Locoregional Nerve Blocks- Small Animal Flashcards Preview

Anesthesiology > Locoregional Nerve Blocks- Small Animal > Flashcards

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

What are the four methods of local anesthesia?

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

What are two types of topical anesthesia administration?

A
  1. EMLA cream- lidocaine + prilocaine)

2. Lidoderm- 5% lidocaine patches

3
Q

Do lidoderm patches provide a complete block?

A

No- only analgesic effects

4
Q

What drugs are used for opthalmic analgesia?

A

Tetracaine or proparacaine

5
Q

What drug is used for laryngeal anesthesia?

A

2% lidocaine- usually for intubation

6
Q

What is SQ local anesthesia used for?

A

Wounds, masses, or biopsy

7
Q

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

A

True

8
Q

What is a wound soaker catheter?

A

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

9
Q

What are wound soaker catheters used for?

A
  1. Total ear canal ablation
  2. Amputation
  3. Oncology surgery
  4. Large wound closure
10
Q

What are complications associated with wound soaker catheters?

A
  1. Catheter dislodgement or disconnection
  2. Local anesthetic toxicity
  3. Delayed wound healing
11
Q

What are some advantages to wound soaker catheters?

A
  1. Technically simple
  2. Consistent and prolonged analgesia
  3. Decreased need for systemic analgesics
12
Q

What are the indications for a bier block?

A

Distal extremity procedures

13
Q

What are some advantages of a bier block?

A
  1. Simple and reliable

2. Minimal blood loss and clear field

14
Q

What is the procedure for a bier block?

A
  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
Q

What are some IVRA complications?

A
  1. Pain
  2. Ischemia/nerve injury
  3. Limb swelling
  4. Hematoma
  5. Local anesthetic toxicity
16
Q

What are indications for a retrobulbar block?

A
  • Enucleation
  • Eviscceration/prosthesis
  • Intraocular surgery
17
Q

What nerves are effected in a retrobulbar block?

A

CN III, IV, V, VI, ciliary ganglion

18
Q

What are the advantages to a retrobulbar block?

A
  1. Post-op analgesia
  2. Globe immobility during sx
  3. Decreased anesthetic and NMBD requirements
19
Q

What are potential complications of a retrobulbar block?

A
  • Retrobulbarr hemorrhage
  • Damage to optic nerve or extraocular muscles
  • Globe penetration
  • Intravascular injection
  • Intrathecal injection
20
Q

What is the preferred technique for a retrobulbar block?

A

Interior-temporal palpebral

21
Q

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

A

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

22
Q

What nerve does a maxillary nerve block affect?

A

Sensory branch of CN V

23
Q

What areas are anesthetised in a maxillary nerve block?

A

Maxilla and teeth/soft tissues, lateral nasal mucosa

24
Q

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

A
  1. Subzygomatic
  2. Maxillary tuberosity (intraoral)
  3. Infraorbital
25
Q

What does an infraorbital block provide anesthesia for?

A

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

26
Q

Where is an infraorbital nerve block placed?

A

Into the infraorbital foramen

27
Q

Is an intraoral or extraoral technique perfered in cats?

A

Extraoral

28
Q

What does an inferior alveolar block provide anesthesia for?

A

Mandibular teeth, rostral lower lip, intermandibular space

29
Q

Where is the injection given for an inferior alveolar block?

A

Medial aspect of mandible adjacent to mandibular foramen

30
Q

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

A

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

31
Q

What does a mental block provide anesthesia for?

A

Rostral lower lip only

32
Q

Where is the injection places for a mental nerve block?

A

Over palpable middle mental foramen, intra or extraorally

33
Q

What does an cervical paravertebral block provide anesthesia for?

A

Entire thoracic limb including the scapula and shoulder joint

34
Q

Which nerves are effected in a cervical paravetebral block?

A

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

35
Q

Are cervical paravertebral blocks commonly used?

A

No, very technically difficult

36
Q

What does a brachial plexus block provide anesthesia for?

A

Thoracic limb below them elbow

37
Q

Which nerves are effected in a brachial plexus block?

A

Suprascapular, musculocutaneous, radial, medial, and ulnar

38
Q

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

A

Yes, but ultrasound can be used

39
Q

What is a RUMM block used for?

A

Anesthesia of the distal thoracic limb including the carpus

40
Q

Which nerves are effected by a RUMM block?

A

Radial, ulnar, median, and musculocutaneous

That’s what RUMM stands for…..

41
Q

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

A

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

42
Q

T/F: Declaws are illegal in some places.

A

True

43
Q

What drug is used for declaw blocks?

A

Bupivacaine

44
Q

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

A

True

45
Q

Pelvic limb blocks anesthetize what?

A

Pelvic limb distal to the mid-femur

46
Q

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

A

True

47
Q

What are some indications for using an intercostal block

A

Thoracotomy, rib fractures, thoracic procedures, etc

48
Q

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

A

False- the VANs run along the caudal aspect

49
Q

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

A

True

50
Q

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

A

Down, because gravity. At least 20 min after injection

51
Q

Where are epidurals most commonly places in small animals?

A

L-S space

52
Q

Should epidurals be performed on awake animals?

A

No, heavy sedation or anesthesia is required

53
Q

What are two options for administering an epidural?

A
  1. Single injection

2. Indwelling catheter

54
Q

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

A

True- sternal is preferred

55
Q

What is the loss of resistance technique for epidurals?

A

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

56
Q

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

A

No- use saline or the epidural drug

57
Q

What is the hanging drop technique for eipdurals?

A

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

58
Q

What principle does the hanging drop technique work on?

A

The epidural space being subatmospheric pressure

59
Q

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

A

Large

60
Q

Are nerve locators commonly used in epidurals?

A

No

61
Q

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

A

True- risk for sympathetic blockade especially with LA drugs

62
Q

What volume will be sufficient to reach L1?

A

0.2 mL/kg

63
Q

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

A

True- usually bupivicaine and morphine

64
Q

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

A

True- may produce anesthesia in the thoracic wall/limbs

65
Q

What are some complications of an epidural injection?

A
  1. Intrathecal injection
  2. Neural damage/toxicity
  3. Infection
  4. Hypotension
66
Q

What are some complications of epidural opioids?

A

Urinary retention and puritis (uncommon)