Anesthetic Considerations in Ruminants, Camelids and Swine Flashcards
(58 cards)
1
Q
ruminants
A
cattle, goats, sheep
2
Q
rumen anesthetic considerations
A
- salivation: aspirate, difficult intubation, etc
- regurgitation and aspiration
- bloat (rumen tympany)
- compromised pulmonary function
- size (myopathies and neuropathies)
- temperament: pretty good
3
Q
ruminant salivation
A
- 50-100L a day for cattle
- 6-16L a day in sheep
- causes difficult intubation (visualization): lower head and allow to drain
- risk of aspiration and airway obstruction
4
Q
how do you position a ruminant to prevent aspiration/issues because of salivation?
A
larynx higher than the oral cavity! lower head and allow to drain
5
Q
anticholinergics with ruminants?
A
controversial: decrease liquid part of saliva, but this makes it thicker and harder to remove. not usually used
6
Q
in what position do you induce and intubate ruminants?
A
induce and intubate in sternal, then position them
towels under the larynx
7
Q
T/F: you fast ruminants before anesthetic procedures
A
yes
8
Q
fasting protocol for ruminants
A
- 24-48 hours off feed for larger ruminants, smaller ones 12-18 hours off feed
- 8-12 off water? depends on weather. if hot, do not take off water
- decreases bloat, hypoventilation, V/Q mismatch
- lowers HR by 20%
9
Q
aspiration can be life threatening in ruminants. before intubation, what do you need to do?
A
- check anesthetic depth!! because you can stimulate regurgitation if not deep enough
- once intubated, larynx should be highest point
- keep ETT inflated during extubation!! used to bring food stuff out
10
Q
T/F: you should keep the ETT inflated during extubation of ruminants
A
true: will be used to bring food/stuff oout
11
Q
how does anesthesia affect the rumen?
A
- increases chance of bloat
- recumbency/restraint/GA: decreases eructation
- impacts respiratory and CV systems: decreases lung volume, compliance, PaO2/hypoxemia, venous return
12
Q
how does anesthesia affect pulmonary function of ruminants?
A
- hypoventilation is common
- V/Q mismatch: large ruminants
- respiratory pattern: increases respiratory rate and decreases tidal volume
- IPPV (mechanical ventilation) is recommended
13
Q
T/F: IPPV is recommended in ruminants
A
true
over time their PO2 drops
14
Q
does RR increase or decrease in ruminants under anesthesia?
A
increases, tidal volume decreases
15
Q
T/F: ruminants are good for standing procedures and restraint/local anesthesia
A
true. most procedures are performed standing, GA only when necessary
16
Q
where are IV injection sites for ruminants?
A
jugular, tail, auricular
17
Q
where are IM injection sites for ruminants?
A
neck, shoulder. avoid hind limb/meat production
18
Q
catheter parameters for ruminants
A
- 12-16 G, 14 cm long
- local block: skin and SQ
- pilot hole with blade for full thickness: their skin is super thick! want a big block thru skin completely so the catheter doesn’t drag
19
Q
a fancy angus adult cow is anesthetized for stifle arthroscopy. which of the following is a true statement:
a. intubation should be performed at a light plane of anesthesia
b. the larynx should be positioned higher than the mouth and rumen
c. ruminants don’t need to be fasted
A
b
20
Q
how do you intubate cattle?
A
need to feel for epiglottis and larynx; need team keeping mouth open
21
Q
how do you intubate sheep/goats/calves?
A
- visual/laryngoscope
- long blade +/- stylet: feed the tube over stylet
- check and make sure tube is in trachea!! if you don’t see it going in, it likely is in esophagus
22
Q
issues with anesthetizing ruminants
A
- drugs used in food animals are few
- very few sedatives, anesthetics and analgesics are approved for use in livestock
- withdrawal times too
23
Q
anesthesia techniques in ruminants
A
- physical restraint: with or without sedation. and local anesthesia
- general anesthesia using injectable anesthetics only
- induction with injectable anesthetics, followed by intubation and maintenance with inhalants
24
Q
what type of drug is xylazine?
A
alpha 2 agonist
25
xylazine use in ruminants
- dose dependent sedation and recumbency (careful)
- more sensitive compared to horses! 10x more
^ goat > sheep > cattle
- ABORTION IN LATE PREGNANCY! causes uterine contraction. use detomidine instead. it is oxytocin like
- antagonists are available: tolazoline, yohimbine
26
T/F: horses are more sensitive to xylazine than cows
false, other way around
goats are most sensitive , then sheep, then cattle
27
you are going to anesthetize a late term pregnant cow for a C section. your assistant draws up xylazine as she knows it is commonly used in ruminants. what do you tell her?
xylazine causes abortion in late pregnancy as it has oxytocin like characteristics: causes uterine contraction. use detomidine instead
28
what antagonists are available for xylazine ?
tolazoline, yohimbine
29
in what species do we avoid alpha 2s (esp xylazine) in?
sheep! and goats
30
why do we avoid xylazine in sheep?
- activates pulmonary intravascular macrophages: PIM
- hypoxemia, pulmonary hemorrhage/edema from influx of inflammatory agents
- decreases pulmonary compliance
31
what drug can you NOT use in sheep?
xylazine!! activates pulmonary intravascular macrophages which create huge inflammatory response and decrease pulmonary compliance
32
benzodiazepines in ruminants?
- good sedation for calves/small ruminants
- minimal CV depression!
33
local anesthetics in ruminants?
- sheep very sensitive to LA toxicity!! need to calculate what toxic dose is
34
opioids in ruminants?
- very few studies done
- limited efficacy?
- morphine, butorphanol, and hydromorphone most commonly used
35
what is Ket-Stun?
- special combination for standing sedation in cattle, puts them in a dissociative state
- Butorphanol, Xylazine, Ketamine all given IM
- duration: 45 mins
- cattle appear to be awake, but are minimally responsive to stimuli
36
what are the drugs and their doses of Ket-Stun in cattle?
- butorphanol: 0.025 mg/kg
- xylazine: 0.05 mg/kg
- ketamine: 0.1 mg/kg
all IM
37
what is Johnson's cocktail?
- IM protocol for sedation/anesthesia standing in small ruminants
- butorphanol, xylazine, ketamine
38
drugs/dose of Johnson's cocktail
- butorphanol: 10mg / (1 mL)
- xylazine: 100 mg / (1mL) mixed together
- ketamine: 1000mg (10mL)
dose 0.02 sheep and 0.06 in alpaca. repeat to 1/4 to 1/2 IV if needed
39
what induction agents are used in ruminants?
- ketamine: in combo with xylazine, benzo or GG
- propofol or alfaxalone: risk of apnea if not titrated carefully
- guaifenesin (adjunct): muscle relaxation, most used in cattle
40
injectable vs inhalant anesthetic in ruminants
- duration
- elimination
- ambient air vs oxygen
- ventilatory support
- degree of muscle relaxation
41
monitoring during GA
- eye signs
- HR, RR
- muscle relaxation, response to surgical stim
- arterial BP: cattle tend to have increased BP: MAP of 60 is rlly low for cow. need to have 80s +, def > 70!
42
what is unique about blood pressure in cattle?
- they tend to have increased BP: MAP of 60 is rlly low for cow. need to have 80s+, >70 definitely
43
MAP =
CO x SVR
44
what do we want to maintain cattle MAP at?
> 70 mmHg
45
ruminant recovery
- usually quiet, calm with little struggling
- keep padding
- maintain ET tube with cuff inflated
- prop animal into sternal recumbency
- extubate with cuff inflated
46
which is NOT an appropriate sedation protocol for a 10 year sheep with suspected pneumonia?
a. midazolam and morphine
b. xylazine and butorphanol
c. diazepam and butorphanol
b: if susp pneumonia, don't want to give alpha2s! increase edema and congestion
you want to avoid xylazine in sheep!
47
what are the south american camelids? what are some challenges associated with them?
llama, alpaca, guanaco, vicuna
- behavior, catheter, intubation, positioning recovery
- difficult to assess clinical status because they are prey species and hide disease well.
- esp bc they are fluffy! can be really emaciated and you wont know without getting hands on them
- spit and kick
48
where do we place catheters in SAC?
- high on neck! more superficial/thicker skin, and away from carotid artery
- at the 6th cervical vertebrae level: medial to transverse process, thinner skin and closer to carotid a
49
if you want to avoid the carotid artery when placing a catheter in a SAC, where do you place it?
high on neck
50
challenges of catheter placement in SAC
- jugular vein not readily available
- thick skin requires pilot hole
- changes in position may cause catheter to kink
- venous blood is bright red: no way of knowing whether venous or arterial blood
51
anesthetic considerations in SAC
- similar to ruminants: regurgiation/salivation/aspiration
- 3 compartment stomach
- fast for 12-24 hours/water 8-12 hours
- risk of passive regurgitation
- tympany: C1: decreased venous return and FRC
52
in what species can you hear tympany in when under GA?
SAC: hear in C1: decreased venous return and FRC
53
intubation of SAC is hard. what do we do to help make it easier?
- stylet?
- lidocaine
- positioning: nose to sky: stretch out neck, stylet 1st and tube over it
- mouth < larynx > stomach
- protect eyes!!! lift neck up, lube eyes to prevent ulcers
54
T/F: SAC should have their stomach higher than the mouth and larynx to help offset tympany
false: larynx still should be highest point
55
SAC recovery
- lavage nasal passages to remove regurgitated material
- maintain ET tube as long as possible
- watch for signs of dorsal displacement of soft palate: extend head and neck and stimulate swallowing
don't take your eyes off them! sharp teeth and can chew tube in mouth
56
swine anesthesia considerations
- tremendous size variation, so doses differ
- venous access VERY difficult! ear veins
- IM injections in neck muscle is best bet: behind ears, long needle: 11/2 inch needle or longer
- intubation VERY difficult. curves down and thten trachea turns
57
malignant hyperthermia
- heritable defect in sarcoplasmic reticulum in skeletal muscles
- excessive influx of calcium in to mm
- hypermetabolic state
- excessive heat and CO2 production
- increased O2 consumption and muscle rigidity. usually fatal
58
triggers for malignant hyperthermia
- halothane, or any potent inhaled anesthetic
- succinylcholine: not used anymore
- stress, excitement
txt only available in human hosp
