VMED 5267 - Ruminant
Anesthesia
1.- Continuous secretion
- Low surface tension compared to water = Promotes formation of foam
- Source of upper airway obstruction under anesthesia: What are issues
that can arise from saliva secretion in ruminants under GA?
2.Fermentation
- 30L of gas production in cattle
- Bloating = Increase in intra-abdominal pressure
Regurgitation
- Rumen full of liquid, does not empty completely
- Active (light anesthesia) or passive (deep anesthesia) regurgitation
- Risk of aspiration: What are potential issues that can arise from the
rumen in ruminants under GA?
3.- Reflex airway closure
- Bronchospasm
- Destruction of type II pneumocytes and pulmonary capillary lining cells
- Pulmonary edema and hemorrhage: What are potential outcomes of
aspiration in ruminants?
4.- Small tidal volume = Small (lobulated) lungs
- High respiratory rate
- Flatter and vertical diaphragm
During recumbency abdominal viscera pushes against diaphragm
- Decreases functional residual capacity (FRC)
- Decreased lung compliance, tidal volume, and minute ventilation
- Increased ventilation/perfusion (V/Q) mismatching
- Hypoxemia: What are specific considerations of the respiratory system
that can cause anesthetic complications?
5.Compression of vena cava during recumbency
- Decreased venous return
- Decreased cardiac output and blood pressure
- Most affected in dorsal recumbency: What impact can GA have on the
cardio- vascular system of ruminants?
6.- Neuromyopathy
- 10-cm thick high-density foam pad
Dorsal recumbency
- Balanced squarely with gluteal areas bearing equal weight
- Limbs flexed and relaxed
1/
6
, VMED 5267 - Ruminant
Anesthesia
Lateral recumbency
- Automotive inner tube placed under elbow of dependent forelimb and
pulled anteriorly
- Front and hindlimbs elevated and parallel to the table
- Head and neck extended
- Protect eye: Positioning considerations for large ruminant patients?
7.- Adult large ruminants 24-48 hr.
- Small ruminants 12-24 hr.
- May not prevent regurgitation nor bloating
- Withhold water 12-24 hr.: How long should ruminants be fasted pior to
GA?
8.- Jugular vein
- Auricular vein (cattle): IV catheter sites for ruminants?
9.- Always recommended
- Deep plane of anesthesia during intubation
- Hand guided +/- stylet guide
- Difficult airway: Narrow and long oral cavity, Thick tongue: What are
features of endotracheal entubation of cattle?
10.- Always recommended
- Deep plane of anesthesia during intubation
- Difficult airway: Narrow and long oral cavity, Thick tongue
- Long blade laryngoscope
- Stylet: What are features of endotracheal entubation of small ruminants
11.- Acepromazine
- A2 agonists
- Benzodiazeqpines
- Butorphanol: What are potential sedatives for ruminants?
12.4-8 hours duration
- Blockade of dopaminergic receptor
in basal ganglia
- Mild tranquilization/calming effect
- Vasodilatory effect (blockade of
z1 receptors)
- May increase risk of regurgitation
- Penile prolapse in bulls
**Not commonly used = no antagonist: Effects of acepromazine in ruminants
13.- Central (presynaptic) and peripheral (postsynaptic) adrenoceptors
2/
6
Anesthesia
1.- Continuous secretion
- Low surface tension compared to water = Promotes formation of foam
- Source of upper airway obstruction under anesthesia: What are issues
that can arise from saliva secretion in ruminants under GA?
2.Fermentation
- 30L of gas production in cattle
- Bloating = Increase in intra-abdominal pressure
Regurgitation
- Rumen full of liquid, does not empty completely
- Active (light anesthesia) or passive (deep anesthesia) regurgitation
- Risk of aspiration: What are potential issues that can arise from the
rumen in ruminants under GA?
3.- Reflex airway closure
- Bronchospasm
- Destruction of type II pneumocytes and pulmonary capillary lining cells
- Pulmonary edema and hemorrhage: What are potential outcomes of
aspiration in ruminants?
4.- Small tidal volume = Small (lobulated) lungs
- High respiratory rate
- Flatter and vertical diaphragm
During recumbency abdominal viscera pushes against diaphragm
- Decreases functional residual capacity (FRC)
- Decreased lung compliance, tidal volume, and minute ventilation
- Increased ventilation/perfusion (V/Q) mismatching
- Hypoxemia: What are specific considerations of the respiratory system
that can cause anesthetic complications?
5.Compression of vena cava during recumbency
- Decreased venous return
- Decreased cardiac output and blood pressure
- Most affected in dorsal recumbency: What impact can GA have on the
cardio- vascular system of ruminants?
6.- Neuromyopathy
- 10-cm thick high-density foam pad
Dorsal recumbency
- Balanced squarely with gluteal areas bearing equal weight
- Limbs flexed and relaxed
1/
6
, VMED 5267 - Ruminant
Anesthesia
Lateral recumbency
- Automotive inner tube placed under elbow of dependent forelimb and
pulled anteriorly
- Front and hindlimbs elevated and parallel to the table
- Head and neck extended
- Protect eye: Positioning considerations for large ruminant patients?
7.- Adult large ruminants 24-48 hr.
- Small ruminants 12-24 hr.
- May not prevent regurgitation nor bloating
- Withhold water 12-24 hr.: How long should ruminants be fasted pior to
GA?
8.- Jugular vein
- Auricular vein (cattle): IV catheter sites for ruminants?
9.- Always recommended
- Deep plane of anesthesia during intubation
- Hand guided +/- stylet guide
- Difficult airway: Narrow and long oral cavity, Thick tongue: What are
features of endotracheal entubation of cattle?
10.- Always recommended
- Deep plane of anesthesia during intubation
- Difficult airway: Narrow and long oral cavity, Thick tongue
- Long blade laryngoscope
- Stylet: What are features of endotracheal entubation of small ruminants
11.- Acepromazine
- A2 agonists
- Benzodiazeqpines
- Butorphanol: What are potential sedatives for ruminants?
12.4-8 hours duration
- Blockade of dopaminergic receptor
in basal ganglia
- Mild tranquilization/calming effect
- Vasodilatory effect (blockade of
z1 receptors)
- May increase risk of regurgitation
- Penile prolapse in bulls
**Not commonly used = no antagonist: Effects of acepromazine in ruminants
13.- Central (presynaptic) and peripheral (postsynaptic) adrenoceptors
2/
6
