1. Pharmacology -
Dentalelle Tutoring

2. Chapter 9

3. WHY IS EPI USED IN LOCAL ANESTHETICS?

4. PROLONG DURATION
Meaning..the local anesthetic lasts longer to ensure proper freezing of the tooth and tissues

5. WAS COCAINE USED AS AN ANESTHETIC?

6. YES..
..but not anymore! It was quickly recognized for its addicting properties.

7. WHAT ARE SOME EXAMPLES OF LOCAL ANESTHETICS USED TODAY?

8. The amide lidocaine (Xylocaine) was released in 1952
HISTORY
The amide lidocaine (Xylocaine) was released in 1952
mepivacaine (Carbocaine) was released in 1960
More recently, bupivacaine (Marcaine) has been made available for dental use

9. No local anesthetic in use today meets all THE NECESSARY requirements
TRUE OR FALSE…
No local anesthetic in use today meets all THE NECESSARY requirements

10. But…many acceptable agents are available
TRUE
But…many acceptable agents are available

11. IDEAL LOCAL ANESTHETIC PROPERTIES OF THE IDEAL LOCAL ANESTHETIC
potent local anaesthesia
reversible local anaesthesia
should be followed by complete recovery without evidence of structural or functional nerve damage
absence of adverse systemic effects & allergic reactions
rapid onset & good duration
should have moderate lipid solubility which allows an anesthetic agent to diffuse across lipid membranes of all peripheral nerves (motor, sensory, autonomic)
adequate tissue penetration
low cost
long shelf life (stability in solution)
ease of metabolism & excretion
FOR TEST KNOW THE PROPERTIES (BOX 9-1; PAGE 113)

12. WHAT ARE THE TWO GROUPS OF LOCAL ANESTHETICS?

13. Cross-hypersensitivity between amides and esters is unlikely

14. MECHANISM OF ACTION
ACTION OF NERVE FIBERS
A resting nerve fiber has a large number of positive ions on the outside and a large number of negative ions on the inside
The nerve action potential results in the opening of sodium channels and an inward flux of sodium (Na+)
This results in a change in potential
The outward flow of potassium (K+) ions repolarizes the membrane and closes the sodium channels

15. HOW DO LOCAL ANESTHETICS WORK?
IN RELATION TO NERVE IMPULSES?

16. DECREASING PERMEABILITY TO SODIUM IONS…
After combining with the receptor, local anesthetics block conduction of nerve impulses by decreasing the permeability of the nerve cell membrane to sodium ions

17. interferes with the function of the neurons
MECHANISM OF ACTION
Local anesthetics slows or blocks depolarization by reducing Na+ permeability into the nerve cytoplasm, thus inhibiting the flow of K+ out of the cell. ↓
interferes with the function of the neurons
prevents the propagation of action potential (the reproduction of nerve transmission)
prevents the onset of nerve conduction & blocks nerve impulse formation
ACTION OF NERVE FIBERS
SUMMARIZED
A SUMMARY

18. MECHANISM OF ACTION
The mechanism of local anesthetics involves action on Axons and Sodium channels
ACTION OF NERVE FIBERS
Propagation can refer to: Reproduction, and other forms of multiplication or increase
Local anesthetics bind to sodium channels found in the axons of nerves. They stop the propagation of the electrical impulse along the axon.

19. ARE LOCAL ANESTHETIC AGENTS WEAK OR STRONG BASES?

20. Therefore, the local anesthetic is a weak bases.
When the acidity of the tissue ↑, (as in instances of infection), the effect of a local anesthetic ↓
Therefore, the local anesthetic is a weak bases.

21. EG: Lidocaine’s pKa =7.9(Weak base drug)
Absorption & L.A.
local
anaesthetic
(L.A.)
L.A.
tooth
L.A.
EG: Lidocaine’s pKa =7.9(Weak base drug)
↓ pH
↑ ionization
↑ [H+]
L.A.
*Weak bases are better absorbed when the pH is greater than the pKa
REPEAT FROM CHAPTER 2 p 17
infection
In the presence of infection, there may be a reduced clinical effect of L.A. due to the ↓’d pH level. The infection site is more acidic and more ionized and less likely to absorb the L.A drug (weak base).

22. IF INFECTION IS PRESENT, HOW DOES THE LOCAL ANESTHETIC REACT?

23. IT IS HARDER TO FREEZE –LIKELY INFECTION MUST BE CLEARED BEFORE FREEZING IS DONE.
In the presence of an acidic environment, such as infection or inflammation, the amount of free base is reduced

24. WHAT DOES ADME STAND FOR?

25. VERY IMPORTANT!
Absorption
Distribution
Metabolism
Excretion

26. WHAT IS ABORPTION?

27. Absorption depends on its route
When injected into tissues the rate depends on the vascularity of the tissues

28. PHARMACOKINETICS
ABSORPTION
Reducing the rate of systemic absorption of a local anesthetic is important when it is used in dentistry because the chance of systemic toxicity is reduced.
A vasoconstrictor is often added to the local anesthetic to reduce the rate of absorption.

29. WHAT CAN BE ADDED TO REDUCE THE RATE OF ABSORPTION?

30. A VASOCONSTRICTOR

31. Addition of vasoconstrictor to local anesthetic:
PHARMACOKINETICS
ABSORPTION
Addition of vasoconstrictor to local anesthetic:
Reduces the blood supply to the area
so as to ↓ rate of diffusion of anaesthetic into the blood vessels
this also prolongs the duration & effectiveness of the desired action
decreases bleeding in the area
Limits systemic absorption
Reduces systemic toxicity

32. WHY IS REDUCING THE RATE OF ABSORPTION SO IMPORTANT?

33. REDUCES SYSTEMIC TOXICITY

34. WHAT IS DISTRUBUTION?

35. LOCAL ANESTHETIC DISTRUBUTED THROUGHOUT
Local anesthetics cross the placenta and blood-brain barrier

36. AMIDES: are metabolized primarily by the liver
PHARMACOKINETICS
METABOLISM
LA agents are metabolized differently, depending on whether they are amides or esters.
AMIDES: are metabolized primarily by the liver
In severe liver disease or with alcoholism, amides may accumulate and produce systemic toxicity
ESTERS: are hydrolyzed by plasma pseudocholinesterases and liver esterases

37. WHAT IS EXCRETION?

38. EXCRETED BY KIDNEYS
Metabolites and some unchanged drug of both esters and amides are excreted by the kidneys

39. WHAT NERVE DOES LOCAL ANESTHETIC BLOCK?

40. PERIPHERAL NERVE CONDUCTION
The main clinical effect of local anesthetic is reversible blockage of peripheral nerve conduction

41. COMMON ORDER OF NERVE FUNCTION LOSS
PHARMACOLOGIC EFFECTS
COMMON ORDER OF NERVE FUNCTION LOSS
Autonomic *is the most sensitive to inhibition by local anesthetic agents
Cold
Warmth
Pain
Touch
Pressure
Vibration
Proprioception
Motor
PERIPHERAL NERVE CONDUCTION (BLOCKER)
The order of loss of nerve function
Proprioception (pro-pree-o-ception): an unconscious perception of stimuli from within the body detected from nerve stilmuli
The order of nerve impulse return: opposite (reverse)

42. WHY ARE LOCAL ANESTHETICS SUCCESSFUL IN TREATING ARRHYTMIAS?

43. WHAT DO PLASMA LEVELS HAVE TO DO WITH LOCAL ANESTHETIC?

44. ADVERSE REACTIONS AND TOXICITY

45. ADVERSE REACTIONS
Although toxicity to local anesthetics is rare in the doses normally used in dentistry, patients can still suffer from a classic toxic reaction.

46. LOCAL ANESTHETIC TOXICITY causes stimulation of the CNS including:
ADVERSE REACTIONS
LOCAL ANESTHETIC TOXICITY
causes stimulation of the CNS including:
restlessness,
tremors
seizures
followed by CNS depression and coma.

47. HOW MANY CARPS ARE MAX FOR LIDOCAINE?

48. 8.5 CARPS

49. WHY WOULD A HEMATOMA BE PRODUCED?

50. POOR INJECTION TECHNIQUE OR EXCESSIVE VOLUME

51. WOULD COULD RESULT IN RIDIGITY OF MUSCLES?

52. MALIGNANT HYPOTHERMIA

53. MALIGNANT HYPERTHERMIA
ADVERSE REACTIONS
MALIGNANT HYPERTHERMIA
An autosomal dominant trait characterized by often fatal hyperthermia with rigidity of muscles occurring in affected people exposed to certain anaesthetic agents
particularly halothane & succinylcholine (G.A.’s)
NOT related to amides!
In the past, the belief was that the amide local anesthetics might precipitate malignant hyperthermia, but they are currently no longer implicated. Patients with a family history of malignant hyperthermia can be given amide local anesthetic agents.

54. IF A WOMAN IS PREGNANT AND ANESTHETIC MUST BE GIVEN…
..WHAT IS BEST?

55. LIDOCAINE

56. WHAT TYPE HAS A GREAT POTENTIAL FOR ALLERGY?
AMIDES OR ESTERS?

57. ESTERS

58. diphenhydramine (Benadryl)
ADVERSE REACTIONS
ALLERGY
IF A PATIENT REPORTS A HISTORY OF ALLERGIES TO ALL LOCAL ANESTHETIC AGENTS
Can use antihistamine
diphenhydramine (Benadryl)
as a local anesthetic
Antihistamines, because of their similarity in structure to local anesthetics, have some local anesthetic action
diphenhydramine (Benadryl) in a concentration of 1% plus 1:100,000 epinephrine is recommended to be given by injection to produce a block
No prepared product is available; this combination must be prepared from its constituents

59. WHICH INGREDIANT REDUCES BLEEDING?

60. VASOCONSTRICTORS

61. IF A PATIENT HAS ASTHMA, HOW MUST YOU BE CAREFUL?

62. ANTIOXIDANT IN LOCAL
The antioxidant for the vasoconstrictor may produce a hypersensitivity reaction that exhibits itself as an acute asthmatic attack

63. WHERE IS TOPICAL PLACED?

64. THE MUCOUS MEMBRANE OF THE SKIN

65. LOCAL ANESTHETIC AGENTS
Amides (Only class of anaesthetics used parenterally)
Lidocaine (Xylocaine)
Mepivacaine (Carbocaine)
prilocaine (Citanest; Citanest Forte)
bupivacaine (bu·piv·a·caine)
Esters (No esters are currently available in a dental cartridge)
procaine
propoxycaine
Tetracaine
Esters, such as benzocaine, are commonly used topically
**Esters are not used in dentistry as local anesthetics, but used topically.
eg. Benzocaine.

66. LOCAL ANESTHETIC AGENTS
SOME COMMON
LOCAL ANESTHETIC AGENTS
SEE NOTE
LA AGENT
NOTES
procaine
no longer used
lidocaine (Xylocaine)
most common used
least painful
can only use 100,000epi
mepivacaine (Carbocaine; Isocaine)
shortest duration
when no epi is needed.
bupivicaine (Marcaine)
Painful
longest duration 6-8 hours
articaine (Septocaine)
the most potent
prilocaine plain (Citanest)
Prilocaine epi (Citanest Forte)
similar to lidocaine
rapidly metabolized
FOR TESTING PURPOSES, WILL ONLY SEE THE GENERIC NAME MORE THAN THE BRAND NAMES – IF YOU SEE A BRAND NAME IT WILL BE BESIDE THE GENERIC NAME

67. WHAT IS THE MOST COMMON LA USED IN DENTISTRY?

68. LIDOCAINE 2% - (1: EPI)

69. LOCAL ANESTHETIC AGENTS (Carbocaine, Isocaine)
AMIDES
mepivacaine
(Carbocaine, Isocaine)
similar effectiveness as lidocaine
BUT is NOT effective topically.
produces LESS vasodilation than lidocaine therefore can be used as a 3% solution WITHOUT a vasoconstrictor.
BUT systemic toxicity more likely
Is combined with levonordefrin (not epinephrine) as the vasoconstrictor
usual dosage in dentistry: 2% solution with 1:20,000 levonordefrin
It can be used for SHORT procedures when a vasoconstrictor is contraindicated.
duration of action of about 30 minutes
TRUE STATEMENTS ABOUT MEPIVACAINE – KNOW FOR EXAM

70. Severeal cases of METHEMOGLOBINEMIA
LOCAL ANESTHETIC AGENTS
prilocaine
(Citanest, Citanest Forte)
Severeal cases of METHEMOGLOBINEMIA
(cyanosis of the lips & mucous membranes & occasionally respiratory & circulatory distress)
have been reported with use of prilocaine
should not be administered to patients in which problems with oxygenation may be critical
AMIDES

71. WHICH ONE HAS THE LONGEST DURATION OF ACTION?

72. MARCAINE

73. LOCAL ANESTHETIC AGENTS
buprivacaine
(Marcaine)
Has the longest duration of action.
major advantage  greatly prolonged duration of action.
indicated in lengthy dental procedures when pulpal anesthesia of greater than 1.5 hours is needed or when postoperative pain is expected.
Related to lidocaine & mepivacaine
More potent but less toxic than the other amides
Available in dental cartridges as a 0.5% solution with 1:200,000 epinephrine
AMIDES

74. WHAT IS BOTH AN ESTER AND AN AMIDE?

75. ARTICAINE

76. VASOCONSTRICTORS
OVERVIEW
The vasoconstrictors are members of the autonomic nervous system drugs called the
ADRENERGIC AGONISTS
or sympathomimetics.

77. NO vasoconstrictor means:
VASOCONSTRICTORS
OVERVIEW
NO vasoconstrictor means:
the anesthetic drug is more quickly removed from the injection site and distributed into systemic circulation than if the solution contained a vasoconstrictor
more likely to be toxic than those given without a vasoconstrictor

78. VASOCONSTRICTORS
OVERVIEW
Plain anesthetics without vasoconstrictor will exhibit a SHORTER duration of action and result in a MORE RAPID buildup of a systemic blood level.
Any advantage gained by eliminating the vasoconstrictor must be weighed against the potential for adverse effects from the epinephrine.

79. IF A CLIENT HAS UNCONTROLLED BLOOD PRESSURE – CAN LA BE GIVEN IN A CONTROLLED DOSE?

80. NO – IT IS BEST TO DELAY TREATMENT

81. A CARDIAC PATIENT can be given 2.0 CARTRIDGES of 1:100,000 epinephrine
VASOCONSTRICTORS
OVERVIEW
A CARDIAC PATIENT
can be given
2.0 CARTRIDGES of
1:100,000 epinephrine
without
exceeding the
cardiac dose.

82. WHAT IS THE MAXIMAL SAFE DOSE FOR A HEALTHY CLIENT?

83. 0.2 MG OF EPI
The maximal safe dose of epinephrine for the healthy patient is 0.2 mg and for the cardiac patient is 0.04 mg

84. SOME COMMON TOPICAL ANESTHETICS
TOPICAL AGENT
NOTES
Cocaine
highly effective
Not in use now
Benzocaine
The only use for the Ester
The most common used before LA
Lidocaine
commonly used before procedures
Tetracaine)
–solution/ointment

85. WHAT IS ORAQIX?

86. SOMETHING THE RDH CAN USE TO FREEZE THE GUMS

87. lidocaine & prilocaine (Injection-Free Anesthesia)
TOPICAL ANESTHETICS
lidocaine & prilocaine
(Injection-Free Anesthesia)
(Oraqix)
May be combined for injection-free local anesthesia.
The combination of Oraqix applied into the periodontal pocket offers pain relief during scaling and root planing procedures
Duration of action: approx. 20min.
The onset of action: approx. 30sec after application.
AMIDES

88. WHAT IS THE MOST COMMONLY USED TOPICAL?

89. BENZOCAINE

90. INSTRUCTIONS FOR PATIENTS RECEIVING LOCAL ANESTHETICS
Patients should be advised to tell you if they are feeling anxious, nervous, or if they are having heart palpitations.
Most of these symptoms can be avoided by lowering the dose or switching to another LA
Some LA may cause drowsiness
Patients should use caution if an opioid analgesic or antianxiety drug is also Rx
Avoid driving or doing anything that require thought or concentration
Have the patient avoid eating or drinking very hot or cold food or drink. The local anesthetic may make it difficult to detect temperature changes.

91. CHAPTER 10

92. CAN NITROUS OXIDE BE USED ALONE AS AN ANESTHETIC?

93. NO!

94. WHAT ARE THE STAGES/PLANES OF ANESTHESIA?

95. STAGES… Stage I – Analgesia Stage II – Delirium or Excitement
Stage III – Surgical Anaesthesia
Stage IV – Respiratory or Medullary Paralysis

96. STAGES AND PLANES OF ANESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE I – ANALGESIA
↓ sensation of pain
patient conscious and responsive
nitrous oxide in dental office is an example
end of this stage marked by loss of consciousness

97. STAGES AND PLANES OF ANESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE I – ANALGESIA
Nitrous oxide, as used in the dental office, maintains the patient in STAGE I
Is characterized by the development of analgesia or reduced sensation to pain.
The patient is conscious and can still respond to commands.
Reflexes are present, and respiration remains regular.
Some amnesia may also be present.

98. STAGES AND PLANES OF ANESTHESIA STAGE II – DELIRIUM OR EXCITEMENT
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE II – DELIRIUM OR EXCITEMENT
Begins with unconsciousness.
Involuntary movement & excitement.
Respiration becomes irregular, and muscle tone increases.
Sympathetic stimulation produces tachycardia, mydriasis, and hypertension (↑ BP).
Emesis (vomiting) and incontinence (defecation) can occur.

99. STAGES AND PLANES OF ANESTHESIA STAGE III – SURGICAL ANAESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE III – SURGICAL ANAESTHESIA
This is the stage in which most major surgery is performed
The loss of respiratory control (i.e., diminished carbon dioxide response, paralysis of intercostal muscles) first occurs during stage III
Paralysis of intercostal muscles begins in plane III and is complete in plane IV of stage III anesthesia.

100. STAGES AND PLANES OF ANESTHESIA STAGE III – SURGICAL ANAESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE III – SURGICAL ANAESTHESIA
Divided into four planes differentiated by eye movements, depth of respiration, muscle relaxation:
Plane I & II
return of REGULAR respiration, muscle relaxation and normal HR & pulse rate
Plane III
↓ skeletal muscle tone, dilated pupils, ↓ BP
Plane IV
characterized by intercostal muscle paralysis (diaphragmatic breathing remains) & absence of all reflexes
Muscles of respiration = intercostal muscle

101. STAGES AND PLANES OF ANESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
STAGE IV – RESPIRATORY OR MEDULLARY PARALYSIS
Characterized by complete cessation of respiration and circulatory failure.
Pupils are maximally dilated, and blood pressure falls rapidly.
If this stage is not reversed immediately, the patient will die.
Respiration must be artificially maintained.

102. STAGES AND PLANES OF ANESTHESIA
MECHANISM OF ACTION
STAGES AND PLANES OF ANESTHESIA
Stage I – Induction Period
Nitrous oxide, as used in the dental office, maintains the patient in STAGE I
Analgesia
Amnesia
Euphoria
consciousness
Stage II – Induction Period
Excitement
Delirium
combativeness
Stage III
Where most major surgery is performed
Divided into four planes
Surgical Anesthesia
Unconsciousness
Regular respiration
Decrease in eye movement
loss of respiratory control
Stage IV
Medullary Depression
Respiratory arrest
Cardiac depression and arrest
No eye movement
SUMMARY OF THE STAGES
INDUCTION Refers to quick change in the patient’s state of consciousness from stage I to stage III

103. FOR GENERAL ANESTHETICS – WHAT ARE TWO TYPES?

104. INHALATION AND INTRAVENOUS (IV)

105. REMEMBER..
The less soluble the anesthetic is in body tissues, the more rapid the onset and recovery.

106. CLASSIFICATION OF ANESTHETIC AGENTS
GENERAL ANESTHETICS
CLASSIFICATION OF ANESTHETIC AGENTS
PHYSICAL FACTORS
Nitrous oxide (NO2) =
Rapid onset and low solubility in blood
These physical factors allows the anesthesiologist to adjust quickly the desired level of anesthesia.
Whereas, Halothane = intermediate onset and higher solubility in blood.
Table 10-4 page 130 gives the physical properties of some of the anesthetics

107. WHAT IS MAC?

108. MINIMAL ALVEOLAR CONCENTRATION
The term minimal alveolar concentration (MAC) is used to compare potency of general anesthetic inhalation agents
MAC is the defined as the minimum alveolar concentration of anesthetic at 1 atmosphere required to prevent 50% of patients from responding to a supramaximal surgical stimulus

109. CLASSIFICATION OF ANESTHETIC AGENTS
GENERAL ANESTHETICS
CLASSIFICATION OF ANESTHETIC AGENTS
PHYSICAL FACTORS
Of the following general anesthetic agents NITROUS OXIDE has the largest MAC value
MAC of:
nitrous oxide > 100;
halothane 0.75,
enflurane of 1.68.
isoflurane is 1.15
Lower MAC values indicate a more potent anesthetic

110. WHAT IS NITROUS OXIDE?

111. COLORLESS AND ODOURLESS GAS
Antianxiety agent + analgesic agent

112. WHAT IS BALANCED ANESTHESIA?

113. COMBINATION OF…
Rapidly acting IV agent + N2O-O2 (nitrous oxide & oxygen) combination + volatile anaesthetic = balanced anaesthesia

114. WHY IS NITROUS OXIDE NOT GOOD TO USE AS A GENERAL ANESTHETIC ALONE?

115. MAC > 100
Because of its low potency (MAC > 100), it is unsatisfactory as a general anesthetic when used alone
If, however, anesthesia is first induced with a rapidly acting IV agent and N2O/O2 is administered in combination with a volatile anesthetic, excellent balanced anesthesia is produced

116. GENERAL ANESTHETICS
NITROUS OXIDE
THEREFORE,
Nitrous oxide combined with a halogenated inhalational anesthetic (N2O/O2)
DECREASES THE MAC
N2O/O2 is given throughout most surgical procedures that necessitate the use of general anesthesia because it reduces the concentration of other agents needed to obtain the desired depth of anesthesia.
Nitrous oxide does not increase the MAC of halogenated anesthetics. Nitrous oxide is commonly given with halogenated anesthetics without fear of toxic reactions. Nitrous oxide has no influence on the metabolism of halogenated anesthetics, many of which are sparingly metabolized.

117. GENERAL ANESTHETICS
NITROUS OXIDE
The average percentage of nitrous oxide required for patient comfort is 35%.
DELIVERY:
100% O2 (2-3 minutes) → N2O added in 5-10% increments → until patient response indicates level of sedation reached→ after termination of N2O, 100% O2 (at least 5 minutes)
The percentage of nitrous oxide required for patient comfort is variable and may range from 10% to 50%.

118. WHY SHOULD THE CLIENT BE PLACED ON 100% OXYGEN AFTERWARDS?

119. TO AVOID DIFFUSION HYPOXIA

120. NITROUS OXIDE Advantages of the N2O/O2 technique
GENERAL ANESTHETICS
NITROUS OXIDE
Advantages of the N2O/O2 technique
rapid onset – less than 5 minutes
easy administration – inhalation (no needles)
close control – via flow meters
rapid recovery – no need for designated driver
acceptability for children – apprehensive children
relaxed dental team

121. PHARMACOLOGIC EFFECTS
GENERAL ANESTHETICS
NITROUS OXIDE
PHARMACOLOGIC EFFECTS
The best indicator of the degree of sedation is the patient’s response to questions
The patient may exhibit slurred speech or a slow response
The patient is relaxed and cooperative and reports a feeling of euphoria
The patient is easily able to maintain an open-mouth position in the desired plane
The patient’s eyes may be closed but can be opened easily
The respiration, pulse, rate, and blood pressure are within normal limits

122. WHAT COLOR IS THE NITROUS TANK?

123. BLUE
**REMEMBER THIS!

124. DON’T GET THESE MIXED UP!!
GENERAL ANESTHETICS
NITROUS OXIDE
ADVERSE REACTIONS
Complications have been the result of misuse or faulty installation of equipment
NO2 tank → blue
O2 tank → green
DON’T GET THESE MIXED UP!!
Know the colour of the tanks/cylinders.
Cylinders are “pin coded” to prevent mixing of cylinders and lines
NO2 concentration should be automatically limited and have a fail-safe system that shuts off automatically if the O2 runs out

125. WHEN SHOULD NITROUS NOT BE USED?

126. IF THEY HAVE TROUBLE BREATHING…
Use of nitrous oxide is contraindicated in patients with any type of
upper respiratory or pulmonary obstruction

127. CONTRAINDICATIONS AND DENTAL ISSUES PREGNANCY CONSIDERATIONS
GENERAL ANESTHETICS
NITROUS OXIDE
CONTRAINDICATIONS AND DENTAL ISSUES
PREGNANCY CONSIDERATIONS
Safety of use in pregnant patients or administration by pregnant operators is in question
The incidence of spontaneous abortion or miscarriages is higher in female operating personnel chronically exposed to anesthetic agents or in wives of male operators

128. OTHER GENERAL ANESTHETICS CHARACTERISTICS OF PROPOFOL
INTRAVENOUS
propofol
(Diprivan)
CHARACTERISTICS OF PROPOFOL
a. Rapid onset of action
b. Potent vasodilator
c. Undergoes phase II metabolism in the liver
d. Intravenous anesthetic
e. An agent that is unrelated to any other general anesthetic

129. WHAT ARE THE PROPERTIES OF GOOD GENERAL ANESTHETIC?

130. NO TOXIC EFFECTS…