11

T/F: All local anesthetics are vasodilators.

True

This is why vasoconstrictors (epinephrine) are in the carps

12

T/F: Anesthetic that is bound to protein will have the strongest effect.

False

No effect

13

What are some conditions that will increase and decrease binding of LA to proteins?

Increase: MI, cancer, trauma, surgery, chronic pain

Decrease: Pregnancy, oral contraceptives, estrogen supplementation, acidosis, increasing dose

14

Unbound LA will distribute to the ______ first.

lungs

15

How long will it take unbound LA to distribute to the muscle?

15 minutes

16

__________ anesthetics are broken down by circulating plasma pseudocholinesterase.

Ester-type

17

___________ anesthetics are broken down by hepatic metabolism.

Amide-type anesthetics

18

What will be the systemic vascular effects at moderate concentration of LA?

Decreased HR, cardiac output, PVR

19

The more ____________ an anesthetic is, the greater the risk for cardiac toxicity.

lipophilic

20

What processes decrease under sympathetic stimulation?

Disestive and secretory actions

21

Alpha receptors stimulate __________ or smooth muscle in blood vessels.

contraction

22

_________ receptors are found in the heart and produce cardiac stimulation.

Beta-1

23

What will happen under activation of alpha-1, beta-1, and beta-2 receptors?

Alpha-1: increase blood pressure
Beta-1: Increase heart rate
Beta-2: Decrease blood pressure

24

Why is antioxidant found in the LA carp?

To protect the vasoconstrictor

25

Why is HCl or NaOH found in some carpules?

pH adjusting agent

26

What are the 4 major reasons for adding vasoconstrictor to the carp?

1. Hemostasis
2. Slow CV absorption -> lower toxicity risk
3. Stays where its put -> longer duration

27

What are the three types of sympathomimetic drugs (vasoconstrictors)?

1. Direct acting - directly on receptors
2. Indirect acting - use NE release
3. Mixed

28

T/F: Epinephrine is a direct acting sympathomimetic drug.

True

29

T/F: A 1:50,000 concentration of vasoconstrictor is more potent than a 1:100,000 concentration.

True

30

What is the volume of a carp?

1.7 ml

31

What is the maximum epinephrine dose for an ASA I patient per appointment? Patient with heart disease?

0.2 mg; 0.04 mg

32

T/F: The beta effects of epinephrine predominate.

True

33

Which antioxidant is added with epinephrine?

Sodium bisulfite

34

How many cartridges of 1:100,000 epinephrine can a patient with CV disease receive per appointment?

2 carps, 0.04 mg epi

35

If a patient is taking non-selective beta blockers what will be the effect of the VC?

Hypertension and bradycardia

Because cardiac changes will be blocked and alpha receptors will dominate

36

What could be an effect of VC taken with TCAs?

They will block reuptake of E and NE so effects will be exaggerated

37

What are the contraindications for using vasoconstrictors?

1. Severe CV disease (ASA IV)
2. Acute MI
3. Unstable angina
4. Cardiac dysrhythmias
5. Uncontrolled hyperthyroidism

38

What are some ways to deal with high stress patients?

1. Morning appt
2. Short wait
3. Nitrous oxide
4. Excellent LA
5. Short appt

39

T/F: Patients with a stable angina should be treated in a monitored setting.

False

Stable - be cautious with stress/epinephrine
Unstable - treat in monitored setting

40

How should a patient with controlled hypertension be treated?

Pressure should be monitored, should recheck 5 minutes after initial check

41

What are some ways to recognize uncontrolled hyperthyroidism?

Thin, heat intolerant, hyperdynamic, proptotic

42

When should dialysis patients be treated for dental problems?

The day after dialysis

43

T/F: Epinephrine should be avoided in cocaine abuse patients.

True

44

T/F: Patients taking tricyclic antidepressants or MAO inhibitors should have their BP monitored during treatment.

True

45

What are the four criteria for a syringe?

1. Provide aspiration
2. Durable, sterilizable
3. Inexpensive, light, simple
4. Wide variety of carps and needles

46

T/F: The higher the gauge, the thicker the needle.

False

Lower gauge = thicker

47

T/F: Cartilages should be stored in antiseptic to keep them clean.

False

Semi-permeable membrane - carps will get contaminated

48

T/F: Carps should be stored in a refrigerator.

False

Room temp

49

T/F: Both hands should be used to recap the needle after LA has been administered.

False

One handed "scoop" technique

50

What structures are innervated by the inferior alveolar nerve?

1. Mandibular teeth to the midline
2. Body of mandible
3. Buccal mucoperiosteum anterior to 1st molars

51

What structures are innervated by the long buccal nerve?

Buccal mucoperiosteum of mandibular molars

52

What structures are innervated by the lingual nerve?

1. Anterior 2/3rds of tongue and floor of mouth
2. Lingual mucoperiosteum

53

Where in the mouth is infiltration very difficult?

Posterior mandibular teeth

54

Where is the point of insertion when administering LA via infiltration?

Point of intersection between the long axis of the tooth and the mucobuccal fold

55

The point of entry for an IA block is _________ to the coronoid notch and ___________ to the pterygomandibular raphe.

medial; lateral

56

T/F: Bone should be contacted when giving an IA block.

True

57

Where should the barrel of the needle be resting when giving an IA block?

On the premolars opposite the side of injection

58

How much of the dental needle should be in the tissue during an IA block?

2/3 - 3/4 the length of the long needle

59

T/F: The needle tip will be slightly superior to the mandibular foramen during an IA block.

True

60

During an IA block, the needle penetrates the _________ muscle and enters the ______________ space.

buccinator; pterygomandibular

61

If you touch bone too early how should you shift your angulation?

Switch so you are coming from canine region

62

How do you block the lingual nerve?

After IA block, slightly withdraw the needle and inject

63

If you are working on a lateral incisor and the patient still feels pain after an IA block, what is the likely problem?

Cross innervation from contralateral IAN - do slight infiltration

64

Where is the point of insertion for a LB nerve block?

Mucous membrane distal and buccal to most distal molar tooth

65

What will be numb with a mental nerve block?

Both incisor teeth and buccal mucosa

66

What is the Gow-Gates technique?

A way to get a true complete mandibular block

Aiming for the lateral side of the condylar neck

Have patient open wide, insert needle just distal to maxillary 2nd molar from opposite corner of the mouth, touch bone, aspirate, deposit

67

What is the advantage of the Vazirani-Akinosi technique?

Closed mouth technique

68

What is a concern for patients with bleeding disorders?

Deep injections are contraindicated

69

What teeth are innervated by the PSA?

Maxillary molars except the MB root of the first molar

70

What teeth are innervated by the MSA?

Premolars and MB root of first molar

71

What teeth are innervated by the ASA?

Anterior teeth

72

What nerves innervate the buccal soft tissues of maxillary teeth?

PSA, MSA, ASA

73

What nerve innervates the lingual soft tissues of teeth in the maxilla?

Anterior: nasopalatine nerve
Posterior: Greater palatine nerve

74

T/F: The needle tip should be past the apex of the tooth for infiltration.

True

75

What is the poi for a PSA block?

Height of MB fold over the second molar

76

T/F: There will be bone contact during a PSA block.

False

Insert about 1/2 of long needle and dispense

77

What is a common injury during needle insertion?

Pterygoid plexus hematoma

78

Where is the poi for a MSA block?

MB fold over 2nd premolar

79

What block will anesthetize the ASA, MSA, and infraorbital nerve?

Infraorbital nerve block

80

What is the poi for a infraorbital nerve block?

Over 1st premolar, should touch roof of the foramen

81

What are two important points for palatal injections?

1. Use topical
2. Pressure for blanching

82

Where is the POI for a greater palatine nerve block?

Just anterior to the GP foramen, often distal to second molar

83

Where is the POI for a nasopalatine block?

Just lateral to the incisive papilla