CDCA Review: Local Anesthesia Test With
Complete Solutions
What local anesthetic is metabolized by pseudocholinesterase? - correct answer-
Esters
Where are ester local anesthetics hydrolyzed? - correct answer- In the blood plasma
by the enzyme pseudocholinesterase
Which antiseptic should not be used? - correct answer- Liquid Alcohol
Before using a cartridge you should:
1) wipe it with disinfectant
2) soak it in alcohol
3) autoclave it and or sterilize it? - correct answer- None of the above
What part of the syringe indicates that it is an aspirating syringe? - correct answer-
Harpoon
What is a possible cause of pain on removal of the needle? - correct answer- Needle
barb from impaling bone
If there is no organic basis for pain - correct answer- Psychogenic pain
How does a self aspirating syringe work - correct answer- When you let off pressure
from injecting it self-aspirates (negative pressure built into the syringe)
When do you aspirate? - correct answer- Immediately before you inject local
anesthetic
,What is the action of vasodepressors in local anesthetic? - correct answer- increases
depth and duration of anesthetic, decreases absorption of local anesthetic and
vasopressor
Maximum Doses of Epinephrine - correct answer- Normal healthy patient - .2 mg
Cardiac patient - .04 mg
How much epinephrine is in a cartridge of 1:50,000 epinephrine? - correct
answer- .036 mg
How much epinephrine is in a cartridge of 1:100,000 epinephrine? - correct
answer- .018 mg
How much epinephrine is in a cartridge of 1:200,000 epinephrine? - correct
answer- .009 mg
What causes a hematoma? - correct answer- Effusion of blood into extravascular
spaces and can result from nicking a blood vessel, artery or vein. Common in pterygoid
plexus of veins with a PSA injection.
Treatment of Hematoma - correct answer- Apply pressure for at least 2 minutes, Ice
the area immediately, and then use warm moist towels 4-6 hours after to area, rinse
with salt water
In which injection is a hematoma most likely to occur? - correct answer- PSA
What is the volume of local anesthetic in a cartridge? - correct answer- 1.8 mL or 1.7
mL
How do you determine gauge and lumen size of a needle? - correct answer- Smaller
the number, larger the lumen
30 = small
27 = intermediate
25 = large
Which needle gauge has the smallest lumen? - correct answer- 30 gauge
What sensation is lost first? - correct answer- Pain
What function does sodium chloride provide in local anesthetic solution? - correct
answer- Makes the solution isotonic with tissue
What antioxidant prevents biodegradation of vasoconstrictors? - correct answer-
Sodium (Meta) Bisulfite
, What is the role of sodium bisulfite in local anesthetic? - correct answer- Antioxidant
prevents oxidation of the vasopressor by oxygen which might be trapped in the cartridge
by the manufacturer or diffuse through the cartridge's latex diaphragm
Primary cause of needle separation (breakage)? - correct answer- Weakening of the
dental needle by bending it before insertion into the patient's mouth
2nd most common reason is patient movement during injection
When does a patient receive an electrical shock sensation during and injection? -
correct answer- When needle contacts the nerve sheath
Why does infiltration work better in the maxilla? - correct answer- Less bone density
(thinner cortical plate of bone)
Which local anesthetic is not an amide? - correct answer- Procaine (Novacain)
How long can you safely leave a Dentipatch (EMLA) on tissue? - correct answer- 15
minutes
Most commonly used plain local anesthetic? - correct answer- 3% Mepivacaine Plain
What gauge needle can be used for infiltration injections? - correct answer- 27 or 30
gauge
Which local anesthetic is an ester? - correct answer- Procaine (Novacain)
Why would you use caution with an amide if a patient has liver (cirrhosis) disease? -
correct answer- Amides metabolized in the liver
After infraorbital injection why does the patient's cheek turn white? - correct answer-
Blanching or vasoconstriction of blood vessels in the area
Why does anesthesia fail to work near an infected tooth? - correct answer- Infection
causes a lower pH in the tissue
(less free base local anesthetic molecules available to penetrate the nerve membrane)
If a patient has an allergic reaction to an amide, what could you use to inject the
patient? - correct answer- Ester local anesthetic
If a patient is allergic to both amides and esters, what could you use to inject the
patient? - correct answer- Diphenhydramine (Benadryl)
What nerve innervates the soft palate? - correct answer- Lesser palatine
If the pharynx (throat) is numb, what nerve was anesthetized? - correct answer-
Glossopharyngeal (Cranial Nerve IX)
Complete Solutions
What local anesthetic is metabolized by pseudocholinesterase? - correct answer-
Esters
Where are ester local anesthetics hydrolyzed? - correct answer- In the blood plasma
by the enzyme pseudocholinesterase
Which antiseptic should not be used? - correct answer- Liquid Alcohol
Before using a cartridge you should:
1) wipe it with disinfectant
2) soak it in alcohol
3) autoclave it and or sterilize it? - correct answer- None of the above
What part of the syringe indicates that it is an aspirating syringe? - correct answer-
Harpoon
What is a possible cause of pain on removal of the needle? - correct answer- Needle
barb from impaling bone
If there is no organic basis for pain - correct answer- Psychogenic pain
How does a self aspirating syringe work - correct answer- When you let off pressure
from injecting it self-aspirates (negative pressure built into the syringe)
When do you aspirate? - correct answer- Immediately before you inject local
anesthetic
,What is the action of vasodepressors in local anesthetic? - correct answer- increases
depth and duration of anesthetic, decreases absorption of local anesthetic and
vasopressor
Maximum Doses of Epinephrine - correct answer- Normal healthy patient - .2 mg
Cardiac patient - .04 mg
How much epinephrine is in a cartridge of 1:50,000 epinephrine? - correct
answer- .036 mg
How much epinephrine is in a cartridge of 1:100,000 epinephrine? - correct
answer- .018 mg
How much epinephrine is in a cartridge of 1:200,000 epinephrine? - correct
answer- .009 mg
What causes a hematoma? - correct answer- Effusion of blood into extravascular
spaces and can result from nicking a blood vessel, artery or vein. Common in pterygoid
plexus of veins with a PSA injection.
Treatment of Hematoma - correct answer- Apply pressure for at least 2 minutes, Ice
the area immediately, and then use warm moist towels 4-6 hours after to area, rinse
with salt water
In which injection is a hematoma most likely to occur? - correct answer- PSA
What is the volume of local anesthetic in a cartridge? - correct answer- 1.8 mL or 1.7
mL
How do you determine gauge and lumen size of a needle? - correct answer- Smaller
the number, larger the lumen
30 = small
27 = intermediate
25 = large
Which needle gauge has the smallest lumen? - correct answer- 30 gauge
What sensation is lost first? - correct answer- Pain
What function does sodium chloride provide in local anesthetic solution? - correct
answer- Makes the solution isotonic with tissue
What antioxidant prevents biodegradation of vasoconstrictors? - correct answer-
Sodium (Meta) Bisulfite
, What is the role of sodium bisulfite in local anesthetic? - correct answer- Antioxidant
prevents oxidation of the vasopressor by oxygen which might be trapped in the cartridge
by the manufacturer or diffuse through the cartridge's latex diaphragm
Primary cause of needle separation (breakage)? - correct answer- Weakening of the
dental needle by bending it before insertion into the patient's mouth
2nd most common reason is patient movement during injection
When does a patient receive an electrical shock sensation during and injection? -
correct answer- When needle contacts the nerve sheath
Why does infiltration work better in the maxilla? - correct answer- Less bone density
(thinner cortical plate of bone)
Which local anesthetic is not an amide? - correct answer- Procaine (Novacain)
How long can you safely leave a Dentipatch (EMLA) on tissue? - correct answer- 15
minutes
Most commonly used plain local anesthetic? - correct answer- 3% Mepivacaine Plain
What gauge needle can be used for infiltration injections? - correct answer- 27 or 30
gauge
Which local anesthetic is an ester? - correct answer- Procaine (Novacain)
Why would you use caution with an amide if a patient has liver (cirrhosis) disease? -
correct answer- Amides metabolized in the liver
After infraorbital injection why does the patient's cheek turn white? - correct answer-
Blanching or vasoconstriction of blood vessels in the area
Why does anesthesia fail to work near an infected tooth? - correct answer- Infection
causes a lower pH in the tissue
(less free base local anesthetic molecules available to penetrate the nerve membrane)
If a patient has an allergic reaction to an amide, what could you use to inject the
patient? - correct answer- Ester local anesthetic
If a patient is allergic to both amides and esters, what could you use to inject the
patient? - correct answer- Diphenhydramine (Benadryl)
What nerve innervates the soft palate? - correct answer- Lesser palatine
If the pharynx (throat) is numb, what nerve was anesthetized? - correct answer-
Glossopharyngeal (Cranial Nerve IX)
