Swine and Ruminant Anesthesia

True or False An anticholinergic is an essential component of premedication in ruminants.

False

True or False It is common for anesthetized ruminants to hypoventilate

False

Positioning the head of an anesthetized ruminant with the pharynx higher than the mouth helps to prevent

aspiration

ketamine-xyalzine

○xylazine •0.1-0.2 mg/kg IM or •0.05 -0.1 mg/kg IV •deep sedation often recumbency •butorphanol = 0.1-0.2 mg/kg for better analgesia and muscle relaxation ♦ketamine = 2 mg/kg IV ☻Et intubation can be performed soon after xylazine and before ketamine •whenever possible do this way, as ketamine produces copious salivation or an inability to swallow the normal saliva ○hypoxia reported -supplemental oxygen is recommended

use of anesthetics for food animals

♣most anesthetics on extra label use basis ♠if a residue is found an individual can be prosecuted

TKX

•telazol ◘ketamine ♦xylazine used to sedate pigs via IM

"Double drip" contains which two drugs?

Guaifenesin and Ketamine

drug administration in swine

◘IV best made into auricular vein -the ear veins not suitable for injecting large volumes ◘surgical cut-down of jugular vein necessary ○cephalic vein -FOR IM injection neck muscles •in large pigs (or pot-bellied pig) use long needle •rear limb to avoid injecting into the fat in the neck

swine anesthesia

◘can be extremely difficult to control ◘in general good subject for GA -not become violently excited -does not seem to increase the epinephrine release -recovery usually calm

endotracheal intubation

◘patient airway ◘prevents aspiration ◘mouth gag ◘tracheal guide tube -in sheep, goats, calves &llamas •long laryngeal blade and stylet

xylazine

◘potent hypnotic , deep sedation •popular as premedicant •dose dependent severe CV effect ☻sheep - hypoxemia , hypercapnia & pulmonary edema ☻cattle = 0.01/0.1 mg/kg IV(1/10th of equine dose) ☻llamas= 0.2-0.3 mg/kg IV provides recumbency ☻cattle recumbency for 1 hour= 6

more monitoring

☻HR, BP, mucous membrane color and CRT ☻direct blood pressure measurement through catheterizing the auricular artery in cattle ☻ECG ☻pulse oxietry ☻arterial blood gas analysisf

anesthetic induction

♣ketamine -ketamine alone will not cause seizures in cattle but the quality of induction is poor •muscle rigidity and excessive salivation •used in combination with other sedatives •increased HR, BP, CO

preanesthetic preparation

♦fasting and water deprivation •fasting neonates are not recommended •do a physical exam •lab evaluation •stabilize animal's physiology in debilitated animals

Recovery of Pig

♦keep the pig in warm environment -lack of body hair ♦adequate post-operative pain relief •close observation to the upper airway obstruction

ketamine-diazepam

♦less CV depression •can be used for induction in xylazine premedicated animals -in calves and small animals ♦0.25 mg/kg of diazepam & 5 mg/kg ketamine ♦+ butorphanol 0.1-0.2 mg/kg IV ♦approximately 15 min of anesthesia

protocol examples

♦premed:xylazine @ 0.1 mg/kg •induction:ketamine @ 2 mg/kg ♦premed:xylazine @ 01 mg/kg •induction:diazepam @ 0.05 & ketamine @ 2 ♦premed:y=xylazine-butorphanol @ 0.05 & 0.02 •induction:ketamine @ 2 ♦premed:xylazine ± butorphanol @ 0.05-0.1 & 0.02 •induction:guaifenesin followed by ketamine bolus @ 100(G) or to "effect"& 1 for (K)

propofol

♦small ruminants or calves •5-6 mg/kg IV produces 4-9 min. of anesthesia ♦maintenance of anesthesia via CRI ○primary limiting factors •expense •volume

anesthetic induction of swine

♫balanced anesthetic technique ♦alpha 2 with dissociative -much less sensitive to alpha 2 ♦BDZ with dissociative ♦alfaxalone, propofol etc ♦opioids can be added

danger of regurgiation

-aspiration: asphyxia and death within 24 hours -regurgitation can be minimized by •starvation •water deprivation •elevating the neck and positioning the head sloped down •stomach tube

anesthetic maintenance of pig

-maintenance best with inhalation anesthesia -isoflurane, halothane, sevoflurane, desflurane ◘halothane least desirable due to malignant HYPERTHERMIA -in farms C-section best done under epidural or regional anesthesia

dexmedetomidine

-primarily used for sedating animals (dogs & cats)[30 mcg/kg IM] •recumbency in calves -10 mcg/kg IV •recumbency in the sheep -sedation lasts for one hour

monitoring

-to maintain a proper plane of anesthesia -to prevent excessive insult to CPD & CNS -eye rotates ventrally ♦palpebral reflexes, etc. -little value

Comparing the sensitivity of cattle, horses, and swine to xylazine, which of the following is true?

Cattle are more sensitive than horses, which are more sensitive than swine.

preanesthetic preparation additional(Camelids)

IV catheterization placement -jugular vein •12-14 g for large ruminants •16-18 g for camelids and small animals ♦camelids ◘3-4 cm dorsal to angle of ventral border of mandible ◘cranial to the ventral process of 5th cervical vertabra ◘auricular, or coccygeal

Which of the following statements regarding porcine anesthesia is TRUE

Intravenous sedation is virtually impossible in healthy pigs

Intubation is made easier in pigs by

The use of a stylette

You plan to anesthetize a 1000 kg bull and maintain anesthesia using an inhalant technique. Which of the following statements regarding intubation is correct?

You will have to intubate the bull manually.

Ruminants should be placed in sternal recumbency during recovery to allow them to:

eructate

Which of the following is NOT a symptom of porcine stress syndrome

hypothermia

A hematoma that results from unsuccessful jugular catheterization in a camelid may result in which of the following

pressure on the tracheal wall

When recovering a camelid after general anesthesia, how should it be positioned?

sternal recumbency with the head elevated

diazepam/midazolam

•minor tranquilizer •excellent muscle relaxation •minimal CP depression •in small ruminants -used as premedicants •in large animals - as induction agent (ex. combined with ketamine)[0.02-0.1 mg /kg IV]

butorphanol

-does not provide sedation in a predictable manner -behavioral alteration •restless and bellowing [0.02- 0.05 mg/kg IV] •may provide sedation in cattle that are sick ♦sedation & analgesia is improved with xylazine (or other sedatives) ♦minimal change in HR, BP, CO -can be detected in the milk up to 36 hours

ruminant anesthesia

-equipment -special equipment needed due to size -tilt tables , head gates, transporters, and hoists -anatomy and physiology considerations: •ruminants produce a lot of saliva making them high risk aspiration -prone to regurgitation and bloat •inefficient gas exchanges

Acepromazine

-mild sedation -anti arrhythmic -bull: penile priapism -slow onset -prolonged duration -don't use the coccygeal vein ♦accidental arterial administration ♦subsequent sloughing of the tail distal to the injection site ◘replaced by alpha 2 agonists

endotracheal intubation of swine

-not easy ♦the shape and size of the head ☻laryngoscopy difficult ☻rowson laryngoscope ◘laryngeal spasm -muscle relaxant or local anesthetic spray ◘et tube smaller (ex/ 6 mm ID for a 25 kg pig) ◘malleable metal stylet or plastic urinary catheter

Ruminant anesthesia

-not good for general anesthesia -regurgitation and inhalation of ingested -surgical procedures are carried out by local anesthesia(±sedation) -some procedures are better performed under GA -consideration must be made for drug

nasal tubes placed in a llama

-placed bilaterally in a llama that developed dyspnea from the upper airway obstruction following dental surgery

detomidine

-similar dose to horse's :2.5-10 mcg/kg/iv -duration lasts 30-60 min -40 mcg/kg IV will produce profound sedation and recumbency -side effects: very similar to xylazine -less ecobolic than xylazine in cattle

appropriate positioning of a heifer recovering from anesthesia

-sternal recumbency -maintained in the position to allow eructation(oral ejection of gas air from stomach) -head positioned so pharynx is higher than the mouth, which allows drainage of saliva and regurgitus without aspirating

inhalation anesthesia

•isoflurane, sevoflurane -economic implications ♦problems in greater magnitude than in small animals -hypotension, hypoventilation, and reduction of CO ♦more dramatic consequence if anesthetic plane is not well controlled

camelid positioned for recovery from general anesthesia

•positioned in sternal recumbency •anesthetist, or assistant holds head and neck upright in a normal, neutral position until patient is extubated and able to hold its own neck up

recovery

•sternal recumbency until able to stand ◘et tube must remain in place as cuff inflated ☼tolazoline titrated to effect IV -close observation until on its feet ♣to avoid returning to sleep and danger of aspiration

ET intubation

•the laryngeal spasm not uncommon •topical desensitization of the larynx •nasotracheal intubation alternative to orotracheal intubation •correct placement confirmed by feeling air or reading of CO2

perioperative pain management

○assessment difficult because of their stoic nature -behavioral changes -changes of BT, RR, HR,BP ○routine use of analgesics is recommended -opioids, a2 agonists, local anesthetics, NSAIDs

sensitivity to xylazine

○brahmans/ herefords/ holstein ♣other side effects •hyperglycemia •diuresis •sweating •GIT motility depression •platelet aggregation •uterine contractions in cows ♦reversal by Tolazoline(or yohimbine or atipamezole)

guaifenesin

○centrally acting muscle relaxant -minimal cardiopulmonary depression -little analgesia ♦with a thiobarbiturate or ketamine , induction quality is improved ♠Triple Drip -guaifenesin/ketamine/xylazine (GKX) -one liter 5 % guaifenesin ◘50 mg/ml, final concentration •/100 mg of xylazine ○0.1 mg/ml , final concentration ◘1 gram of ketamine -1 mg/ml--final concentration

anticholinergics

○decrease volume of saliva while making it more viscous ♣more difficult to clear aspirated saliva ◘ruminants have atropinase ↓ GIT motility ◘abdominal discomfort or colic ♦not routinely given in the event of bradycardia ♦camelids more prone to vagala arrhythmias during intubation , and use of anticholinergic is recommended

guaifenesin contd

○loading dose 0.5-2 ml /kg IV drip "to effect" for intubation ♠continue on a slow drip until the isoflurane has fully taken effect(usually 5-10 min) ○following xylazine - ketamine induction ♦guaifenesin - ketamine combo - no need to add xylazine - half life of xylazine is longer than ketamine in cattle ♦intermittently or CRI -0.5 -2 ml./kg/hr

Porcine Malignant Hyperthermia (Porcine Stress Syndrome)

○muscle rigidity ○respiratory and metabolic acidosis ○severe sustained rise of body temp ○hyperkalemia ☼Poland-China; Pietrain; Landrace; Large White, Hampshire;Duroc breed less susceptible ►dantrolene sodium: preemptively or as Tx ♣if suspected, administer oxygen ◄maybe fatal

total intravenous anesthesia (TIVA)

○triple drip(GKX) -minimal CP depression ♦arterial hypoxemia and prolonged recovery ☻not beyond 45 min in an adult cattle ♦propofol -non accumulative -expensive ♦tight anesthetic depth control is harder