Exam #4 Flashcards
How long should food be withheld prior to surgery in the equine patient?
4-8 hours
What are seven things that should be done to prepare the equine patient for anesthesia?
- clean feet
- pull or pad all shoes
- groom/wipe horse
- physical exam/weigh
- clip surgical site
- place jugular catheter
- rinse mouth before induction
What is the equine patient prone to developing under anesthesia?
respiratory acidosis
What is proper positioning and padding important to prevent in the equine patient?
- cardiopulmonary compromise
- neuropathies
- myopathies
Why is assisted or controlled ventilation best for prolonged procedures in the equine patient?
to maintain normal arterial CO2 levels
What is the appropriate dosage range of Xylazine in the equine patient when used as a preanesthetic medication?
IV - 0.2-0.5 mg/lb
IM - 0.5-1mg/lb
What is the onset of Xylazine dosed intravenously in the equine patient?
2-3 minutes as noted by dropping head, prolapse of penis
What is the duration of Xylazine dosed intravenously in the equine patient?
30 minutes
What is the onset of Xylazine dosed intramuscular in the equine patient?
10-15 minutes
What is the duration of Xyalzine dosed intramuscular in the equine patient?
60 minutes
What are two potential complications of Xylazine in the equine patient?
sinus bradycardia; first and second degree heart block
What is the appropriate dosage of Detomidine in the equine patient?
5-10 mcg/lb IV, 10-20 mcg/lb IM
What is the onset and duration of Detomidine in the equine patient?
similar to xylazine but with longer duration of action
What is the appropriate dosage of acepromazine in the equine patient?
0.5 mg/kg given IV or IM
What is the onset of acepromazine in the equine patient?
5-20 minutes
What is the duration of action of acepromazine in the equine patient?
1.5-2 hours
How long may the hypotensive effect of acepromazine last in the equine patient?
up to 12 hours
What size range of endotracheal tubes are appropriate for the equine patient?
30, 26, 20 or 15 mm ID
What supplies should be on hand for placement of an ET tube in the equine patient?
endotracheal tubes, lubrication jelly, 25 CC and/or 60 CC syringe, cotton mouth gag or speculum
What size range of IV catheters are appropriate for the equine patient?
10, 12, or 14 gauge
What supplies should be on hand for placement of an IV catheter in the equine patient?
IV catheter, tubing, flush, fluids, drugs, local anesthetic, cipppers, prep solutions
What is an appropriate O2 flow rate for the equine patient?
1L/250 lb; minimum 3L/1000 lb
What is an appropriate dosage range of ketamine for induction of the equine patient?
0.7-1 mg/lb IV; usual dose is 1 mg/lb
What is the purpose of administering guaifenesin (GG) to the equine patient?
skeletal muscle relaxant
What are toxic signs of guaifenesin in the equine patient?
apneustic breathing, muscle rigidity, hypotension
When is diazepam administered to the equine patient during induction?
before thopental or with ketamine
What are some potential side effects of thiopental sodium in the equine patient?
cardiovascular depression, transient apnea
What is an appropriate dose of Telazol for inducing the equine patient?
0.25-0.5 mg/lb
What differences are there in telazol and ketamine when used to induce the equine patient?
telazol causes greater muscle relaxation of longer duration and causes greater respiratory depression
What is used to induce foals?
isoflurane or sevoflurane
How is ET intubation performed in the horse?
blindly
How is the size of the rebreathing bag determined in the horse?
5x tidal volume
How is anesthesia maintained in the equine patient?
total iv anesthesia or inhalation anesthesia
When should sedatives be administered to adult horses during anesthetic recovery?
Excessive nystagmus; oculogyria
Excessive muscle tremors
Disorientation and loss of equilibrium
What are common anesthetic problems in the horse?
hypotension, hypoventilation, hypoxemia, bradycardia, difficulty maintaining anesthetic depth, metabolic acidosis, under/over hydration, nasal edema/upper airway obstruction, poor or prolonged recovery, neuropathy/myopathy
Why should rumen size and pressure be decreased prior to anesthesia?
to decrease risk of regurgitation
How should rumen size and pressure be decreased prior to surgery?
withhold food, place endotracheal and rumen tubes where appropriate
What preanesthetic evaluation should be performed in the ruminant?
same evaluation as in horses
What is the purpose of administering preanesthetics?
to calm or sedate or to decrease amount of more potent drugs needed
What consideration should be made for preanesthetics being administered to ruminents?
tranquilizers not approved for use in food animals can cause problematic residues in meat and milk products
What is an appropriate dose of Xylazine in the cow?
1/10th the IV dose used in horses - 0.01-0.05 mg/lb
What are the side effects of Xylazine in the ruminent?
cardiovascular and respiratory depression, rumen atony with bloat, premature delivery in late pregnancy
What Xylazine antagonists may be used in the ruminent?
atipamazole, yohimbine, or tolazine
What nonspecific respiratory stimulant may be used?
doxapram
What is an appropriate dosage of detomidine/medetomidine in the ruminant?
5-10 mcg/lb IM (similar to other species)
Why is acepromazine not frequently used in the ruminant?
prolonged elimination
What are some side effects of ketamine and telazol in the ruminant?
respiratory depression, hypotension
What is the advantage of using ketamine or telazol in the ruminant?
they are compatable with inhalation anesthetics
Why are anticholenergics not frequently used in ruminants?
they increase the viscosity of saliva and the incidence of bloat
How is saliva flow best controlled in the anesthetized ruminant?
pointing animal’s head downward and placing cuffed ET tube
When may atropine be used in the ruminant?
if necessary to prevent bradycardia with manipulation of viscera
What drugs may be used for anesthetic induction in the ruminant?
ketamine, telazol, or any one of several illegally compounded drug cocktails, mask induction if under 150 lbs
How may an ET tube be placed in a ruminant?
Dental speculum or mouth gag
Method 1: Insert arm use fingers to reflect epiglottis forward and guide ET into larynx
Method 2: Extend animal’s head and neck gently advance tube into trachea during inspiration
Why is it important to intubate quickly?
to avoid regurgitation and aspiration
What may be performed if necessary to intubate a ruminant?
tracheostomy
How may anesthesia be maintained in the ruminant?
“triple drip”; inhalation anesthetics
What should be performed it the procedure lasts longer then an hour?
the patient should be ventilated
What reflex should be present in the ruminant throughout anesthesia?
corneal reflex
What reflex should be depressed by gan anesthesia in the ruminant?
palpebral reflex
How are the eyeballs positioned in the light surgical plane in the ruminant?
rotated medioventrally
How are the iris and pupil positioned when the patient is awake or in the deep surgical plane?
centered
What is a sign of anesthetic overdose with gas anesthesia in the ruminant?
dilated pupils
How should the ruminant be positioned during the recovery period to avoid regurgitation?
on their right side or in sternal recumbency once the ET tube has been pulled
What may be done to relieve rumen bloat if necessary?
pass a stomach tube
Should the cuff be inflated or deflated while it is being pulled?
inflated
What are common anesthetic problems in the ruminant?
regurgitation, bloat, inadequate oxygenation, injury, respiratory depression/apnea, pulmonary aspiration
What are four unique anesthetic challenges presented by the swine patient?
venous access difficult, endotracheal intubation difficult, respiratory depression common, elevations of body temperature common
Why are elevations of body temperature common in the swine patient?
low body surface area to body mass ratio, absence of sweat glands, malignant hyperthermia in genetically predisposed pigs
When is lumbosacral epidural or spinal anesthesia used in the swine patient?
c-sections
When is intratesticular injection used in the swine patient?
castrations
What are some drugs that may be used to induce anesthesia in the swine patient?
various combinations of injectible drugs (be cautious of legality of compounding drugs), inhalation anesthesia
What are five signs of malignant hyperthermia?
extreme muscle rigidity, increased temperature, tachycardia, tachypnea, metabolic acidosis
What is the treatment for malignant hyperthermia in the swine patient?
dantrolene, supportive therapy including fluids, steroids, oxygen, body cooling
How should the swine patient be recovered from anesthesia?
place in well ventilated, cool and quiet environment, administer oxygen and assist ventilation as necessary, assess vital signs periodically
How should the swine patient be positioned during anesthetic recovery?
sternal recumbency
What are some common anesthetic problems seen in the swine patient?
respiratory depression, malignant hyperthermia
What may be performed in the case of respiratory emergencies in the swine patient?
tracheotomy
What strains of swine are genetically predisposed to malignant hyperthermia?
Landrace, Poland China
What should be discussed with the client before performing an anesthetic procedure on an exotic animal?
realistic expectations, prognosis, risks, the afterare provider, and costs
What body temperature abnormality are small animals predisposed to?
hypothermia
What is a special consideration of body temperature maintenance in ectotherms?
they do not generate their own heat and require external heat sources
What body temperature abnormality are well insulated small animals prone to?
hyperthermia
What body temperature abnormality are ungulates prone to?
malignant hyperthermia
What are two tools that can be used to measure body temperature in the exotic animal patient?
esophageal thermometer, rectal/cloacal thermometer
What routes may fluids be administered in exotic animal patients?
intravenous, intraosseous, intraperitoneal, colonic
What is a complication of administering fluids into pneumatic bones in birds?
iatrogenic drowning
What are some examples of pneumatic bones in birds?
humerus in all, femur in many
What patients should not be given fluids via the intraperitoneal route?
birds or pregnant animals
What is the standard maintenance rate of fluid for the exotic animal patient?
40-100 ml/kg/24 hours
What is the standard intraoperative rate of fluid administration for the exotic animal patient?
10-20 ml/kg/hour
What is the standard shock rate of fluid administration for the exotic animal patient?
30-80 ml/kg in 20 minutes
What rate of fluid administration can use an inline or burette fluid chamber control?
10-50 ml/hour
Why should EDTA be avoided when giving blood transfusions to small patients?
it may cause hypocalcemia
What is the anticoagulant of choice for birds?
heparin
In what species are preanesthetics rarely indicated?
birds, repties, amphibians, fish, mustelids, felids
What preanesthetics are most commonly used in rabbits and lagomorphs?
atropine - uesful to decrease airway secretions; acepromazine and diazepam also useful
Why is acepromazine not used in gerbils?
it may potentiate seizures
What preanesthetic is used in camelids?
medetomidine
What general rule about pulse rate and character should be followed when monitoring the plane of anesthesia?
a decrease in heart rate to
What breathing patterns indicate you should lighten anesthesia?
apneustic or erratic patterns
What breathing pattern is normal in ectotherms at surgical planes of anesthesia?
apnea - administer PPV 4-6x / minute
What modifications should be made to ECG lead placement in the exotic animal patient?
attach clips to steel sutures, metal hubbed needles, or alcohol soaked pads placed at usual lead sites, one clip is placed cranial and one caudal to the heart in legless animals, wings are used for forelimb sites in birds
What modifications should be made to pulse oximeter placement in the exotic animal patient?
tongue, esophageal oral or nasal mucosa, cloaca, vulva, nonpigmented skin such as ear wingweb flank etc
How is the surgical plane of anesthesia determined in the avian (
slow withdrawal response to toe/tail/cloacal pinches, slow third eyelid response (lighten anesthesia when lost)
What anesthesia is preferred in avian patients
inhalation - iso or sevo
Which avian patients should be intubated?
all patients >100g
Why is endtracheal intubation easy to perform in the avian patient?
the glottis is easy to see
Why are ET cuffs not recommened in the avian patient?
the tracheal rings are complete
What can you do if the trachea is occluded in the avian patient?
cannulate caudal thoracic air sacs and suture tube in place, using it as you would an ET tube
How is tidal volume calculated in birds?
15 ml/kg
How should PPV be performed in birds?
2x/minute in self ventilating birds, 10-15x/minute in apneic birds
What should you do if the avian patient becomes apneic during anesthesia?
anesthesia should be lightened immediately or cardiac arrest will follow within 2-5 minutes
How should the avian patient be recovered from anesthesia?
hold in a towel until able to walk, recover rapidly (
What should be done in the event of apnea in the avian patient?
PPV - if no ET tube lift and compress sternum, administer 100% oxygen, doxapram
What should be done in the event of cardiac arrest in the avian patient?
epinephrine, lift and compress sternum, perform laparotomy and internal cardiac massage
What are some special concerns when handling large ratities?
they can disembowel a person - never approach from the front - use large sheets of wood as shields to herd into a corner or chute from the sides/rear
What are some special concerns when handling long billed birds?
always wear eye protection - hoods may help calm/restrain
What are some potential complications of avian anesthesia in patients greater then 30 lbs?
capture myopathy, hyperthermia, leg fractures
When are injectible anesthetics used in avian patients larger then 30 lbs?
short procedures or as induction for gas anesthesia
What drugs may be used to induce the avian patient larger then 30 lbs?
xylazine, telazol, diazepam/ketamine
What form of anesthesia should never be used in the reptile patient?
hypothermia
How do you determine surgical plane of anesthesia in the reptile patient?
toe/tail/vent pinches do not elicit withdrawal - most retain third eyelid reflex
How should larger reptile patients be induced?
mask/chamber induce or use propofol
What rate of fluid administration requires an infusion pump for accuracy?
What heart rate indicates the need to lighten anesthesia?
When should the reptile patient be intubated?
all reptiles attaining surgical levels of anesthesia
How is anesthesia maintained in the reptile patient?
iso/sevo inhalation - ventilate 3-6x per minute
What is the recovery time for isoflurane anesthesia in the reptile patient?
What is the recovery time period for injection anesthetics in the reptile patient?
hours to days
What may speed anesthetic recovery for the reptile patient?
heat and fluids
How is respiratory arrest during anesthesia responded to in the reptile patient?
administer PPV, doxipram
What technique may be used to facilitate respiration in a turtle?
extend/retract the front legs while placing ET tube
How is cardiac arrest during anesthesia responded to in the reptile patient?
100% oxygen, chest compression if no shell, laparotomy - manually compress the heart, epinephrine
What consideration should be made when anesthetizing the amphibian patient?
significant respiration occurs across moist skin - therefore do not allow to dry out and handle with latex gloves or wet hands
What are the stages of anesthesia in the amphibian patient?
similar to mammals, but corneal reflex is lost before the withdrawal reflex
How is tricaine methane sulfonate (MS222/Finquel) administered to the amphibian patient?
IM, SQ, or an immersion bath with an untreated tank available for recovery
What consideration should be taken when using isoflurane on the amphibian patient?
it is irritating to amphibian skin
What is ketamine used for in the amphibian patient?
good for diagnostic but not surgery
How do the respirator systems of fish differ from that of other animals?
they are obligate water breathers and require oxygenated water moving over the gills
How can the fish’s respiration be assisted during a surgical procedure?
using frequent immersion or a small recirculating pump and airstone with the pump tube placed in the fish’s mouth
What considerations should be made to maintain the fish’s exterior mucous layer?
use wet latex gloves when handling and the least amount of restraint possible
What anesthetic agent is used for the fish patient?
Finquel in an immersion bath
How is an anesthetic overdose treated in the fish patient?
move to untreated oxygenated water, pump oxygenated water through the mouth, “swim” the fish
How is the surgical plane of anesthetia determined in the rabbit or rodent patient?
withdrawal reflexes are lost
When should anesthesia be lightened in the rabbit or rodent patient?
when there are decreased heart or respiratory rates or abnormal breathing patterns
Why should low induction settings and preanesthetic agents be used in the rabbit or rodent patient?
they breath hold and then take rapid deep breaths with mask/chamber induction
What considerations should be made when intubating the rabbit or rodent patient?
it is difficult, small ET tubes clog easily so have a replacement tube on hand, take care not to create an iatrogenic tracheitis
How often should PPV be performed for the rabbit/rodent patient?
every 2 minutes
What technique may be used to intubate the rabbit or rodent patient?
retrograde intubation technique - a catheter is passed into the trachea through the ventral neck and used as a stylet for the ET tube
What levels of isoflurane are used to induce the rabbit or rodent patient?
2-3%
What levels of sevoflurane are used to induce the rabbit or rodent patient?
3-5%
How is anesthetic depth in the ferret patient monitored?
similar to cats
What size ET tube should be used in the ferret patient?
2-3MM
What is the anesthetic of choice for the ferret patient?
iso or sevoflurane, mask induction
What food/water withholding period is used for the camelid?
same as for adult cattle - food 24-48 hours, water 24 hours
How should camelids be handled to avoid regurgitation?
same as cattle
