Locoregional Nerve Blocks- Large Animal Flashcards Preview

Anesthesiology > Locoregional Nerve Blocks- Large Animal > Flashcards

Flashcards in Locoregional Nerve Blocks- Large Animal Deck (42):
1

What species are auriculopalpebral blocks performed in?

Equine and bovine

2

T/F: Auriculopalpebral blocks are sensory blocks ONLY.

False- only motor blocks, eyelids and cornea remain sensitive

3

Where is the injection placed for an auriculopalpebral block in a horse?

Most dorsal point of the zygomatic arch

4

Which muscle is paralyzed with auriculopalpebral blocks?

Obicularis oculi

5

What does the supraorbital block effect?

Sensory to middle 2/3 of upper eyelid and palpebral motor

6

Where is a supraorbital block injection placed?

Supraorbital foramen

7

What is a supraorbital block used for?

Placement of sub-palpebral lavage catheter

8

Is an equine retrobulbar block the same procedure as in small animal?

Yes

9

Where is an infraorbital block placed?

At the exit of the infraorbital canal

10

What area does an infraorbital block effect?

Exit of canal: Sensory to the upper lip and nose

Inside canal: teeth rostral to first molar, maxillary sinus, roof of nasal cavity

11

What does a mental nerve block do?

Desensitize the lower lip

12

Why are caudal epidurals used in horses?

Because you don't want to lose hindlimb motor function.

13

What are some indications for a caudal epidural?

1. Control of rectal tenesmus
2. Obstetric procedures
3. Tail amputation, rectovaginal fistura repairs
4. Hindlimb procedures and pain

14

Where are caudal epidurals placed?

First coccygeal space- first movable joint when tail is manipulated

15

Should LAs be used in equine epidurals?

They can, but must limit spread cranially

Lidocaine 2% 6-8mL usually sufficient in an adult horse

16

Can Alpha-2 agonists be used in equine epidurals?

Yes, more commonly used (xylazine and detomidine)

May cause systemic effects

17

Can morphine be used in equine epidurals?

Yes- provides analgesia without risk of motor junction impairment

Often mixed with detomidine

18

Should epidural catheters be used with local anesthetics in horses?

No- motor blockade

19

How much lidocaine should be injected into the testicle for a castration?

Enough so that it feels firm- usually around 20mL

20

Does a testicular injection provide cutaneous analgesia?

No

21

When is inta-articular morphine typically used?

Analgesia and anti-inflammatory post-arthroscopy

22

What is a peterson block?

Similar block as retrobulbar but is more difficult to perform.

23

What nerves does a peterson block effect?

Oculomotor, trochlear, abducens, trigeminal

24

T/F: Both retrobulbar and peterson blocks prevent blinking for several hours.

True- eyes should be lubricated and animals should be kept out of the sun/dust/wind until motor function returns

25

Which nerves should be blocked for dehorning in cattle and goats?

Cattle- cornual branch of zygomaticotemporal

Goats- cornual branch of zygomaticotemporal and cornual branch of intratrochlear

26

What are the techniques for a ruminant flank laparotomy?

Infiltration- Line block or inverted L block

Regional- proximal or distal paravertebral

27

What is a line block?

Injecting LA subcutaneously along the incision line

28

What is an inverted L block?

Injections of idocaine into the area dorsocaudal to the last rib and ventrolateral to lumber transverse processes

29

Is the LA injected along the incision line in an inverted L block?

No

30

what are some other names for a proximal paravertebral thoracolumbar block?

Farquharson, hall, or cambridge technique

31

Which nerves are effected in a proximal paravertebral thoracolumbar block?

Dorsal and ventral branches of T13-L2

32

Where is the injection placed in a proximal paravertebral thoracolumbar block?

3-5cm from dorsal midline

33

What are signs of a successful proximal paravertebral thoracolumbar blockade?

1. Analgesia of skin
2. Increase skint temp
3. Spinal scoliosis towards desensitized side

34

What are some disadvantages of a proximal paravertebral thoracolumbar block?

1. Technically difficult
2. Scoliosis may impair incision closure
3. Risk of penetrating great vessels
4. Loss of motor control if LA migrates to femoral

35

Which nerves are effected by a distal paravertebral thoracolumbar block?

Dorsal and ventral branches of T13-L2 also transverse of L1, L2, and L4

36

What are the advantages of a distal paravertebral thoracolumbar block versus proximal?

Lack of scoliosis and less risk of damaging blood vessels

37

What are the disadvantages of a distal paravertebral thoracolumbar block?

Larger amount of local anesthetic and may be less effective

38

What kinds of animals are lumbosacral epidurals used in?

Immature cattle, small ruminants, camelids, and pigs

39

What drugs are used in lumbosacral epidurals for large animals?

Alpha-2 agonists

40

T/F: Local anesthesia can be done on the teat to treat lacerations or other injuries.

True- ring blocks, inverted IV blocks, teat cistern infusion, IVRA

41

Which nerves are blocked in order to anesthetize the udder?

Paravertebral block of L1-L3 or high caudal/LS epidural

42

What kind of blocks are done to anesthetize the feet?

Ring block or IVRA