What are the goals of sedation? (6)
- decrease stress
- chemical restraint (esp in aggressive and fractitous animals- safety)
- muscle relaxation
- less induction and maintenance drugs
- smoother recovery from general anesthesia
________ is usually not a necessary part of the anesthetic plans in ruminants.
Describe how neuroleptanalgesia is used in ruminants.
- [combine opioids and sedatives to enhance effects and prolong the duration of sedation]
- butorphanol or morphine
What are the cardiovascular and pulmonary effects of alpha-2 agonists? (5)
- bradycardia and decreased CO
- decreased inotropy
- hypertension (very transient with xylazine, longer with dexmedetomidine)
- respiratory depression
- SHEEP: macrophage activation and pulmonary edema (don't use in sheep or goats)
What are side effects of alpha-2's (other than CVS/ pulmonary)? (4)
- decreased insulin production/ increased plasma glucose
- increased urine production
- GI stasis
What is important to remember about using alpha-2 agonists?
analgesia does not persist when sedation is gone--> must use opioids or another analgesic as additive
Describe the effects of acepromazine and why they occur. (2)
- sedation due to dopamine blockade
- vasodilation due to alpha blockade
What are the CVS and pulmonary effects of acepromazine?
- decreased BP d/t vasodilation
- +/- HR increased
- no respiratory changes
Describe the use of midalzolam and the pros of using this drug over other benzos.
- muscle relaxation
- less CVS and respiratory depression than diazepam
Midazolam should not be used in __________.
What are the effects of butorphanol when used alone?
Short-term anesthesia can be accomplished by administration of what drug combinations? (5)
- ketamine- midazolam
Describe the use of guaifenesin-ketamine mixtures in ruminants.
- "double drip method" (titration)
- titration of this combination provides reliable sedation and recumbancy
- minimal CVS and pulmonary side effects
Describe the use of ketamine-midazolam in ruminants.
- patient will be recumbent
- 15-20 minutes of general anesthesia
Describe the use of propofol in ruminants.
- rapid- acting and ultra-short duration (immediate unconsciousness and recumbency)
- use with caution- apnea and hypotension
Describe the use of xylazine- ketamine mixture in ruminants.
- delivered IM
- short-term anesthesia
- use low doses (high doses associated with profound respiratory depression)
_________ has been associated with telazol administration.
Describe intubation of ruminants.
adult cattle and camels- place arm in mouth, digitally palpated cartilages of the pharynx, slide tube under your arm and place it in the larynx
What are important factors of managing general anesthesia in ruminants. (2)
- head positioning- hang head so saliva/ etc flows out of mouth
Describe monitoring during anesthesia in ruminants.
- pulse palpation (auricular artery)
- invasive arterial BP
- pulse ox
- arterial blood gases
Describe recovery of camelids from general anesthesia.
- once a camelid is extubated, place them sternally with head elevated and place a nasopharyngeal tube so they can breath (obligate nasal breathers)
- [all ruminants- poll of the head at the highest point]
What are behavioral cues of pain in ruminants?
- weight loss
- decreased milk yield
- tachycardia/ tacyhpnea
- plasma cortisol
- turing toward site of stimulus
- restlessness/ pacing
- reluctance to move
- dull and decrease appearance
- licked more by other cows
How did meloxicam administration before castration affect post-weaning calves?
reduced incidence of respiratory disease at the feedlot
Describe the pain scoring system for ruminants.
- lying down quietly, looking depressed and sedated= 1
- restless with intermittent vocalization or bruxism= 2
- continuous vocalization and violent muscular activity= 3
What are the 5 basic mechanisms of abdominal pain?
- distention of a hollow viscous
- traction or inflammation of the peritoneum or mesentery
- smooth muscle spasm
Describe abdominal pain perception.
- abdominal viscera are sparsely innervated and lack specific pain receptors
- difficult to localize visceral pain
- localized visceral lesions rarely cause pain, so in general visceral pain indicates diffuse disease
What are the pros of using NSAIDs for analgesia?
- not as potent as opioids, but longer-lasting
- provide peripheral and centrally-mediated analgesic effects
Where do you block for dehorning in goats?
cornual branch of the zygomaticotemporal and cornual branch of the infratrochlear nerves
Where do you block for dehorning in cattle?
cornual branch of the zygomaticotemporal nerve [blocks the horn base and the horn]
Where do you perform a caudal epidural?
- space b/w S5 and Caudal 1
- or between caudal 1 and 2
Where can the lumbosacral space palpated in young cattle and small ruminants?
craniodorsal iliac crests, spinal process of last lumbar veretebra, medial sacral crest