FTK 4: Exotic Animal Anesthesia Flashcards
what are the 5 main exotic animal species?
- fish
- amphibians
- reptiles
- birds
- small mammals
exotic animals have an INCREASED risk of complications/death during…
why is this?
PERIANESTHETIC PERIOD when SEDATION/ANESTHESIA administered!
why?
animals USUALLY ALREADY COMPROMISED UPON PRESENTATION, can hide illnesses well and may be highly stressed
defense reactions (7)
when exotic animals are stressed, perform particular reactions…
- escape reflex
- micturition
- defecation
- rolling
- tail autonomy
- bite
- vocalize
6 things you should ask in history.
taking a COMPLETE & THOROUGH history is the….
6 things?
1. vaccination history
2. cage size/construction
3. eating/drinking
4. behavioral changes
5. husbandry
6. exposure to toxins
MOST IMPORTANT THING A PROVIDER CAN DO WHEN ASSESSING EXOTIC ANIMAL
7 routes of drug administration in exotics?
- IM
- Ice (intracoelomic)
- Inhaled
- TO (topical)
- PO
- IV
- IO
exotic BASICS…
premedication? (what it does & how it’s done)
intubation?
monitoring? (5)
recovery?
premedication?
- helps MINIMIZE STRESS associated with INDUCTION
- done via CATHETER placement
indubation
- RECOMMENDED WHENEVER POSSIBLE
monitoring?
1. SpO2
2. BP
3. Body temperature
4. Capnography
5. Doppler
recovery?
- want QUICK & HIGHLY MONITORED To prevent injury/trauma
how are fish anesthetized for SHORT procedures?
what about LONG procedures?
what compounds are used?
how long until we see effects?
using IMMERSION TECHNIQUE with water that is SIMILAR TO ENVIRONMENT, WELL-OXYGENATED
can also use TANK for RECIRCULATION for longer procedures
MOST often use TRICAINE METHANESULFONATE (MS-222) or CLOVE OIL
takes 5-30 minutes for MS-222 to take effect!
do fish need to be PREmedicated?
NO, just put anesthetic solution in water
3 stages of anesthesia for fish?
- sedation
- loss of equilibrium
- anesthesia
monitoring in fish
most common tool/what it measures?
how to determine respiration rate/what to do when RR stops?
recovery time & 2 signs we see?
DOPPLER measure HR & rhythm and is the MOST COMMON TOOL
determine RR via counting MOVEMENT of OPERCULUM over the gills
If respirations stop, IMMEDIATELY reduce anesthetic in water until respirations RETURN
recovery?
TIME = usually takes 5-10 minutes from after fish is placed in clean, non-anesthetic water
- INCREASE in RR
- COORDINATED fin movements
amphibian anesthesia
differences in larval vs. adult stage anesthetizing?
how to handle/skin?
4 pre-anesthetic considerations (temp, time for induction/recovery, fasting, hypoxia)
larval vs. adult?
LARVAL = AQUATIC/GILLS, so can use IMMERSION TECHNIQUE
ADULT = TERRESTRIAL, so can use IMMERSION TECHNIQUE so long as AIRWAY IS PROTECTED
how to handle/skin?
- must handle with MOISTENED GLOVES
- can administer O2 and DRUGS via SKIN
4 pre-anesthetic considerations…
1. PZOT = 15-23 C
2. has SLOWER INDUCTION & RECOVERY because cardiovascular system has ONE ventricle and TWO atria
3. FASTING is recommended to decrease complications secondary to post-anesthetic ileus
4. RESISTANT TO HYPOXIA caused by APNEA because many respiratory mechanisms
intubation in amphibians
what tool should be used to intubate?
3 reasons why it’s difficult
use NON-CUFFED TUBE ALWAYS
difficult because…
1. GLOTTIS at the BASE OF TONGUE
2. SHORT TRACHEA
3. Paired, FRAGILE saclike lungs
how do we choose an anesthetic technique in amphibians? (4)
- stability of patient
- life stage of patient
- level of anesthesia needed
- species-specific drug sensitivity
main method of induction in amphibians?
what other induction agent can we use & by what 4 routes?
MAIN METHOD = IMMERSION with BUFFERED TRICAINE
1. in ADULTS, make sure that NOSTRILS are kept above water during induction
2. once level of depth achieved, REMOVE from induction solution
3. if LIGHT, APPLY SOLUTION TO SKIN
can also use HALOGENATED anesthetics (iso, sevo) via…
1. TO
2. Injection
3. Immersion
4. Inhalation
MONITORING in amphibians
what 2 tools are used? when should we worry about HR? what tool ISN’T used and why?
3 stages to DEPTH of anesthesia
what 2 tools?
1. **DOPPLER is most common! –> when HR drops by 20% or more, then REDUCE or REMOVE ANESTHETIC SOLUTION CONCENTRATION
2. SpO2
what tool ISN’T used?
1. EKG = myocardium has ACTIVITY AFTER DEATH so NOT REFLECTIVE OF CO
3 stages to DEPTH of anesthesia?
1. INDUCTION = excitement
2. DEEPENING of anesthetic plane…
- respiratory movements DECREASE
- reflexes DECREASE & eventually LOST
3. SURGICAL plane
- marked respiratory depression
- loss of GULAR & PULMONARY VENTILATION
amphibian RECOVERY (2)
why can it be prolonged?
what returns?
- can be PROLONGED due to HEART STRUCTURE
- usually GULAR and WITHDRAWAL RESPIRATIONS return first, then RIGHTING REFLEX
what 3 species of reptiles have a cardiopulmonary system that’s similar to amphibians?
what is this system? (+2 things it leads to)
3 species?
1. chelonians
2. lizards
3. snakes
system?
oxygenated & de-oxygenated blood can MIX/SHUNT to BYPASS THE LUNGS DURING APNEIC PERIODS –> REDUCED INHALANT UPTAKE/EXHALATION –> SLOWER INDUCTION/RECOVERY
4 different pre-anesthetic considerations for REPTILES
temp, eating, organs, anatomy
- POIKILOTHERMIC, need to be maintained at PZOT = 20-25 C to maintain METABOLISM, ABSORPTION & EXCRETION
- FAST for ONE FEEDING CYCLE because they can REGURGITATE
- RENAL PORTAL SYSTEM = blood can either go THROUGH kidneys or BYPASS to get to CAUDAL VENA CAVA AND LIVER
- NO DIAPHRAGM = relies on ABDOMINAL muscles to breathe
lizard/chelonian vs. snake lungs?
lizard/chelonian = PAIRED, SACLIKE Lungs
snakes = vestigial LEFT LUNG and FUNCTIONAL RIGHT LUNG that ends in terminal air sac
INTUBATION in reptiles
who is it recommended for?
what should you use? who is this especially important for/why?
certain anatomic structure that can make this hard/locations?
recommended for ALL REPTILES
should use an UNCUFFED ET TUBE, especially for CHELONIANS because they have COMPLETE TRACHEAL RINGS
GLOTTIS location varies!
- snakes = ROSTRAL
- lizards/chelonians = BASE OF TONGUE, makes it harder to intubate
5 options for INJECTABLE anesthetic drugs in reptiles?
3 options for INHALANT ADMINISTRATION routes for anesthetic drugs?
injectables?
1. opioids
2. alpha-2 agonists
3. benzodiazepines
4. propofol
5. ketamine
inhalant routes?
1. mask
2. ET tube
3. chamber induction
MONITORING in reptiles
how to we gauge depth of anesthesia?
likelihood of spontaneous arousal/why? what 2 things can we do to MINIMIZE this?
ventilation rate?
5 pieces of equipment?
depth of anesthesia based on PAIN REFLEX
SPONTANEOUS AROUSAL LIKELY because blood can be SHUNTED FROM LUNGS, but these 2 things can minimize it…
1. mechanical ventilation
2. supplementation of anesthetic drugs
1-2 breaths/minute once at anesthetic plane
5 pieces of equipment?
1. DOPPLER (most EFFECTIVE)
2. ECG
3. Respiratory monitors
4. Temperature probes
5. ANTIVENIN if animal is venonmous
VENTILATION in birds is done by what 4 structures? what 1 structure does GAS EXCHANGE?
VENTILATION
1. thoracic skeleton
2. respiratory muscles
3. air sacs
4. conducting airways
GAS EXCHANGE
1. parabronchial lung
5 pre-anesthetic considerations in birds?
anatomy, resp frequency, diaphragm, anatomy 2 (u know this), lung volume
- LARYNX
- NO GLOTTIS
- larynx is at BASE OF TONGUE that PROTRUDES INTO PHARYNX, making INTUBATION EASY
- intubation DIFFICULT when CURVED BEAK/THICKENED TONGUE - respiratory FREQUENCY is only 1/3 of MAMMALS
- NO DIAPHRAGM
- respiration is ACTIVE, be careful with POSITIONING - COMPLETE TRACHEAL RINGS
- has 4.5x more tracheal dead space than mammals - has GREATER TIDAL VOLUME but LESS TOTAL VOLUME in lungs
- LOW functional residual capacity = prone to HYPOXEMIA during APNEA
bird anatomy
heart structure?
renal portal system?
dive response/who’s it more common in/how to minimize/danger?
fasting in large and small birds?
heart structure?
- 4-chambered heart with PURKINJE TYPE 2B FIBERS
- fibers penetrate from EPICARDIUM –> MYOCARDIUM, so expect LONG, DEEP QRS COMPLEXES w/ FAST HR
renal portal system?
- PRESENT! blood can bypass or go through kidneys
dive response?
- TRIGEMINAL NERVE stimulation to STRESS that causes BRADYCARDIA & APNEA
- common in WATERFOWL
- minimized through PREMEDICATION
- can be FATAL
fasting?
- CONTROVERSIAL depending on metabolic rate
- LARGE BIRDS = overnight
- SMALL BIRDS = 4-6 hours
3 things to do if bird is NOT fasted for INDUCTION?
- hold bird UPRIGHT during induction
- keep finger UNDER MANDIBLE to BLOCK ESOPHAGUS
- can EMPTY CROP UNDER GA
INTUBATION in birds
who’s it recommended for?
what tool should we use? what if this isn’t possible?
danger of improper administration?
recommended for ALL BIRDS
normally use UNCUFFED ET TUBE (Cole tube), but can also do AIR SAC CANNULATION
TUBE SHOULD NEVER FIT TIGHTLY because then we can RUPTURE TRACHEAL MUCOSAL RING, leading to GOING OFF OF FOOD ~1 WEEK POST-OP
INJECTION sites in birds
general rule of thumb?
SQ? (3)
IM? (2)
IV? (3)
GENERALLY, inject into CRANIAL HALF of bird
SQ?
1. area between wings on back
2. wing web
3. inguinal skin fold
IM?
1. pectoral
2. thigh
IV?
1. ulnaris
2. dorsal metatarsal
3. jugular (R>L)
INJECTABLE (5) and INHALANT (2) anesthetic drugs in birds? something special about MAC?
injectables?
1. benzodiazepines
2. opioids
3. alfaxalone
4. propofol
5. ketamine
inhalants?
1. isoflurane
2. sevoflurane
MAC = Minimum Anesthetic Concentration because NO ALVEOLI
MONITORING in birds
rate of induction/recovery and why?
which should be ventilated?
6 parameters measured?
RAPID induction and recovery because EFFICIENT GAS EXCHANGE SYSTEM
ALL birds should be ventilated
parameters?
1. RR
2. lung volume
3. capnography
4. SpO2 –> mostly for TRENDS over time, will UNDERESTIMATE at HIGH O2 SATURATION and OVERESTIMATE at LOW O2 SATURATION
5. Body temperature
6. BP
–> can do DIRECT for > 4 kg
–> DOPPLER otherwise
RECOVERY in birds
restraint?
recovery risks?
extubation?
make sure to NOT BURRITO; can harm BREATHING CAPABILITIES while MAINTAINING BODY TEMP
watch for REGURGITATION
extubate once SPONTANEOUS BREATHING and return of JAW TONE/TONGUE MOVEMENTS
3 pre-anesthetic considerations for SMALL MAMMALS
- SMALL SIZE, so hard to CATHETERIZE, INJECT, or INTUBATE
- HIGH METABOLISM
- FASTING NOT NECESSARY IN RODENTS/RABBITS bc they DO NOT VOMIT
- Ferrets = fast for 1-3 hours because HIGH TRANSIT TIME
- Rodents/Ferrets prone to HYPOGLYCEMIA, might need DEXTROSE - PRE-EXISTING RESPIRATORY DISEASE
- should ALWAYS GIVE OXYGEN SUPPLEMENTATION
INTUBATION in small mammals
what should we ensure BEFORE intubation?
2 reasons it’s challenging?
4 techniques/materials
make sure animal is AT AN ADEQUATE ANESTHETIC DEPTH before intubation
2 reasons it’s challenging?
1. oropharyngeal secretions can OBSTRUCT ET tubes
2. hard to visualize LARYNX because of THICK TONGUE & LARGE INCISORS
ANESTHETIC DRUG ROUTES (5, 2 most common) & TYPES in small mammals
ROUTES?
1. IV
2. SQ
3. IP (intraperineal)
4. Inhaled
5. IM
INJECTABLE & INHALANT ARE MOST COMMON
Types?
INJECTABLE
1. Alpha-2 agonists
2. Opioids
3. Ketamine
4. Benzodiazepines
5. Propofol
INHALANT
1. Isoflurane
2. Sevoflurane
3. Desflurane
MONITORING in small mammals
how do we check anesthetic depth?
what 3 parameters do we always do?
what 4 other parameters can we use?
check anesthetic depth via PHYSIOLOGIC REFLEXES
3 parameters we ALWAYS do…
1. HR
2. RR
3. Body temp
other parameters?
1. SpO2
2. Capnography
3. ECG
4. NIBP, IBP
RECOVERY in small mammals
what 2 things should be CONSISTENTLY monitored?
what 2 measures for monitoring status?
what can ENHANCE recovery?
2 things?
1. BODY TEMPERATURE
2. ABLE TO PROTECT THEIR OWN AIRWAY
2 measures?
1. PAIN scores
2. GRIMACE scales
ENHANCE recovery = ANALGESIA
