Pigs Flashcards

1
Q

Restraint Techniques for Pigs

A

o Hog board – same height as animal, 2/3 to full length
o Sling
o Lifting hind legs (smaller pigs)
o Snout snare – not comfortable, acts like tourniquet around nose, leave on only few min

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2
Q

IV Access in Pigs

A

challenging, lack of visible superficial veins

Marginal ear veins (auricular veins)
* Central auricular vessels usually arteries (like rabbits)

Lateral, medial veins outer surface of ear in larger pigs
* LJ: central dorsal auricular vein

Cephalic: blind, visualized in small pigs

Jugular cut down, can also use anterior vena cava

Mammary

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3
Q

IO Route

A

greater tubercle of humerus or trochanteric fossa of femur
* Rate of fluid administration limited in older pigs DT presence of fat, fibrosis of medullary canal

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4
Q

IM Injection Sites for Pigs

A

base of ear = thinner fat, tissues have better perfusion
 Preferred for immobilization

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5
Q

IM Injection Site Logistics - Pigs

A

Need adequate length needles so don’t inadvertently inject into fat
* Thick layer of subcutaneous fat, more so for potbellied pigs
* Adipose tissue layers in neck, rump particularly thick

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6
Q

Where to avoid for IM in pigs?

A

No thigh in growers – risk of abscess, needle breakage in edible tissue
* LJ Chp 38: recommended to inject in hamstring muscles just above hock or caudal portion of biceps femoris DT lower fat
* Gluteal ‘ham’ muscle not recommended: m inflammation, fibrosis

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7
Q

SQ Inj in Pigs

A

smaller, mini pigs
 Very tight connective tissue
 Lateral cervical region: flap of tissue available

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8
Q

Pigs - Resp

A

obligate nasal breathers; short, narrow airway with long soft palate

Tracheal bronchi!

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9
Q

Pigs - GIT

A

acidic stomach, pH 1.5 to 2.5 – better, faster, more predictable absorption of orally administered drugs, prone to perioperative vomiting

Very well developed torus pyloricus

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10
Q

Other Sedative Routes in Pigs

A

IN: midaz 0.2-0.4mg/kg = reliable sedation within 3-4’; ketamine 15mg/kg + climazolam 1.5mg/kg + azaperone 1.0mg/kg for castration = less effective ax vs IM but minor temp loss, shorter recovery time

o IP: requires specific training, risk of bad consequences if improperly performed

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10
Q

Pigs - GIT

A

acidic stomach, pH 1.5 to 2.5 – better, faster, more predictable absorption of orally administered drugs, prone to perioperative vomiting

Very well developed torus pyloricus

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10
Q

Pigs - CV

A

Prolonged QT Interval

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11
Q

Fasting Times in Pigs

A

Minimum 12h food
o Prolonged gastric emptying DT roughage, risk of Perioperative nausea/vomiting

o Elective GI/abdo sx: 24-48hr to empty large bowel, H2O 4-6hr if stomach/small bowel sx
o Neonates: 3h
o Remove edible bedding for 2-3d

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12
Q

Sedation in Pigs

A

Ketamine is your friend

Best combined w/ adjunctive agents to improve SkM relaxation, analgesia, decrease ket dose
o Much more resistant to a2s compared to ruminants
 In general don’t become very sedate off opioids, alpha a2

Tramadol = less respiratory depression in pigs than other opioids

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13
Q

Which pigs generally need higher doses of sedation?

A

Yucatan, Yorkshire pigs, VPB

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14
Q

Azaperone

A

butyrophenone neuroleptic, safe for IM
 Approved for use in swine
 IV contraindicated, +/- excitation
 Sedative + LA for minor sx procedures, premedicant with anxiolytic properties
 Effects = dose dependent

 Large boars: do not exceed 1mg/kg to decrease risk of priapism

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15
Q

a chloralose

A
  • Mixed effects of dose-dependent CNS excitation, depression
  • CV stability, lack of BR depression, poor analgesia when used alone
  • Poor solubility
  • Slow onset (15-20’)
  • Causes metabolic acidosis, hyperreactivity to auditory stimulation, peritonitis, adynamic ileus
  • Loading dose 40mg/kg IV, CRI 10mg/kg/hr
  • CMV recommended: prevent hypercapnia, respiratory acidosis
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16
Q

Endotracheal intubation in Pigs - when/why

A

o Recommended for px > few min, dorsal recumbency – hypoxia, hypercapnia, airway obstruction
o Resp depression = significant risk bc need for heavier sedation to decrease stress level, high work of breathing by narrow upper airway
o Prone to laryngospasm, fluid tends to accumulate in pharyngeal region under GA

17
Q

Anatomic Challenges Assoc with Airway Management in Pigs

A

 Thick tongues
 Long, narrow oropharyngeal spaces
 Elongated soft palate
 Pharyngeal diverticulum: 3-4cm in adults, 1cm in piglets – protrudes from wall of pharynx, above esophagus
* If get stuck in diverticulum – pneumediastinum
 Angle btw floor of lateral ventricle, trachea, cd to opening of larynx = obtuse
 ETT: R endobronchial intubation if inserted too far
* R cranial LL branches off very early – pre measured tube TRACHEAL BRONCHI
 Delicate laryngeal mucosa, prone to irritation/injury (hematoma, rupture, generalized laryngeal edema)

18
Q

Maintenance of GA in Pigs

A

o All current inhalants used safely, effectively in pigs - MH triggers (Halothane&raquo_space;> iso)

N2O: max concentration N2O in pigs 75% with 25% O2
 50-66% more common clinically

19
Q

Xenon Maintenance of GA in Pigs

A

research, inert gas that not harmful to environment
 Systemic hemodynamic stability, analgesia
 MAC 119% intubated pigs, does not trigger MH
 Production = cost-prohibitive, requires low FGF rates with xenon-recycling system

20
Q

Telazol or Ketamine in Pigs

A

rough recoveries  excessive paddling, multiple attempts to stand, hypersalivation, frequent vocalization, hyperthermia
* Eliminated more slowly than other species
* Tiletamine longer DOA vs zolazepam

21
Q

Triple Drip in Pigs

A

Triple drip: 5% solution of dextrose in water w/ 50mg/mL guaifenesin, 1-2mg/mL ket, 1mg/mL xyla
 Infusion rate 2.2mL/kg/hr

22
Q

Opioids

A

Severe Resp Depression in Pigs

Excitement if non painful

Pupillary Constriction

23
Q

BIS in Pigs

A

poor correlation with ax depth, may not predict changes in BP or HR during sx

24
Q

Monitoring in Pigs

A

Most reliable method for assessing depth in pigs: m relaxation –> jaw tone laxity, absence of gross movement IRT pinch or stimulus at coronary band
 Also reliable: palpebral, corneal reflexes
 Not reliable: ocular, pupillary reflexes esp if atropine, ket in protocol

25
Q

Blood Transfusions in Pigs

A

usually littermates, close relatives DT 16 recognized porcine blood groups

26
Q

BP Treatment in Pigs

A

Dopamine = most effective inotropic agent in pigs!

  • 15mcg/kg/min increased CI by 18%, improved GI BF by 33% in septic pigs
  • Piglets: better improved BF to heart, SI vs dobutamine
27
Q

FiO2 in Pigs

A

 Pulmonary shunt fraction depends on FiO2, lower shunt fraction with FiO2 0.4 vs 0.6, 0.8

28
Q

Porcine Recovery

A

o Pen, cage lined with soft padding to preclude injury
o 20-25* to minimize hypothermia +/- thermal blanket +/- heat lamp
o If early extubation, high risk for hypoxemia DT laryngospasm
 Steroids, diuretics prophylactically prior to extubation
 Phenylephrine spray on larynx  vascular congestion, laryngeal edema
o Surgical incisions: do not house with other animals, will cannibalize wounds
o Behavior parameters to monitor pain: agitation, running, rooting

29
Q

Main Risks Assoc with Swine Recovery?

A

Severe airway obstruction difficult to tx: difficult to restrain, reintubate

Extension of head can complicate air upper airway obstruction
–Also do not want to extend head for tube placement

Dorsal displacement of soft palate = airway obstruction, suffocation

OBLIGATE NASAL BREATHERS

30
Q

Epidurals in Pigs

A

6 or 7 lumbar vertebrae
* SC terminates with conus medullaris btw sacral vertebrae 2 and 3 - SAS not easily penetrated in pigs

Consider US guidance for LS epidurals DT amt of fat (L6-S1)

  • Measurement of distance from external occipital protuberance to 1st Co vertebrae may allow for more precise dosing of epidural injections DT differences in number of thoracic, lumbar vertebrae
31
Q

Examples of Epidural Protocols in Pigs

A

For max distribution of drug into spinal canal, morph + saline = 1mL of solution for pigs with vertebral length of up to 40cm, +1.5mL saline added for Q additional 10cm vertebral length

To achieve blockade to T10 in pigs <65kg:
 0.8mL/10cm 40-69cm
 0.9mL/10cm 70-79
 1mL/10cm 80-99

32
Q

Examples of Epidural Protocols in Pigs

A
33
Q

Seizure Dose of Lidocaine in Pigs

A

24mg/kg

34
Q

Malignant Hyperthermia

A

Inherited autosomal recessive DO –> single amino acid mutation in ryanodine receptor type 1 (RYR1) assoc with calcium channels in skeletal m

When triggered, muscle not able to control Ca efflux from inside SR

Massive amt of Ca released from SR into cells, calcium activation of myosin ATPase causes excessive muscle contracture, release of heat

Cell metabolism increased: requires anaerobic, aerobic respiration = increased CO2, H+, lactate; decreased venous oxygen content

35
Q

MH Triggers

A

any type of stress
o All commonly used VAs, halothane
Only one incidence of iso induced MH
o Depolarizing NMBAs (succinylcholine)

36
Q

Pigs most predisposed to MH?

A

–Genertic testing now available
have high ratio of muscle to total body mass, rapid growth
o Pietran, Landrace, Spotted, Large White, Hampshire, Poland-China

PPLLHS

37
Q

MH Presentation

A

increased body temp
m rigidity
tachycardia
tachypnea,
extreme hypercapnia (ETCO2 >70 mm Hg)
hypoxemia
metabolic acidosis
SNS activation with increased catecholamine plasma concentration
high serum Mg, Ca, Phos, K

38
Q

Sequela of MH

A

o As progresses, cell metabolism unable to meet demands –> membrane integrity compromised –> increased d permeability (edema)
o Cardiac ischemia, decreased coronary perfusion pressure DT increased m metabolism
o Arrhythmias: decreased CO, cardiac failure with related hypotension
o Also myoglobinuria, renal failure

39
Q

Prognosis of MH?

A

usually poor once episode initiated in spite of immediate, aggressive treatments

40
Q

MH Tx/Management

A
  1. DC inhalant, ventilate 100% oxygen
     Preferably change machine, at least different rubber components (hoses, bag)
     Hyperventilate
  2. Active cooling = alcohol baths, ice packs around large vessels, fans, rectal lavage with ice water
  3. Dantrolene
41
Q

Dantrolene

A

IV 1-5mg/kg
 Skeletal m relaxant, inhibits excessive leak of calcium by RYR1
 Prevent, tx MH
 Prevention: 2-5mg/kg PO 6-10hr prior to induction
 Highly lipophilic, poorly water soluble

42
Q

Azumolene

A

30x more soluble than dantrolene, reverses m contractive in pigs by decreasing opening rate of RYR1, w/o changing Ca uptake into SR