Local Anesthesia

Question 1

What is the drug of choice for local anesthesia in veterinary medicine?

Answer 1

Bupivacaine

0.5% solution or 5mg/ml

Question 2

What kind of blocks take care of each arch?

Answer 2

Caudal blocks

Question 3

What are the possible reactions to local anesthetics?

Answer 3

Toxicity to skeletal muscle
Anaphylactic reactions
Permanent nerve damage

Question 4

What is a simple rule to avoid toxicity in dogs and cats?

Answer 4

Never exceed 2.0 mg/kg

Question 5

What is the least effective method of local anesthesia?

Answer 5

Infiltration blocks

Question 6

When are infiltration blocks used?

Answer 6

After the procedure in an attempt to reduce postoperative discomfort

Question 7

What do infiltration blocks do?

Answer 7

Only effective in the area of infiltration

Question 8

What is the advantage of regional anesthesia?

Answer 8

The ability to block entire quadrants

Question 9

What are the disadvantages of regional nerve blocks?

Answer 9

loss of sensation and function of the area blocked

postoperative self-inflicted injury

Question 10

Where is the maxilla blocked?

Answer 10

The rostral or caudal maxilla

Question 11

What does the rostral maxillary infiltrate?

Answer 11

The infraorbital nerve

Question 12

What does the rostral maxillary block anesthetize

Answer 12

INcisors
Canines
First three premolar
Maxillary bone 
Surrounding soft tissue

Question 13

What does the caudal maxillary block anesthetize?

Answer 13

Both maxillary nerve
Sphenopalatine nerve/ganglia
All maxillary teeth on the side of the infiltration
Adjacent bone & soft tissue

Question 14

What does the rostral mandibular block anesthetize?

Answer 14

The inferior alveolar nerve

Question 15

Which block has limited effectiveness and the caudal block is recommended instead?

Answer 15

The rostral mandibular block

Question 16

What does the caudal mandibular block anesthetize?

Answer 16

Incisors
Canines
First two premolars
Adjacent bone and soft tissue

Question 17

What does the caudal mandibular block infiltrate?

Answer 17

The inferior alveolar nerve on the lingual aspect of the mandible

Question 18

When performing the rostral maxillary and caudal maxillary blocks, retract the lip dorsally and palpate where?

Answer 18

Just dorsal to the distal root of the maxillary 3rd premolar

Question 19

What is beneath the vestibular mucosa and is palpated as a large cylindric band that exits the infraorbital canal and is retracted dorsally with a digit of the hand not holding the syringe?

Answer 19

The infraorbital neurovascular bundle

Question 20

How is proper insertion confirmed?

Answer 20

By gentle movement of the syringe as the needle hits the infraorbital canal wall

Question 21

Why is it important that the syringe and needle are parallel to the dental arch line of the maxilla?

Answer 21

The infraorbital canal is very short (especially in cats and brachiocephalic dogs)

Question 22

Where does the rostral mandibular block infiltrate?

Answer 22

The rostral extent of the inferior alveolar nerve just before it exits the middle mental foramen

Question 23

What is the landmark for the rostral mandibular block?

Answer 23

Mandibular labial frenulum

Question 24

What is retracted ventrally?

Answer 24

The frenulum

Question 25

For the rostral mandibular block, where is the needle inserted?

Answer 25

At the rostral aspect of the frenulum

Question 26

For the rostral mandibular block, after the needle is inserted where is it advanced?

Answer 26

Along the mandibular bone at a 30-degree angle to just enter the canal

Question 27

How is the caudal mandibular block performed?

Answer 27

By palpating extra orally the notch just dorsal to the angle of the mandible and ventral to the condylar process

Question 28

Why is it important that the needle tip is located caudal to the foramen and rostral to the angular process of the mandible?

Answer 28

The inferior mandibular nerve is located outside of the mandibular canal

Question 29

When advancing the needle for the caudal mandibular block, the third molar in the dog and the first molar in the cat are used as landmarks, but the first molar is missing in cats, what is done instead?

Answer 29

The mandibular notch is palpated, the position of the first molar is approximated, and the needle is directed to the injection site

Question 30

What is an alternative method used for a landmark for the caudal mandibular block?

Answer 30

The lateral canthus of the eye

An imaginary line is drawn from the lateral canthus of the eye directly to the ventral mandible

Question 31

Why is it important to be careful not to anesthetize the tissues of the tongue?

Answer 31

The patient could wake up, not feel its tongue and chew its tongue

Question 32

If the tongue tissues are anesthetized, how is it treated?

Answer 32

The distraction of the patient
Sedation
General anesthesia until the regional anesthesia wears off or dysphoria stops

Question 33

What is the best treatment for anesthetizing the tongue?

Answer 33

Prevention by keeping the bevel of the needle pointed toward the mandible and staying right on the mandible as the needle is advanced

Question 34

Because of the opioid receptors in the peripheral nervous system, what opioid has been shown to effectively double the analgesic duration when combined with bupivacaine?

Answer 34

Buprenorphine