Ex 3 - AC for ruminants, camelids, etc

Question 1

Main considerations:

Answer 1

• salivation
• regurgitation and aspiration
• bloat (rimem tympany)
• compromised pulmonary fxn
• size (myopathies and neuropathies)
• temperament

Question 2

Salivation

Answer 2

50-100L/day (cattle), 6-16 L/day (sheep) –> A LOT!

• difficult to intubate
• aspiration/obstruct airway

Question 3

Why are anticholinergics controversial for use to dec saliva?

Answer 3

Can make saliva more viscous

Question 4

Regurgitation

Answer 4

Built to regurgitate! Need to keep the larynx higher than rumen

rumen < larynx > mouth

Fast them, 24-48 hr off-feed

Question 5

Why do you want to keep ETT inflated during extubation??

Answer 5

Squeegee effect!

Question 6

Bloat

Answer 6

Recumbency/restraint/GA –> decreases eructation

Impacts respiratory and CV system

• decreases lung volume, compliance
• dec PaO/hypoxemia
• dec venous return

Question 7

Pulmonary function

Answer 7

Hypoventilation is common

V/Q mismatch

IPPV recommended

Question 8

Size

Answer 8

Same as horses - they are large!

Increased risk for myopathies and neuropathies

Padding and positioning important

Question 9

Temperament

Answer 9

Calm and stoic

Tolerant of physical restraint
- well-suited for standing procedures

Question 10

3 sites for IV injection

Answer 10

jugular, tail, auricular

Question 11

2 sites for IM injection

Answer 11

neck and shoulder

• avoid hind limb/meat production

Question 12

Catheter size and location

Answer 12

12-16 G, 14 cm long

• Local block (skin and SQ)
• Pilot hole with blade (full thickness)

Question 13

Intubation

Answer 13

Visual (large adult cattle)

Visual/laryngoscope; long blade +/- stylet (sheep, goat, calves)

Question 14

Drugs used in FA

Answer 14

Very FEW sedatives, anesthetic, and analgesics approved for use –> we use off-label

**NEED to know withdrawal times

Question 15

Website for withdrawal times

Answer 15

www.farad.org

Question 16

3 anesthetic techniques

Answer 16

1. Manual restraint with or w/out sedation and/or local anesthesia –> preferred method
2. GA using injectable only
3. Induction w/injectable anesthetics, followed by intubation and maintenance w/inhalants

Question 17

Xylazine

Answer 17

• sedation +/- recumbency (dose-dep)
• Ruminants more sensitive than horses
  Goat > sheep > cattle
• ABORTION in late pregnancy
• not approved for FA
• antagonist available (tolazoline, yohimbine0

Question 18

Should you use xylazine in sheep?

Answer 18

No - avoid use in sheep!

• activates pulmonary intravascular macrophages (PIM)
• hypoxemia, pulmonary hemorrhage/edema
• decreases pulmonary compliance

Question 19

Benzodiazepines

Answer 19

Good sedation for calves/small ruminants

Minimal CV depression

Question 20

Local anesthetics

Answer 20

Sheep very sensitive to toxic effects

Question 21

Opioids

Answer 21

Very few studies in ruminants

Efficacy is questionable

Most commonly used= morphine and butorphanol

Question 22

Ket-stun

Answer 22

Add ketamine at sub-anesthetic doses –> patients are “stunned” and oblivious to surroundings –> very good analgesic

Question 23

Ket-stun –> what combo of drugs is it?

Answer 23

Butorphenol, Xylazine, and Ketamine

Duration ~ 45 mins

Question 24

Induction agents

Answer 24

1. Ketamine
   * in combo w/ xylazine, diazepam or GG
2. Propofol
   * risk of apnea if not titrated carefully
3. Guaifenesin
   * mm relaxation, most used in cattle

Question 25

Arterial BP in cattle

Answer 25

Generally HIGH during anesthesia and recumbency

Question 26

Recovery

Answer 26

- quiet, calm environment - padded while in recumbency - keep ET tube with cuff inflated - prop animal into sternal recumbency - Extubate WITH cuff inflated

Question 27

SAC - general

Answer 27

Spit/kick Difficult to assess clinical status Body weight evaluation difficult (lots of fiber!)

Question 28

SAC - Catheter placement

Answer 28

High on neck * more superficial/thicker skin * away from carotid a.!!! At the 6th cervical vertebrae level * medial to transverse process * thinner skin, closer to carotid a. (be cautious!) *Jug v. not readily visible, thick skin requires pilot hole, changes in position may cause catheter to kink

Question 29

SAC - intubation

Answer 29

lidocaine may help Positioning is important --> "nose to sky" **Protect eyes**

Question 30

SAC - Recovery

Answer 30

* Lavage nasal passages to remove regurgitated material * keep ETT as long as possible * watch for signs of dorsal displacement of soft palate - extend head & neck - stimulate swallowing

Question 31

Swine - general

Answer 31

* Tremendous size variation - dose difference * Venous access is VERY difficult - Use ear veins * IM injections in neck muscle - need 1.5" needle or longer --> lots of fat you need to go through * Intubation is very difficult!

Question 32

Swine - Malignant Hyperthermia

Answer 32

* Heritable defect in sarcoplasmic reticulum - Excessive influx of Ca++ * HYPERmetabolic state - excess heat and CO2 production - inc O2 consumption, muscle rigidity

Question 33

Swine - MH Triggers

Answer 33

Halothane (or any potent inhaled anesthetic) Succinylcholine Other (stress, excitement?)