Chapter 10 - Patient Assessment for Local Anesthesia

Question 1

1. The delivery of local anesthesia requires both medical and technical skills. Which ONE of the following is NOT one of the six elements elements of the ASA Medical Components of Care associated with regional anesthesia?
   a. Pre-anesthetic evaluation of the patient
   b. Comprehensive tooth charting
   c. Remain present during the course of the anesthesia
   d. Providing indicated post-anesthesia care

Answer 1

b. Comprehensive tooth charting

Question 2

The ASA Physical Status Classification System categorizes patients based on their overall health. Classification P3 describes which ONE of the following?

a. Normal healthy patient
b. Severe Systemic Disease
c. Moribund Patient
d. Severe Systemic Disease (constant threat to life)

Answer 2

b. Severe Systemic Disease

Question 3

3. Which of the following is NOT considered a main tool for patient assessment when planning for local anesthesia?

a. The medical/dental questionnaire
b. The clinical examination
c. Drug MRDs
d. Medical consultation

Answer 3

c. Although important when monitoring total doses of drug delivered, this is not considered a main TOOL for patient assessment.

Question 4

4. Which ONE of the following drugs is an absolute contraindication for patients with poorly controlled or uncontrolled hyperthyroidism?

a. Lidocaine
b. Bupivacaine
c. Epinephrine
D. Felypressin

Answer 4

c. Epinephrine

Note: Felypressin is also a vasoconstrictor, HOWEVER, Felypressin has no adrenergic effects and is therefore safe to use for patients with hyperthyroidism.
[Felypressin not available in dental LA/dental cartridges in the U.S.]

Question 5

5. Your patient has identified or you suspect that your has used methamphetamines ~ 20 hours ago. Which of the following would be the most appropriate action when considering the use of LA?

a. Continue w/ procedures, as it has been > 12hrs. since the use.
b. Restrict the dose of vasoconstrictors to 20% of standard dose.
c. Consider postponing care for a full 24 hours.
d. Use only bupivacaine as the LA agent

Answer 5

c. Consider postponing care for a full 24 hours.

• admin. of vasoconstrictors may result in hypertensive crisis, stroke, or MI.
• recommended NOT TO ADMINISTER vasoconstrictors for a full 24 hours after using methamphetamines

Question 6

6. For which ONE of the following medical conditions is it unnecessary to obtain a medical consultation from the pt’s physician before dental tx?

a. Significant liver disease
b. Myocardial infarction within 3 weeks
c. Kidney dialysis patients
d. Organ transplant patients

Answer 6

b. - MI within 3 weeks is an absolute contraindication to care.

Question 7

Q10-1: What is the American Society of Anesthesiologists (ASA) most important goal in the delivery of anesthesia?

Answer 7

A10-1: patient safety

Question 8

Q10-2: List the ASA’s [6] Medical Components of Care.

Answer 8

A10-2:

1. Preanesthetic evaluation of pt
2. Prescription of anesthetic plan
3. Personal participation in technical aspects of the regional anesthetic
4. Following the course of the anesthetic
5. Remaining physically available for the immediate diagnosis and treatment of emergencies
6. Providing indicated postanesthesia care

Question 9

Q10-3: Describe the six classes of the ASA Physical Status Classification System.

Answer 9

A10-3:
ASA I normal healthy patient
ASA II mild systemic disease
ASA III severe systemic disease
ASA IV severe systemic disease that is a constant threat to life
ASA V moribund patient who is not expected to survive without the operation
ASA VI declared brain-dead patient whose organs are being removed for donor purposes

Question 10

Q10-4: ASA classification for Asthma

Answer 10

A10-4: ASA II

Question 11

Q10-5: ASA classification for Epilepsy

Answer 11

A10-5: ASA II

Question 12

Q10-6: ASA classification for Congestive heart failure

Answer 12

A10-6: ASA III

Question 13

Q10-7: ASA classification for Hypothyroidism

Answer 13

A10-7: ASA II

Question 14

Q10-8: ASA classification for Chronic obstructive pulmonary disease requiring oxygen

Answer 14

A10-8: ASA IV

Question 15

Q10-9: Define the term concomitant.

Answer 15

A10-9: Drugs in a patient’s system when local anesthetics are administered

Question 16

Q10-10: Give four reasons it is important for a clinician to know what concomitant drugs a patient is taking.

Answer 16

A10-10:
1. They may influence the choice of LAD & dose
2. They may affect efficacy, metabolism, & elimination of a local anesthetic drug.
3. They may potentiate the action or delay the metabolism of LAD
4. Their actions may be affected by local anesthetic drugs.

Question 17

Q10-11: Give examples of the need for medical consultation prior to the administration of local anesthesia.

Answer 17

A10-11:
- symptoms of undiagnosed disease
- no regular medical exams
- gaps in the information provided
- pregnant
- other concerns suggest follow-up is necessary
- Medical conditions: CV conditions, recent surgeries, uncontrolled hypertension, psychological conditions that may influence oral procedures, compromised liver and/or kidney function, immune system compromise, and any concerns regarding local anesthesia and/or treatment.

Question 18

Q10-12: Why is it important to take vital signs before local anesthetics are administered?

Answer 18

A10-12:
- serve as baseline values; used for comparisons should adverse events develop after LA admin.
- abnormal vital signs may contraindicate LA admin

Question 19

Q10-13: Define functional capacity.

Answer 19

A10-13: Functional capacity is an assessment tool to identify when a medical risk is the greatest, and is expressed in metabolic equivalent of task (MET).

Question 20

Q10-14: Provide examples of physical activities an individual must be able to perform in a MET 4 capacity.

Answer 20

A10-14: At MET 4 capacity, individual can do light housework, move furniture, walk up a flight of stairs without chest pain, walk up a hill, walk on level ground at 4 mph, run a short distance, participate in activities such as dancing, golf, bowling, or play doubles tennis.

Question 21

Q10-15: Typically, most local anesthetic injections through tissue are not considered to be invasive and do not require antibiotic premedication. True? False?

Answer 21

A10-15: True.

Question 22

Q10-16: Patients with hemophilia and clotting disorders require antibiotic premedication and modification of injection types, drug selection, and doses of local anesthetics. True? False?

Answer 22

A10-16: False
however, these patients may require modification of injection types, drug selection, and doses

Question 23

Q10-17: In children, anxiety related to the administration of local anesthesia may provoke syncope or hyperventilation. In adults, anxiety more commonly provokes asthmatic episodes. True? False?

Answer 23

A10-17: False.
- children, anxiety due to LA admin may provoke asthmatic episodes
-adults, anxiety more commonly provokes syncope or hyperventilation

Question 24

Q10-18: The systemic effects of local anesthesia on the respiratory system are typically minimal. Epinephrine acts on β receptors of the smooth muscles of the bronchioles to dilate air passages. True? False?

Answer 24

A10-18: True

Question 25

Q10-19: A patient has taken a large dose of narcotics prior to local anesthetic administration. Local anesthetic drugs can have a profound effect on the central nervous system (CNS) because local anesthetic drugs are CNS stimulants. True? False?

Answer 25

A10-19: False. LADs can have a profound effect on CNS b/c they are CNS depressants
- additive to any existing CNS depression
- if CNS depression is suspected, careful evaluation is indicated; if narcotics were taken, LA can have an earlier and more profound effect on the CNS.

Question 26

Q10-20: Patients with sickle cell anemia should not receive local anesthesia with vasoconstrictors during a crisis without antibiotic prophylaxis. True? False?

Answer 26

A10-20: False.
- should not receive any LA (w/ or w/o vasoconstrictors) or any dental tx during a crisis

Question 27

Q10-21: Patients with extensive liver damage may not be able to metabolize ester local anesthetic drugs efficiently. True? False?

Answer 27

A10-21: False.
- extensive liver damage affects amide LA metabolism
- if ASA III = LA is relative CI:
* Ester & amide LAs can be used with caution
* Articaine, particularly in significant liver disease, may be advantageous b/c it largely avoids liver metabolic pathways when used for oral injections.

Question 28

Q10-22: Pregnancy poses a temporary and relative contraindication to local anesthetics, and the second trimester of pregnancy is considered the safest period for both the fetus and the mother. True? False?

Answer 28

A10-22: True

Question 29

Q10-23: Some patients experience allergic reactions to synthetic epinephrine. True? False?

Answer 29

A10-23: False
- true allergies impossible b/c synthetic (exogenous) epinephrine is identical to endogenous epinephrine
- if allergies have occurred, they are likely related to the hydrochloride or bitartrate component of the formulation. This occurrence is extremely rare.

Question 30

Q10-24: Individuals taking nonselective beta-blocking agents for hypertension or other conditions such as migraines should never be given epinephrine. True? False?

Answer 30

A-10-24: False.
- give epinephrine with caution
- epinephrine may increase blood pressure through inhibition of the vasodilatory action of epinephrine via the agents’ blocking of β-2 receptor activity
[inital alpha vasoncstiction of epinephrine works, but the later dilation via beta2 receptors is blocked by the beta blockers]

Question 31

Q10-25: Explain why it is important to minimize the amount of amide local anesthetic drugs for patients with compromised liver function.

Answer 31

A10-25: The amide local anesthetics are primarily metabolized in the liver where they are broken down into inactive metabolites for excretion. In the liver, they compete for metabolic pathways with other drugs. Compromised liver function can influence the blood levels of all drugs including their half-lives and excretion patterns.

Question 32

Q10-26: Why is it important to assess kidney function prior to the administration of local anesthetic drugs?

Answer 32

A10-26: The kidneys are the major excretory organs for local anesthetics. Inadequate excretion of local anesthetics and their metabolic byproducts may increase levels in the blood, possibly to toxic levels.

Question 33

Q10-27: Define relative contraindication.

Answer 33

A10-27: A relative contraindication for local anesthesia is one in which local anesthetics may be given, but with caution and/or modifications.

Question 34

Q10-28: Define atypical plasma cholinesterase.

Answer 34

A10-28: Atypical plasma cholinesterase impairs a patient’s ability to effectively metabolize ester-type local anesthetics in any form, injectable or topical. This condition is genetic (autosomal recessive) and has a frequency of approximately 1 in 3,000 patients.

Question 35

Q10-29: Define methemoglobinemia.

Answer 35

A10-29: Methemoglobinemia is a genetic or acquired condition which reduces the oxygen-carrying capacity of blood. Acquired methemoglobinemia has been reported following the administrations of benzocaine topical and injectable prilocaine anesthetics. Clinical anoxia may result from methemoglobin levels above 10%. Affected patients demonstrate signs of reduced oxygenation and cyanosis.

Question 36

Q10-30: Following a myocardial infarction, what is the current recommended guideline when considering elective dental treatment?

Answer 36

A10-30: A minimum of four weeks delay, with appropriate consultation and risk analysis, is recommended following a myocardial infarction before considering elective dental treatment.

Question 37

Q10-31: Following a CVA, TIA, or RIND, how long should elective dental treatment be delayed?

(RIND = reversible ischemic neurological deficit)

Answer 37

A10-31: One to six months, with appropriate consultation and risk analysis before considering elective dental treatment.

Question 38

Q10-32: What is the recommendation for use of vasoconstrictors with concomitant use of nonselective β-blockers?

Answer 38

A10-32: Unless vasoconstriction is necessary, avoid both epinephrine and levonordefrin. When vasoconstriction is necessary, limited doses may be used with caution.

Question 39

Q10-33: Why do local anesthetics with vasoconstrictors pose a serious risk with the concomitant use of cocaine?

Answer 39

A10-33: Cocaine is a potent vasoconstrictor and exhibits significant indirect-acting adrenergic stimulating effects. Vasoconstrictors in combination with cocaine significantly increase the risk of hypertensive crisis, stroke, and myocardial infarction. It is recommended that vasoconstrictors be avoided for 24 hours after cocaine use.

Question 40

Q10-34: Why do local anesthetics with vasoconstrictors pose a serious risk with the concomitant use of methamphetamine?

Answer 40

A10-34: Both methamphetamine and epinephrine are potent vasoconstrictors. In combination, they significantly increase the risk of hypertensive crisis, stroke, and myocardial infarction. Do not administer local anesthetics with vasoconstrictors for a minimum of 24 hours after methamphetamine use.

Question 41

Q10-35: Why are stress reduction protocols recommended when treating patients with anxiety and fear?