Exam 4: Lecture 27 - Exotic Animal Anesthesia Flashcards
T/F: rabbits have an increase anesthesic risk compared to dogs and cats
true
minimize fasting of rabbits prior to sx no more than ________
1 hour
what is the best way to restrain a rabbit
support the rump and tuck head under your arm or make a “bunny burrito”
do rabbits have a high or low metabolic rate and rapid elimination of drugs
high metabolic rate and metabolism
T/F: we should always premed rabbits
truuuuuuuuuuuuuueee
what drug should we NOT use alone for rabbit premedications
ketamine
what drugs can we use for pre-med for rabbits
ketamine with a benoz, acepromazine, or alpha-2 agonist
what inhalants are used for maintenance of rabbit anesthesia
isoflurane or sevoflurane
what 2 things should we monitor very closely with rabbit anesthesia
hypothermia and hypoglycemia
T/F: we MUST pre-oxygenate rabbits prior to anesthesia
true. it is VERY important to
what size ET tube should we use for rabbits
2-4mm murphy
how do we intubate rabbits
keep head and neck extended to prevent obstruction, spray lidocaine on larynx first
what is different about bird anatomy and physiology that can make anesthesia more complicated
- the respiratory system has a separate ventilator and gas exchange compartments
- complete tracheal rings which can collapse during restraint
- no diaphragm so inspiration and expiration is active
- pneumatized bones
T/F: apnea in birds breathing room air must be treated immediately
big true!
what is the varying HR for avian species
150-1000bpm
when catecholamines are released during stress and pain, what can happen
arrhythmias
do birds have a renal portal system
yes they do but the clinical significance is debated
T/F: hypoglycemia does not need to be corrected before anesthesia
false, it does
how long can we fast medium-sized psittacines
2-4 hours
how long should we fast birds less than 200g
WE SHOULD NOT FAST
what is the best way to restrain a bird
by using a towel
what is a good way to prevent hypothermia in birds
warm fluids at 10ml/kg/hr
where can we place an IVC in birds
ulnar, medial metatarsal, jugular veins
where are the IO sites in birds
distal ulna or proximal tibiotarsus
what is the most effective way to minimize hypothermia in birds
forced air warmers
how can we prevent apnea and bradycardia during mask inductions in waterfowls
premed with benzo
how long should we pre-oxygenate birds before induction
5 mins before induction
T/F: we should avoid midazolam in macaws and cockatoos
true!!
what drugs may have adverse effects in birds and we should use great caution
alpha-2 agonists
what should we combine ketamine with for birds
benzodiazepines
T/F: propofol has a narrow margin of safety in pigeons and chickens
true
can we use iso or sevo in birds
yes but it is more likely to cause apnea compared to mammals
T/F: lidocaine toxicity occurs at higher dosages than in dogs
false, it is toxic at LOWER doses
T/F: NSAIDs and opioids are commonly used in birds
true
what should we do to monitor birds during anesthesia
- monitor trends of vital signs
- palpate pulse.doppler placement
- place ECG leads close to body, se needle or suture to attach leads
- indirect BP - cuff around thigh or distal humerus
- ETCO2 is useful
- absence of palpebral and corneal reflex = excessive depth
- extubate when jaw tone returns
T/F: in birds, SpO2 is useful for monitoring anesthesia
false, ETCO2 is useful. SpO2 is not validated
what is uncommon and common in white-tailed and mule deer
ruminal tympany is uncommon but hypoxemia is common
what can occur in north american elk
ruminant tympany and hyperthermia can occur
what are bison prone to
bloat, hypoxemia, regurg
T/F: caribou are difficult to immobilize so higher drug doses are required
true!
what is special about pronghorn antelope
extremely difficult to immobilize so there are high drug requirements and hyperthermia is common
what is exertional myopathy (capture myopathy)
life threatening syndrome caused by a combination of sympathetic exhaustion from sustained stress and intense muscular exertion
T/F: exertional myopathy is easy to treat so prevention is not that important
false, it is difficult to treat to prevention is KEY
how long should captured wild animals not be handled or stressed
at least 6 weeks
what should we do is the mortality rate of exertional myopathy is >2% during chemical immobilization
we should re-eval the anesthetic protocol
what environmental factors can increase incidence of extertional myopathy
temp, humidity, rain, difficult terrain
what is acute death syndrome (capture shock syndrome)
weak and depressed, remains recumbent after reversal and shock/death within 3-4 hrs
what is delayed peracute death syndrome
appears to be in good condition after capture but if stressed again then ventricular fibrillation and cardiac arrest
what is ataxic myoglobinuric syndrome
ataxia, brownish urine, usually die within hours or days after capture due to kidney failure following myoglobin-mediated tubular destruction
what is ruptures muscle syndrome
with 1-2 days post capture animal is unable to support weight on hind limbs. hocks are usually hyperflexed, increased CK, LDH, SGOT and animal usually dies within 3-4 weeks
what are the ultra-potent opioid drugs
carfentenil, etorphine, thiapentanil, diprenorphine (M50-50)
what is carfentenil
8000x more potent that morphine, causes muscle rigidity when used alone, usually used with another sedative, long duration of action
what is etorphine
2.5x less potent than carfentenil. Can be used alone or with a sedative. very effective in ungulates, rhinos, and elephants…can last up to 7-8 hrs
what is thiapentanil
6000x more potent than morphine, more rapid onset and briefer duration of action than carfentenil
what is diprenorphine (M50-50)
antagonist used to reverse etorphine but has agonist properties as well…..so over dose may cause continued immobilization
what is important about zebras and anesthesia
respiratory depression and hyperthermia are common…. skin is very thin so lightweight darts with low impact energy should be used to avoid penetration wounds
what drugs should be avoided in zebras and what can we use instread
carfentanil should be avoided due to side effects
a combo of etorphine + detomidine + butorphanol
what is important to remember about giraffes and anesthesia
- increased anesthetic risk…BP must be maintained in normal range to supply blood to the brain!
- head and neck must be controlled at all times
- want a short induction and recovery
- intubation is difficult and they are prone to hypoxemia…also must be fasted for 24 hrs
what is important to remember about black rhinos compared to white rhinos
black rhinos are less sensitive to respiratory depression following etorphine than white rhinos
Rhinos are prone to the same anesthetic risk as ______
horses
what must we consider with rhinos and anesthesia
- very thick skin
- extremely dangerous but their horns can be easily traumatized
- passive and active regurg occurs so NPO 12-48 hrs, no water for 12 hrs
- if body temp >41 degrees celsius then reverse anesthesia
what is the body weight of a savannah elephant
4000-6500kg
T/F: we should consider social and repro behaviors of elephants for our anesthetic plan
true
Elephants have __1__ eyesight but __2__ hearing and smell
- poor eyesight
- excellent hearing and smell
what is the drug of choice and preferred darting sites of elephants
etorphine
hind leg, back, shoulder
how do we avoid respiratory depression and hypoxemia in elephants
they should be intubated and placed in lateral recumbency and avoid obstruction to breathing through the trunk
what causes pink foam syndrome in elephants
may be due to hypertension from opioids or stress from capture
what felid species has the most anesthetic complications
tigers
what drug may cause sudden death and in controversial to use in tigers
telazol
how long should felids be fasted
12-24 hours
T/F: in general smaller felids require higher drug dosages per kg of body weight
true!!
what do most anesthetic protocols for felids contain
ketamine + alpha-2 agonist +/- opioid combo
when should we extubate felids
when ears or eye movement occurs instead of swallowing
what is important to remember about brown bears and weight for anesthesia
in autumn, the body weight increases up to 40% but in winter we should decrease the doses due to hypometabolic state
what should we remember about the polar bear and anesthesia
- substantial body fat deposits throughout the yr
- shoulder and neck are best sites for drug delivery
- hypometabolic state in summer so decreased drug doses
- hypoxemia is common
- position carefully to avoid compartment syndrome
T/F: black bears are easily excitable so higher doses of telazol are needed
false, they are more placid in nature
______ based combinations are unreliable in brown and polar bears
ketamine based
T/F: it is important to use a blindfold for bears
true!
what drug produces the most reliable anesthesia in bears
telazol
what are 2 common complications of anesthesia in bears
hyperthermia and acidosis
what is important about fish and anesthesia
- no lungs but do respire and require O2 so adequate O2 levels in water is critical
- gils are designed to have water flow cranial to caudal so anesthesia should be delivered in same direction
- anesthetic agents can dissolve in water so it is safe and simple for fish
how do we plan an anesthetic case for fish
- obtain base line behavior parameters
- fast for 12-24 hrs
- prepare induction, maintenance, and recover water containers
- prevent drying of skin, fins, and eyes
what are extra considerations for fish and anesthesia
- extrapolating dosages to all species can be harmful
- lower temp can lead to prolonged induction and recovery
- marine species less tolerant of hypoxic conditions than fresh water
- failure to perfuse gills = suffocation
what is the MOST important thing to remember about fish
failure to perfuse gills will lead to suffocation
what is the most common fish anesthetic and what can it be used for other than anestheisa
MS-222
can be used for sedation, surgical anesthesia, or euth
what can we use for koi and trout
clove oil (eugenol) but has a narrow margin of safety
what inhalant can be bubbled into water for fish
vaporized iso but it takes longer
what are 7 important things for reptile anesthesia
- maintain body temp
- squamates and chelonians have an anatomically 3 chambered heart but functions as a 5 chamber
- HR varies inversely with temp and body size
- no true diaphragm
- BG levels are generally lower
- fasting is recommended prior to anesthesia
- recovery can take a long time (up to hours)
what are the 2 most important concepts about ventilation in reptiles
- reptile may convert to anaerobic metabolism if they are not spontaneous breathing or are being ventilated by IPPV
- low oxygen levels stimulate breathing
what is important to know about reptiles specifically squamates
- lizard heart is between forelimbs and snakes are 20-25% of body length from head
- left lung is vestigial in snakes and vascular lung provides SA for gas exchange
- all lizards bite
- IV access is difficult in snakes
what are the 8 important things about chelonians
- dorsal surface of lung is attached to carapace and ventral surface is joined to connective tissue
- shell is included in BW when calculating drug dosages and IM injection is in forelimbs
- capable of delivering a serious bite
- keep patient at POTZ
- air moves through nares so open nose breathing is BAAAAD
- short trachea with completely tracheal rings
- ETCO2 not as accurate due to cardiac sinus
- ventilation assisted
what are the 3 important things about crocodilians
- careful planning to restrain patient is needed since they can roll, bite, whip tail
- heart is located in cranial 1/3 of coelomic cavity
- both hear chambers completely divided so a foramen connects both aortic arches
