anesthesia final review

what does MAC stand for?

minimum alveolar concentration

what is the definition of MAC?

-50% of patient’s respond to surgical stimuli

true or false: anesthesia decreases cardiac contractility in all species

true

what should you always do before your equine patient is induced and intubated?

flush everything

before injecting any local anesthetics, what should you ALWAYS do?

aspirate- you do not want to see blood

pH range

7.35-7.45

pO₂ range

90-600 mmHg (300-400)

SA pCO₂

35-45 mmHg

LA pCO₂

45-55 mmHg

HCO₃ range

18-26 mEq/L

BE range

-5-5

TCO₂ range

24-26 mEq/L

SpO₂ range

>95

what is different about pre-med dosing in draft horses than other horses?

you want to decrease the dose

can birds ventilate easily on their own under anesthesia?

no because they have to use their muscles to breathe. the vasodilation leads to respiratory depression

which of the following is a dissociative induction drug?

1. xylazine

2. propofol

3. isoflurane

4. ketamine

ketamine

which of the following is an induction agent that causes apnea if given too fast?

1. xylazine

2. propofol

3. isoflurane

4. ketamine

propofol

which of the following is an alpha-2 agonist?

1. xylazine

2. propofol

3. isoflurane

4. ketamine

xylazine

which of the following is a sedative premedication?

1. hydromorphone

2. acepromazine

3. glycopyrrolate

4. fentanyl

acepromazine

which of the following is an anticholinergic agent?

1. hydromorphone

2. acepromazine

3. glycopyrrolate

4. butorphanol

glycopyrrolate

which of the following is an inhalant?

1. xylazine

2. propofol

3. isoflurane

4. ketamine

isoflurane

which of the following is an opioid?

1. hydromorphone

2. acepromazine

3. glycopyrrolate

4. isoflurane

hydromorphone

would you dose a mini horse the same as a normal horse?

yes

how long should you fast ruminants?

12-48 hours

why do we fast ruminants for so long?

decrease the chances of regurgitation and prevent bloating

what species has a palatal ostium making it harder to intubate them?

guinea pigs

what species has a lot of SQ fat that delays drug absorption?

hedgehog; go IM instead

What small mammal species will regurgitate during induction?

ferret

What small animal species produces copious amounts of secretions that can cause ET tube obstruction?

chinchilla

What small mammal species would you intubate similar to a cat using lidocaine?

ferret

This small mammal species can have extremely high heart rates.

mice

What small mammal species has cheek pouches that you need to check before intubation?

guinea pig

What species will self mutilate if they are given irritating IM drugs?

mice and rats

Which of the following is an anticholinergic drug used to increase heart rate?

a. Atropine

b. Diazepam

c. Ketamine

d. Xylazine

atropine

Which of the following is an inhalant?

a. Atropine

b. Sevoflurane

c. Diazepam

d. Xylazine

sevoflurane

Which of the following is a benzodiazepine sedative?

a. Atropine

b. Sevoflurane

c. Diazepam

d. Xylazine

diazepam

Which of the following is an alpha-2 agonist used mostly in horses?

a. Atropine

b. Sevoflurane

c. Fentanyl

d. Detomidine

detomidine

Which of the following is an alpha-2 agonist used in many different species?

a. Diazepam

b. Fentanyl

c. Xylazine

d. Atropine

xylazine

Which of the following is a mu agonist opioid?

a. Fentanyl

b. Xylazine

c. Diazepam

d. Atropine

fentanyl

What is the minimum mean BP for a small animal?

60 mmHg

What is the minimum mean BP for a horse?

70 mmHg

What 5 drug classes provide analgesia?

NSAIDS, local anesthetics, opioids, alpha-2 agonists, dissociatives

What block can we use in equine for perineal, rectal or vaginal procedures?

caudal epidural

List some important considerations when performing anesthesia on rabbits.

● Proper restraint is important to make sure they don’t injure their back

● Need to be fasted from grain/pellets to avoid risk of bloat and make ventilation easier ● Need increased doses of atropinewhy

why do we increase the dose of atropine in rabbits?

they produce endogenous atropine esterases which are enzymes that break down atropine

What percentage of body weight is blood volume for large and small animals?

8%

What percentage of body weight is blood volume for exotics/small mammals?

60-80 ml/kg

What percentage of blood volume can a patient safely loose?

20%

What is the most useful tool for monitoring a reptile?

ultrasonic doppler

What are the main issues caused by hypothermia?

● Changes in depth: patient will become deeper the colder they get

● Bradycardia

● Decreased response to drugs due to slower metabolism

Why would you NOT want to give diazepam IM?

It has poor/erratic IM absorption; always want to give IV

Why would you not want bupivacaine to go IV?

It is the most cardiotoxic local anesthetic

When should you extubate a calf?

When they are swallowing/chewing on the tube

When should you extubate a horse?

They are breathing steadily and almost swallowing

When should you extubate a turtle?

When they are spontaneously breathing on their own

When should you extubate a dog?

When they are breathing steadily and swallowing

What should you extubate a bird?

When they are able to support their own head and breathing on their own.

What is the best choice of opioid for large animal/avian/geriatric and pediatric patients?

a. Butorphanol

b. Dexmeditomidine

c. Fentanyl

d. Hydromorphone

butorphanol

What premed drug are ruminants sensitive to?

a. Butorphanol

b. Xylazine

c. Atropine

d. Telazol

xylazine

What drug dries up secretions and is controversial in ruminants because it causes ropey saliva?

a. Butorphanol

b. Xylazine

c. Atropine

d. Telazol

xylazine

Which of the following drugs is a muscle relaxant?

a. Butorphanol

b. hydromorphone

c. Telazol.

d. Guaifenesin

guaifenesin

Which of the following is commonly used for IM injection in swine?

a. Butorphanol

b. Hydromorphone

c. Telazol

d. Guaifenesin

telazol

Patients generally maintain their reflexes with what analgesic induction agent class?

a. Benzodiazepines

b. Dissociatives

c. Alpha-2

d. NSAIDS

dissociatives

This premed drug class will cause mostly muscle relaxation but some unreliable sedation.

a. Benzodiazepines

b. Dissociatives

c. Alpha-2

d. NSAIDS

benzodiazepine

Which premed drugs provides sedation, muscle relaxation and analgesia.

a. Opioids

b. Non-barbiturates

c. alpha-2

d. benzodiazepines

alpha-2

This induction drug class can cause apnea when given but provides no analgesia.

a. Benzodiazepines

b. Non-barbiturates

c. Alpha-2

d. NSAIDS

non-barbiturate

You should not give these analgesic drugs with steroids.

a. NSAIDS

b. Alpha-2

c. Benzodiazepines

d. Opioids

NSAID

These premedication drugs provide analgesia and sedation and they have mu and kappa agonists

a. Alpha-2

b. Benzodiazepines

c. Opioids

d. NSAIDS

opioids

Do you need a laryngoscope to intubate a horse?

No, horses are a blind intubation

Which of the following induction agents provides analgesia?

a. Propofol

b. Etomidate

c. Ketamine

ketamine

What drugs are included in triple drip (GKX)?

Guaifenesin, ketamine, xylazine

What drug is often used in large animal, specifically equine, but needs to be used at lower doses in ruminants?

a. Butorphanol

b. Propofol

c. Ketamine

d. Xylazine

xylazine

What are some ways we can help a recovering equine patient to breath through its nose if it has edema?

● Place a nasotracheal tube

● Neosynephrine (nasal decongestant spray)

What species do you NOT have to withhold water from before anesthesia?

a. Sheep

b. Goat

c. Cow

d. Rabbit

rabbit

What should you always do with an equine patient before intubation to decrease risk of food aspiration?

Wash out mouth/cheeks

What 3 local block techniques would you use to block the flank region of a cow for something like a c-section?

● Inverted L

● Proximal paravertebral block

● Distal paravertebral block

What is the order of the pain pathway when a pain response is elicited?

● Stimulus applied, transduction, transmission, modulation, perception

What are the benefits and disadvantages of a non-rebreathing system?

● Benefits: Gives the anesthetist better control over patient depth and it is less work for the patient to breath with less valves to breathe through.

● Disadvantages: requires a higher oxygen flow = colder air to patient = colder patient, costs more to operate

What are the benefits and disadvantages of a rebreathing system?

● Benefits: costs less to operate, delivers warmer air to patient

● Disadvantages: More valves to breath through = harder work for patient to breath, less control over patient depth because changes take longer

What is the gas co-efficient?

The blood/gas solubility or how much anesthetic is dissolved in the blood. High coefficient means a large amount dissolved in the blood

When moving your patient or changing their position what should you always do?

Disconnect them from the circuit to prevent tracheal tear/trauma

Why do we use pre-anesthetics?

● Lower the dose of induction drugs

● Lower the dose on inhalant needed

● Reduce patient stress/anxiety

● Chemical restraint

● Pre-emptive analgesia

● Counteract side effects caused by other premeds