Midterm Flashcards Preview

Pain & Anxiety > Midterm > Flashcards

Flashcards in Midterm Deck (161):
1

Peripheral Nerve Fiber Classification

​Which subtype of Type A fibers is efferent; muscle tone?

A(gamma)

2

How do you prevent Needle Breakage?

  • use 25 g or 27 g needles
  • Use long - 32mm needle for IA block 

3

What are the 2 Needle lengths used in Dentistry?

  1. Long - 32 mm
  2. Short - 20 mm

4

Peripheral Nerve Fiber Classification

​Which subtype of Type A fibers is afferent; proprioception, touch, pressure?

Type A(beta)

5

What effect does Sodium bisulfite have on the LA?

  • decrease solution pH = more acidic = delayed onset

6

What is the relative refractory period due to?

hyperpolarization before RMP is established 

7

Peripheral Nerve Fiber Classification

​Which subtype of Type A fibers is, the largest; fastest; efferent; muscle movement?

A(alpha)

8

What are the 2 causes of Facial Paralysis?

  1. LA deposited in parotid gland
  2. bone not contacted during mandibular block

9

What LA is not used for hemostasis?

Mepivacaine

10

What is the MRD per appointment for Mepivacaine?

Adult = 400mg Child = 300mg

11

What type of LA should you select if you need hemostasis?

  • Epi ONLY (no levonordefrin)
  • 1:50,000 best 
    • 1:100,000 is better than 1:200,000

12

What is the Tx of Paresthesia?

  • 3 wks to 3 months, possible 1 yr

13

Acceptable RR for an Adult?

12-20

14

What are the 3 causes of Edema?

  1. Trauma
  2. Contaminated Anesthetic
  3. Allergic rxn to LA/sodium bisulfite

15

What is the absolute refractory period due to?

inactivation of Na+ channels during repolarization

16

What is the onset time of Bupivacaine?

5-10 mins

17

What are the symptoms of Allergic Reactions?

  • Delayed Hypersensitivity = rash; itching
  • Immediate Hypersensitivity = anaphylaxis

18

What length of needle is ALWAYS required for a Mandibular Block?

Long - 32mm

19

What concentration of Cetacaine is used?

  • 14% Benzocaine
  • 2% Butamben
  • 2% Tetracaine

20

What is the mechanism of action of Topical Anesthetics?

  • dec Na+ ion permeability = dec depolarization = blocks nerve impulse

21

Relative Contraindications of LAs (6)

  1. H2-receptor blockers
  2. Beta Blockers
  3. CNS Depressants 
  4. Pregnancy 
  5. Significant Liver Ds
  6. Renal Dysfunction 

22

How do you prevent a Hematoma?

  • Use 27g short - 20mm needle for PSA

23

What effect does a Vasoconstrictor in LA have on Duration = Potency?

dec BF = inc Duration = inc Potency 

24

Acceptable HR for a Child?

75-100

25

What is the MRD per appointment for Bupivacaine?

Adult = 90mg Child = 90mg

26

What is the onset time for Lidocaine?

2-3 mins

27

What Amide LA's are metabolized in the Liver ONLY (inc toxicity in liver ds)?

  • Lidocaine
  • Mepivacaine
  • Bupivacaine

28

What 3 factors affect the duraction of LA = Potency?

  1. Protein binding of specific LA
  2. Vascularity of injection site
  3. Vasoconstrictor in LA

29

Peripheral Nerve Fiber Classification

  • Largest fibers = fastest impulse conduction
  • Myelinated
  • Afferent or Efferent

Type A Fibers

30

What is the weakest part of the needle?

Hub + Needle Adaptor (1 piece)

31

What size of nerve fibers are MORE sensitive to LAs?

Small diameter

32

Which Amide is the most potent vasodilator?

Bupivacaine

33

What is the effect of inc protein binding of molecules on LA?

inc duration

34

What are the symptoms of Syncope?

  • Sweating; nausea, pallor
  • inc HR and inc RR

35

What is the duration of topical lidocaine?

15-45 min

36

What vasoconstrictor should be used if the pt is taking tricyclic anti-depressants?

  • 0.04mg Epi
  • No Levo

37

Peripheral Nerve Fiber Classification

​Which subtype of Type A fibers is afferent; PAIN; temperature?

A(delta)

38

What is the duration of action of 4% Prilocaine 1:200,000 epi?

60-90 mins

39

What LA is a good choice for readministration, CV ds, and Liver ds pts?

Articaine

40

What is a good choice if a vasoconstrictor is contraindicated?

Mepivacaine

41

What Amide LA's are metabolized in Liver + Lungs (shorter 1/2 life due to lungs)?

Prilocaine 

42

What causes the rapid onset of Nitrous Sedation?

low solubility in blood

43

What Pregnancy Category is Mepivacaine, and is it safe for lactation?

  • Category C
  • Lactation Safe

44

What is the duration of Cetacaine?

30-60 min

45

How do LA's stabilize the membrane?

Decreases the rate of depolarization; membrane remains polarized

46

What is another name for Benzocaine?

Hurricaine

47

What is the most common cause of a Hematoma?

  • Entering the venous Pterygoid Plexus when giving a PSA block

Remember to use a short 20mm, 27g needle @ 45 angles to long axis of tooth and to alveolar bone 

48

Is Cetacaine and Ester or Amide?

Ester

49

Which LA is the best choice for long tx and post-op pain control?

Bupivacaine

50

What is the MRD per appointment for Prilocaine?

Adult = 400mg Child = 400 mg

51

What size of nerve fibers require MORE volume of LAs?

Large diameter

52

What Topical Anesthetic is a good choice for thoose allergic to esters?

Lidocaine

53

What is the active form of the drug that canNOT cross the membrane?

  • RNH+ = cations (acid)

54

Amide LA's are combined with an acid to form what?

HCl Salt = water soluble = stable injectable solution

55

What is the Tx of Trismus?

  • 2-3 days
  • moist heat (20 min on/ 20 min off)

56

What are the symptoms of Epi Overdose?

  • Fight or Flight response - lasts 5-10 mins

57

What is the primary factor associated with the Induction (diffusion of molecules across membrane) of LA's?

  • Initial concentration 
    • inc conc = inc diffusion = rapid onset 

58

How does an inc pKa = inc cations = dec base affect the diffusion across the membrane?

Slower onset = slow diffusions 

59

What LA's are Long-Acting (90min or > pulpal anesthesia)?

  • 0.5% Bupivacaine 1:200,000

60

What is the Tx for Allergic Rxns?

  • Delayed = antihistamine, and document
  • Immediate life-threatening Anaphylaxis
    • Stabilize pt
    • Activate EMS
    • Document 

61

What level of LA's shows initial CNS Stimulation (inc HR, RR, and BP, muscle twitching, tremors)?

Moderate Overdose of LA's

62

What is the Tx for Epi Overdose?

  • Healthy Pts = reassure
  • CV Pts = prepare for medical emergency

63

What is the duration of action of Prilocaine without epi (4% Prilocaine Plain)?

40-60 mins

64

What is the tx for Hematoma?

  • Apply ice/pressure immediately 
  • inform pt of swelling/discoloration 7-14 days

65

What is the primary excretory organ for all LA's?

Kidney 

66

What is the Tx for Infection?

  • Antibiotics after 3 days

67

What level of LA's shows CNS Depression, due to vasodilation (dec HR, RR, and BP, convulsions, unconsciousness, progresses to resp arrest)?

High Overdose of LA's

68

What Pregnancy Category is Articaine, and is lactation safe?

  • Category B
  • Unknow Lactation Safety

69

How much nerve length must an LA penetrate to block a nerve impulse?

8-10mm (3-4 nodes of Ranvier)

70

At what BP range should you retake; refer for med consult before tx?

160-199/95-114

71

What pregancy category is Bupivacaine, and is it safe for lactation?

  • Category C
  • Unknown Lactation Safety 

72

In the reinjection of LA, if nerve fibers are fully recovered (no numbness) what occurs?

Tachyphylaxis = tolerance to LA = LA is ineffective

73

Which LA's are effective topicals?

  • Lidocaine 
  • Prilocaine

74

LA's provide what between the source of impulse and the brain so that the impulse never reaches the brain?

Chemical Block

75

Peripheral Nerve Fiber Classification

  • Smallest & unmyelinated
  • Most numerous
  • Afferent & Efferent
  • Post-ganglionic ANS; temperature; PAIN
    • Dull, achy pain

Type C Fibers

76

Other name for Lidocaine

Xylocaine

77

How does a dec pKa = inc anions = inc base, affect the diffusion across the membrane?

Rapid onset = fast diffusion 

78

What do Type A fibers require more of?

MORE anesthetic Volume

79

What are the 3 common Topical Anesthetics used in Dentistry?

  1. Benzocaine
  2. Lidocaine
  3. Cetacaine (Benzocaine + Butamben + Tetracaine)

80

What needle is used for Greater Palatine Blocks, and how are they performed?

  • 27g needle
  • insertion until bevel is buried ~1/4''
  • Use 1/4 carpule = 0.25cc or until tissue blanches

81

What is the onset time for Prilocaine?

2 mins

82

What is the duration of action of Mepivacaine without epi (3% Mepivacaine)?

20-40 mins

83

What is the onset time of Mepivacaine?

1.5-2 mins

84

What effect does stronger protein binding have on the duration = potency of specifc LA?

stronger binding = inc Duration = inc Potency 

85

What Amide LA's are metabolized 90% in Plasma and 10% in Liver?

Articaine

86

What is the affect of inc vasodilation of LA?

dec potency + dec duration = inc dose needed

87

What are the primary and secondary factors associated with the Onset of Action of LA's?

  • dec pKa = rapid onset
  • small diameter nerves = rapid onset 

88

What is the duration of action of 2% Mepivacaine 1:20,000 levo?

60 mins

89

What 5 things are included in the contents of the carpule?

  1. LA durg
  2. Sodium hydroxide
  3. Sodium chloride
  4. Vasocontriction = Epi or Levonordefrin
  5. Vasoconstrictor preservative = Sodium bisulfite (allergic rxns)

90

What concentration of Benzocaine is most commonly used?

20%

91

What are the 4 causes of Paresthesia?

  1. Trauma to nerve sheath (pt feels a "shock")
  2. Edema/hemorrhage near nerve
  3. Contaminated Anesthetic 
  4. Possible association with Articaine

92

If nerve fibers are only partially recovered (pt still numb) for the Reinjection of LA what would be effective?

Small volume is effective with Rapid Onset

93

3 Causes of EPi Overdose?

  1. 1:50,000 concentration
  2. Intravascular injection
  3. CV pts 

94

How far into the tissue should the needle be for a mandibular block?

  • 1 inch
  • 2/3 to 3/4 length of long -32mm needle

95

What is the primary factor for the Recovery from LA Block (reversal of LA action)?

Degree of binding to receptor site 

96

What are the symptoms of LA Overdose?

  • Low Overdose = CNS Excitation 
  • Higher Overdose = CNS and CV Depression

97

What 4 factors increase Absorption of LA (inc risk of systemic toxicity)?

  1. Total Dose Administed (inc dose)
  2. LA concentration (inc conc)
  3. Route of Admin (topical)
  4. Vascularity of Admin site (intravascular injection)

98

Acceptable RR for a Child?

18-30

99

In Topical Anesthetics there is an association between Benzocaine Sprays and what?

Methemoglobinemia

100

In the Depolarization of the Membrane, what does the threshold (+15-20mV) stimulus trigger?

  • Ca+ & Na+ ion channels to open
  • Na+ ions flow INTO neuron = inside becomes + charged

101

At what BP range should you consider N2O for stress reduction?

140-159/90-94

102

Other name for Mepivacaine

Carbocaine

103

What are the 5 Absolute Contraindications for Nitrous Oxide Sedation?

  1. Nasal Obstruction
  2. Vit B12 Def
  3. Alcoholic/Recovering Addict
  4. Uncommunicative
  5. Patient Refusal

104

What LA's are Short-Acting (30 min pulpal anesthesia)?

  • 3% Mepivacaine - plain
  • 4% Prilocaine - plain

105

What are the Topical Ester LA's?

  • Benzocaine
  • Tetracaine
  • Procaine

106

What is the duration of action of 4% Articaine 1:200,00 epi?

45-60 mins

107

Other name for Prilocaine

Citanest

108

What LA should be used for pts with Significant Liver Ds?

Articaine

109

What is the effect of Infection of LA's?

Inadequate Anesthesia

110

What LA has the shortest half life?

Articaine

111

What is the onset of Topical Lidocaine?

2-10 min

112

Is Benzocaine and Ester or Amide?

Ester

 

113

What is the effect of increased concentration of LA?

Inc diffusion through membrane = Rapid onset

114

What CV effects occur with a Mild Overdose of LA's?

slight inc BP, inc HR, inc RR

115

What is the Tx for Edema?

  • NONE
  • Resolves within 3-4 days

116

How do neurons maintain RMP polarization?

  1. Na/K Pump
  2. OPEN K+ channels
  3. CLOSED Na+ channels

117

Acceptable HR for a Toddler?

120-160

118

What is the inactive, lipid soluble form of the drug that crosses the membrane?

RN = anions (base)

119

What do Topical LA require?

  • Increased concentrations (needed to penetrate mucosa)
  • Increased Toxicity 

120

What level of LA's shows no CNS effects; may have anti-convulsant properties?

Low blood levels of LA's

121

What are the 3 causes of Allergic Rxns?

Hypersensitivity Rxn to:

  1. Methylparaben 
  2. Sodium bisulfite
  3. ester topical 

122

What Pregnancy Category is Lidocaine, and is it safe for lactation?

  • Category B
  • Lactation Safe

123

What is the cause of Syncope?

  • Drastic drop in BP
  • Emotional Response (to injection)

124

Peripheral Nerve Fiber Classification

  • Slightly myelinated
  • Efferent
  • Preganglionic ANS; vascular smooth muscle

Type B Fibers

125

What is the onset time for Articaine?

1-3 mins

126

Acceptable HR for an Adult?

60-100

127

What is the duration of Benzocaine?

5-15 mins

128

Prior to 1984 what was added to LA solutions without Epi?

Methylparaben (allergy)

129

Overdose of vasoconstrictors usually occurs via

Intravascular injection

130

What is the duration of action of 0.5% Bupivacaine 1:200,000 epi?

1.5-3 hrs

131

What factor decreases absorption of LA?

increased vasoconstrictor

132

What is the effect of increased Lipid solubility on LA's?

  • inc Potency = dec dose needed
  • inc diffusion through membrane = Rapid onset

133

What is the MRD of Topical Lidocaine?

200 mg

134

What CV effects occur with a High Overdose of LA's?

CV Depression (dec HR, RR, and BP, slurred speach, disorientation, unconsciousness, progress to Cardiac Arrest)

135

What are the Absolute Contraindications to LA's?

Allergy

136

What LA is highly lipid soluble and has high diffusion through bone?

Articaine

137

What is the least toxic LA in dentistry?

Prilocaine

138

What are the 8 Absolute Contraindications for Vasoconstrictors?

  1. MI/Coronary Bypass surgery within 3-6 months
  2. Uncontrolled Hypertension
  3. Uncontrolled Angina Pectoris
  4. Uncontrolled Arrhythmias
  5. Uncontrolled Hyperthyroidism
  6. Sulfite allergy
  7. Glaucoma
  8. Cocaine/Meth Use

139

What is the MRD per appointment for Articaine?

Child = 500mg

140

What gauge needle is the safe choice in high risk areas?

25 g (large diameter) provides reliable aspiration

141

What is the MRD per appointment for Lidocaine?

Adult = 500mg Child = 300mg

142

How does LA prevent Na+ ions from moving inside the cell?

LA's bind to Na+ channels inside the cell, preventing them from opening

143

What LA is the best choice for pregnant and CV pts?

Prilocaine

144

Acceptable RR for a Toddler?

25-32

145

What are the 3 needle gauge sizes used for intraoral injections?

  1. 25 g
  2. 27 g
  3. 30 g

146

What LAs should be used if pregnant?

  • Prilocaine or Lidocaine

147

At what BP range should you retake; refer for immediate med consult?

>200/>115

148

What does Repolarization of the membrane begin with?

  • Movement of K+ ions to OUTSIDE
  • Na/K pump moves Na+ ions to OUTSIDE = restores RMP

149

What Pregnancy Category is Prilocaine, and is lactation safe?

  • Category B
  • Unknown Lactation Safety

150

What is the onset of Cetacaine?

30 sec

151

Other name for Bupivacaine

Marcaine

152

What is most commonly used in dentistry for nerve block?

Lidocaine

153

What CV effects occur with a Moderate Overdose of LA's?

initial CV Stimulation (inc HR, inc RR, inc RR, headache, lethargy)

154

  • Which LA is the most potent and most toxic LA used in dentistry
  • Highly lipid soluble and binds strongly 

Bupivacaine

155

What concentration of Topical Lidocaine is used?

2-5%

156

Other name for Articane

Septocaine

157

What are the 4 functions of Vasoconstrictors in LA's?

  1. Constrict bv's = dec Dose of LA
  2. inc Duration of LA x6
  3. Hemostatis
  4. dec Absorption rate of LA = dec risk of Toxicity 

158

What is the MRD of Cetacaine?

200 mg

159

What effect does an increased vascularity of the injection site have on the Duration = Potency of LA?

inc vascularity = dec Duration = dec Potency

160

What is the duration of action of 4% Articaine 1:100,00 epi?

60-75 mins

161

What is the onset of Benzocaine?

Rapid onset = 30sec - 2mins