Local Anesthesia

Question 1

Why is local and regional anesthesia important?

Answer 1

Allows examination and procedure without GA
Analgesia without systemic effect
Combine with sedation
Balanced

Question 2

What are some choices for local anesthetics and what is there duration?

Answer 2

Lidocaine: 1-2hr
Mepivacaine: 1-2hr
Bupivacaine: 4-6hr

Question 3

What 2 main blocks are important for examination of the eye?

Answer 3

Auriculopalpebral (motor)
Supraorbital (sensory)

Question 4

What is a topical anesthetic you can put on the eye?

Answer 4

Proparacaine - 15 sec onset and 15-30min duration

Question 5

Describe the auriculopalpebral block?

Answer 5

Most important motor block
25G 1inch needle
1-2ml lidocaine
Paralysis of eyelid
Infiltrate caudal aspect zygomatic arch (dorsal)

Question 6

Describe the supraorbital block?

Answer 6

Sensory to upper eyelid
25 g 1inch
1-2ml lidocaine
Over the supraorbital foramen

Question 7

What are some other local blocks of the eye?

Answer 7

Lacrimal - temporal canthus and upper lid (lateral)

Infratrochlear - nasal anthus

Zygomaticofacial - temporal lower lid

Question 8

What block would you need to perform if the horse tore its upper lip or nose?

Answer 8

Infraorbital I
-inject over infraorbital foramen (use nasal notch and facial crest)
-4-5ml local

Question 9

What block would you need to perform if 1st molar needed to be removed? (Maxillary sinus, roof nasal cavity, skin medial anthus)

Answer 9

Infraorbital II - thread needle into infraorbital foramen (horse hate)

Question 10

What block should you perform if you need to enter the nasal cavity or sinus? (all upper teeth)

Answer 10

Maxillary block

3.5in needle ventral to zygomatic process, dorsal to vessels, cd 1/3 eye
15-20ml

Question 11

What block would you need to perform if a bottom tooth needed to be removed?

Answer 11

Mandibular - lateral canthus mandibular cheek teeth

20G 6 inch, 10-15cm

15-20ml

Question 12

What block would you perform if the lower lip needed repairing?

Answer 12

Mental I
-5ml over mental foramen
-Push depressor labi inferioris dorsal

Mental II - lower incisior and 3rd premolar, into foramen 5-10ml

Question 13

What are indication for a epidural?

Answer 13

Procedure involving the rectum, vagina, perineum, urethra and bladder
Obstetric manipulation
Analgesia to stifle and hock
Intraoperative

Question 14

When should you not do an epidural?

Answer 14

Infection at puncture site, sepsis, hypovolemia, anticoagulation RX, anatomic abnormalities

Question 15

Is the epidural space the same as the subarachnoid?

Answer 15

NO

Question 16

What is the difference between the Lumbosacral and Caudal approach?

Answer 16

Lumbosacral: subarachnoid easier, fastest and best flank anesthesia, need equipment and sterile tech

Caudal - simple, no equipment, preserve locomotor function hindlimb

Question 17

How do you prepare a horse for a n epidural?

Answer 17

Proper restraint (stock and sedation)
Stand square
Clip and prep skin
sterile glove and supplise
Lidocaine block

Question 18

What are the landmarks for lumbosacral?

Answer 18

1-2cm caudal line from cranial edge tuber sacrale and dorsal midline
-17.5-17g spinal needle

Question 19

What are the landmarks for a caudal epidural?

Answer 19

palpate co1 and co2 as first midline depression caudal to sacrum (moveable) when raised
18G 1.5 inch
center space perpendicular, pop feel

Question 20

Which epidural is preferred? Why?

Answer 20

Caudal
-Less risk
-Wont blockade and ataxia

Question 21

What technique should you use for epidural?

Answer 21

Hanging drop, loss resistance, inject easy and bubble does not compress

Question 22

What can you use in an epidural?

Answer 22

Alpha 2 opioid (morphine and butorphanol), ketamine

Question 23

What does an alpha 2 work on when in epidural form?

Answer 23

Hind end and systemic

Question 24

Do you need more or less opioid in an epidural?

Answer 24

Less

Question 25

What is the difference between PF and regular morphine?

Answer 25

PF = preservative free
-Larger volume
-More expensive
-Cant repeat does (cant if preservative)

Question 26

What are complication of an epidural?

Answer 26

Failure to achieve analgesia
Hypoventilation
Bradycardia
Puritis
Upward fixation patella
Sepsis
Recumbency