Locoregional Nerve Blocks- Small Animal Flashcards Preview

Anesthesiology > Locoregional Nerve Blocks- Small Animal > Flashcards

Flashcards in Locoregional Nerve Blocks- Small Animal Deck (66):
1

What are the four methods of local anesthesia?

1. Topical
2. SubQ
3. Line blocks
4. Wound soaker catheter

2

What are two types of topical anesthesia administration?

1. EMLA cream- lidocaine + prilocaine)
2. Lidoderm- 5% lidocaine patches

3

Do lidoderm patches provide a complete block?

No- only analgesic effects

4

What drugs are used for opthalmic analgesia?

Tetracaine or proparacaine

5

What drug is used for laryngeal anesthesia?

2% lidocaine- usually for intubation

6

What is SQ local anesthesia used for?

Wounds, masses, or biopsy

7

T/F: Ventral midline blocks have conflicting evidence for actually decreasing pain.

True

8

What is a wound soaker catheter?

A long fenestrated closed tip catheter that is placed during surgery deeply close to visualized nerves

9

What are wound soaker catheters used for?

1. Total ear canal ablation
2. Amputation
3. Oncology surgery
4. Large wound closure

10

What are complications associated with wound soaker catheters?

1. Catheter dislodgement or disconnection
2. Local anesthetic toxicity
3. Delayed wound healing

11

What are some advantages to wound soaker catheters?

1. Technically simple
2. Consistent and prolonged analgesia
3. Decreased need for systemic analgesics

12

What are the indications for a bier block?

Distal extremity procedures

13

What are some advantages of a bier block?

1. Simple and reliable
2. Minimal blood loss and clear field

14

What is the procedure for a bier block?

1. Place distal IVC
2. Exsanguinate limb (elevate or tight wrapping)
3. Place tourniquet proximally
4. Remove bandage
5. Inject lidocaine and allow to sit
6. Remove catheters and tourniquet

15

What are some IVRA complications?

1. Pain
2. Ischemia/nerve injury
3. Limb swelling
4. Hematoma
5. Local anesthetic toxicity

16

What are indications for a retrobulbar block?

- Enucleation
- Eviscceration/prosthesis
- Intraocular surgery

17

What nerves are effected in a retrobulbar block?

CN III, IV, V, VI, ciliary ganglion

18

What are the advantages to a retrobulbar block?

1. Post-op analgesia
2. Globe immobility during sx
3. Decreased anesthetic and NMBD requirements

19

What are potential complications of a retrobulbar block?

- Retrobulbarr hemorrhage
- Damage to optic nerve or extraocular muscles
- Globe penetration
- Intravascular injection
- Intrathecal injection

20

What is the preferred technique for a retrobulbar block?

Interior-temporal palpebral

21

If there is resistance to injection during a retrobulbar block, what does this indicate?

Needle is within the optic nerve sheath and proceeding may be fatal

22

What nerve does a maxillary nerve block affect?

Sensory branch of CN V

23

What areas are anesthetised in a maxillary nerve block?

Maxilla and teeth/soft tissues, lateral nasal mucosa

24

`What are the three techniques for a maxillary nerve block?

1. Subzygomatic
2. Maxillary tuberosity (intraoral)
3. Infraorbital

25

What does an infraorbital block provide anesthesia for?

3rd premolar and all teeth rostral, rostral maxilla and soft tissues

26

Where is an infraorbital nerve block placed?

Into the infraorbital foramen

27

Is an intraoral or extraoral technique perfered in cats?

Extraoral

28

What does an inferior alveolar block provide anesthesia for?

Mandibular teeth, rostral lower lip, intermandibular space

29

Where is the injection given for an inferior alveolar block?

Medial aspect of mandible adjacent to mandibular foramen

30

What other nerve may be affected in an inferior alveolar block?

Lingual nerve- loss of sensory innervation to the rostral 2/3 of tongue

31

What does a mental block provide anesthesia for?

Rostral lower lip only

32

Where is the injection places for a mental nerve block?

Over palpable middle mental foramen, intra or extraorally

33

What does an cervical paravertebral block provide anesthesia for?

Entire thoracic limb including the scapula and shoulder joint

34

Which nerves are effected in a cervical paravetebral block?

Ventral branches of C6, C7, C8, T1, spinal nerves, proximal to brachial plexus

35

Are cervical paravertebral blocks commonly used?

No, very technically difficult

36

What does a brachial plexus block provide anesthesia for?

Thoracic limb below them elbow

37

Which nerves are effected in a brachial plexus block?

Suprascapular, musculocutaneous, radial, medial, and ulnar

38

Is a nerve locator preferred when performing a brachial plexus block?

Yes, but ultrasound can be used

39

What is a RUMM block used for?

Anesthesia of the distal thoracic limb including the carpus

40

Which nerves are effected by a RUMM block?

Radial, ulnar, median, and musculocutaneous

(That's what RUMM stands for.....)

41

T/F: RUMM blocks are achieved with one injection.

False- two injections are required, one medially and one laterally

42

T/F: Declaws are illegal in some places.

True

43

What drug is used for declaw blocks?

Bupivacaine

44

T/F: Femoral and sciatic blocks are typically performed together.

True

45

Pelvic limb blocks anesthetize what?

Pelvic limb distal to the mid-femur

46

T/F: Pelvic limb blocks are as effective as an epidural for stifle surgery.

True

47

What are some indications for using an intercostal block

Thoracotomy, rib fractures, thoracic procedures, etc

48

T/F: Intercostal blocks should be performed along the cranial aspect of the rib.

False- the VANs run along the caudal aspect

49

T/F: Intercostal blocks should be performed at the incision site and the two surrounding rib spaces.

True

50

What should the orientation of the effected side be when performing intrapleural regional blocks?

Down, because gravity. At least 20 min after injection

51

Where are epidurals most commonly places in small animals?

L-S space

52

Should epidurals be performed on awake animals?

No, heavy sedation or anesthesia is required

53

What are two options for administering an epidural?

1. Single injection
2. Indwelling catheter

54

T/F: Epidurals can be performed with the animal in sternal or lateral recumbancy.

True- sternal is preferred

55

What is the loss of resistance technique for epidurals?

Feeling for a pop when advancing the needle- indicates you are through the ligaments

56

Is it recommended to inject air using the LOR technique to confirm placement?

No- use saline or the epidural drug

57

What is the hanging drop technique for eipdurals?

Watching for the fluid in the hub of the needle to be pulled into the space

58

What principle does the hanging drop technique work on?

The epidural space being subatmospheric pressure

59

Is the hanging drop more reliable in large or small patients?

Large

60

Are nerve locators commonly used in epidurals?

No

61

T/F: Higher volumes of injection are more likely to spread cranially.

True- risk for sympathetic blockade especially with LA drugs

62

What volume will be sufficient to reach L1?

0.2 mL/kg

63

T/F: Most commonly a local anesthetic and an opioid are used in combination in an epidural.

True- usually bupivicaine and morphine

64

T/F: Morphine produces more cranial spread and a longer duration with an epidural than using a LA alone

True- may produce anesthesia in the thoracic wall/limbs

65

What are some complications of an epidural injection?

1. Intrathecal injection
2. Neural damage/toxicity
3. Infection
4. Hypotension

66

What are some complications of epidural opioids?

Urinary retention and puritis (uncommon)