Anesthesia Intro

Question 1

what is the ASA physical status scale used for?

Answer 1

determining the risk of putting a specific patient under anesthesia

Question 2

ASA I

Answer 2

minimal risk
normal, healthy animal with no underlying disease

Question 3

ASA II

Answer 3

slight risk, minor disease present
slight-mild systemic disturbance, animal able to compensate, neonate, geriatrics, obese animals

Question 4

ASA III

Answer 4

moderate risk, obvious disease present
moderate systemic disease/disturbances, mild CS, anemia, moderate dehydration, fever, low-grade heart murmur/cardiac disease

Question 5

ASA IV

Answer 5

high risk, significantly compromised by disease
animals with preexisting systemic disease/disturbances of severe nature
severe dehydration, shock, uremia, toxemia, high fever, uncompensated heart disease, uncompensated diabetes, pulmonary disease, emaciation

Question 6

ASA V

Answer 6

extreme risk, moribund
surgery performed in desperation on animal with life threatening systemic disease
advanced cases of heart, kidney, liver, or endocrine disease, profound shock, severe trauma, pulmonary embolus, terminal malignancy

Question 7

anesthesia

Answer 7

loss of sensation
common halogenated anesthetics: Isoflurane, Sevoflurane, Desflurane
older anesthetics: Methoxyflurane, Halothane, Enflurane

Question 8

analgesia

Answer 8

absence of pain
opioid type: agonists, partial agonist, agonist antagonist, antagonist
preemptive analgesia is essential

Question 9

sedation

Answer 9

CNS depression and unawareness of surroundings caused by administration of a drug
good for simple procedures

Question 10

tranquilizer

Answer 10

CNS depression and awareness of surroundings caused by drug administration
good for anxious patients

Question 11

neuroleptanalgesia

Answer 11

state of profound sedation and analgesia produced by the administration of an opioid and a tranquilizer
ex: Hydromorphone and acepromazine, Fentanyl and midazolam

Question 12

opioids

Answer 12

derived from opium
synthetic or natural forms
used for analgesia or as an adjunct for induction
may be used as CRI +/- with other drugs
great MAC reducer

Question 13

versatile opioid classes

Answer 13

agonists, partial agonists, agonist-antagonists, antagonists

Question 14

opioid mode of action

Answer 14

opioid receptors found on neurons throughout the body, brain, spine
produce effects of sedation and analgesia

Question 15

what are the 3 major opioid receptors?

Answer 15

mu, kappa, delta
each receptor produces a different effect

Question 16

which classes of opioids bind to which receptors?

Answer 16

full agonists bind to mu and kappa receptors, best analgesics
partial agonists bind partially stimulate mu receptors
mixed agents only bind to kappa receptors
antagonists bind to but don’t stimulate mu and kappa receptors

Question 17

which class of opioids is best for dogs?

Answer 17

agonists produce maximal effects on dogs

Question 18

which class of opioids is best for cats, horses, and ruminants?

Answer 18

partial agonists work best in cats, horses, and ruminants

Question 19

full agonist opioids

Answer 19

morphine, hydromorphine, oxymorphone, fentanyl, meperidine, and methadone
cause histamine release
C-II controlled
IV, IM, SQ, ID, epidural

Question 20

partial mu agonist opioids

Answer 20

they have a ceiling effect = at some point increasing dosages won’t increase analgesia
ex: Buprenorphine (Buprenex)

Question 21

Buprenorphine (Buprenex)

Answer 21

C-III controlled
delayed onset action: 45-60 minutes
duration: 4-6 hours
IV, IM, epidural, TM (cats)
kappa-receptor antagonist and partial mu agonist
AE: respiratory depression, pain on injection site

Question 22

Simadol

Answer 22

long acting Buprenorphine injectable for cats

Question 23

Butorphanol

Answer 23

mixed agonist-antagonist opioid
C-IV controlled
antitussive effects too
partially reverses opioid agonists
less respiratory depression and potential for abuse
has ceiling effect
half life: 20-50 minutes
duration: 2-6 hours

Question 24

opioid antagonists

Answer 24

have a higher affinity for opioid receptor sites than narcotics do so they displace bound molecules and prevent binding of new opioid molecules to their receptors
used to treat the respiratory and CNS depression caused by opioids

Question 25

Naloxone

Answer 25

full mu opioid antagonist
IV, IM, SQ
administration for neonates after C-section: sublingual or injected into umbilical vein
ER drug, reverses opioids
IV and sublingual onset: 1-2 minutes
IM onset: 10-20 minutes
doesn’t revere Buprenorphine

Question 26

Tramadol

Answer 26

atypical opioid
centrally acting
mostly mu receptor activity
SNRI (serotonin and norepinephrine reuptake inhibitors)
C-IV controlled
oral, IV

Question 27

Gabapentin

Answer 27

atypical opioid
oral add-on anticonvulsant
inhibits calcium channels resulting in decreased excitatory neurotransmission
excreted by kidneys
capsules and oral solution

Question 28

NSAIDs

Answer 28

nonsteroidal anti-inflammatory drugs: decrease inflammation by blocking action of the enzyme cyclooxygenase (COX)
steroidal anti-inflammatory drugs: contraindicated for surgery, delays healing
not immunosuppressive
have antipyretic effects (fever reducing)

Question 29

types of cyclooxygenase enzyme (COX)

Answer 29

COX-1 and COX-2
COX-1 performs activities that maintain health
COX-2 is involved in production of prostaglandins that promote inflammation

Question 30

what two drugs shouldn’t be administered concurrently?

Answer 30

NSAIDs and glucocorticoids

Question 31

salicylates

Answer 31

oldest anti-inflammatory agents
aspirin: analgesic, antipyretic, anti-inflammatory, decreases platelet aggregation
non-selective inhibitor so blocks COX-1 and COX-2, not FDA approved

Question 32

propionic acid deriatives

Answer 32

ibufropen (humans), ketoprofen (horses), carprofen (dogs), naproxen (horses)
-fen drugs
ibuprofen not animal approved
analgesic, antipyretic, anti-inflammatory

Question 33

selective COX-2 inhibitors (drug names)

Answer 33

Deracoxib, Firocoxib, Robencoxib

Question 34

Deracoxib

Answer 34

selective COX-2 inhibitor
dogs > 4lbs, pain and inflammation, give after meal, blood chem before use

Question 35

Firocoxib

Answer 35

dogs and horses
treats fever pain and inflammation, chewable tablet for dogs, oral paste for horses
caution with renal, hepatic, or cardiao dysfunction patients

Question 36

Robenacoxib

Answer 36

dogs and cats, > 5.5 lbs and > 4 months old
injectable and tablets
give without food

Question 37

Oxicam

Answer 37

Meloxicam: preferentially inhibits COX-2
approved for: dog (injectable, oral, or transmucosal), cat (injectable, oral, extra-label), large animal (extra-label)
don’t use with liver, cardiac, kidney, or GI patients

Question 38

local anesthetics

Answer 38

lidocaine, bupivicane, mepivacaine, procaine
ophthalmic anesthetics: tetracaine and proparacaine
blockade of sodium channels if deposited in proximity to the neuron
infiltration, topical, intraarticular, nerve plexus, vein, or epidural

Question 39

Lidocaine

Answer 39

injectable, topical, patch
rapid onset
short duration
mix with epinephrine for longer duration

Question 40

Bupivacaine

Answer 40

narrow therapeutic index
never give IV!!
longer onset and duration

Question 41

Nocita

Answer 41

bupivacaine liposome injectable suspension
5.3 mg/kg
half life: 72 hours
used for infiltrative surgical incision anesthetic

Question 42

isotonic crystalloids

Answer 42

used to maintain hydration and to compensate for vasodilation, decrease in CO, or fluid loss
surgical rate: 1st hour 10 mL/kg, then 5 mL/kg
shock rate: dog 90 mL/kg, cat 60 mL/kg
bolus: 1/4 shock rate over 15-20 minutes

Question 43

colloids

Answer 43

aka plasma expanders
support expansion of blood volume or BP
synthetic rates: bolus 5 mL/kg over 20-30 minutes, CRI dog 10-20 mL/kg/day, cat 5-10 mL/kg/day
natural: used for anemia, hypoproteinemia, coagulation disorders, thrombocytopenia

Question 44

hypertonic saline

Answer 44

3%, 5%, 7%, 23.5%
used to treat hypovolemic, traumatic, or endotoxic shock and increase ICP
rapidly but temporarily draws water into the IVF space and increases BP
rapidly diffuses to the ISF space
usually given with colloid or crystalloids
3-4 mL/kg slow over 5-10 minutes
if given too fast can cause decreased BP, bradycardia, shallow tachypnea, bronchoconstriction