Exam 2: Lecture 9: Induction Drugs

Question 1

T/F: The ideal injectable drug should provide adequate and reliable sedation, analgesia, and muscle relaxation

Answer 1

true!

Question 2

T/F: We want our injectable drugs to cause minimal changes in cardiovascular or respiratory function as well has a wide safety margin

Answer 2

true!

Question 3

Should the idea injectable drug be reversible and have a rapid onset but long duration?

Answer 3

no, we want the drug to be reversible and have a rapid onset BUT it should also be short acting

Question 4

The ideal injectable drug should be readily _______ and _____ by the body

Answer 4

metabolized and excreted

Question 5

How long should the shelf like be for the ideal injectable drug

Answer 5

it should have a long shelf life and be stable in heat/light

Question 6

T/F: Ideal injectable drugs should be inexpensive and a controlled substance

Answer 6

false, it should be inexpensive BUT not controlled so there is less potential human abuse

Question 7

T/F: Ideal injectable drugs should require a large volume needed to achieve sedation

Answer 7

false, we should use a SMALL volume

Question 8

Describe the make up of propofol

Answer 8

milky white oil in water emersion….1% propofol, 10% soybean oil, 2.25% glycerol, and 1.2% egg phosphatide

Question 9

T/F: There are preservatives in propofol and it has a long life once opened

Answer 9

false, there are NO preservatives and the open vial should be discarded after 6 hours

Question 10

What is the name of the propofol that has benzyl alcohol preservatives to prevent bacterial fungal growth

Answer 10

Propofol28

Question 11

how long does propofol28 last once it is opened and is it approved for dogs and cats

Answer 11

28 days and no, only dogs

Question 12

describe the MOAo of propofol

Answer 12

activates GABAa receptors to increase Cl- conduction and blocks Na channels leading to hyperpolarization

Question 13

T/F: Propofol causes CNS depression and loss of consciousness

Answer 13

true

Question 14

What are the pharmacokinetics of propofol

Answer 14

rapid distribution followed by a slower clearance phase and rapid hepatic metabolism and excretion by kidneys

Question 15

T/F: You cannot use propofol as a CRI in many species

Answer 15

false, you can use as a CRI

Question 16

What 2 species/breeds do not rapidly metabolize propofol via hepatic system and do not excrete it by the kidneys

Answer 16

cats and greyhounds

Question 17

What happens to the CNS system with propofol (pharmacodynamics)

Answer 17

decreases intracranial pressure and cerebral metabolism of oxygen and has anticonvulsant effects

Question 18

T/F: Propofol is a reasonable choice for patients with head trauma

Answer 18

true! Due to the decrease of intracranial pressure

Question 19

What happens to the cardiovascular system with propofol (pharmacodynamics)

Answer 19

decreases BP due to vasodilation

Question 20

What comorbidities should we not use propofol with (3 things)

Answer 20

hypovolemia, advanced age, or decreases left ventricular function

Question 21

What happens to the respiratory system with propofol (pharmacodynamics)

Answer 21

dose-dependent respiratory depression and transient apnea (often with cyanosis)

Question 22

Finish this sentence: Rapid injection of propofol = ______ is more likely

Answer 22

apnea

Question 23

What happens to the musculoskeletal system with propofol (pharmacodynamics)

Answer 23

produces muscle relaxation, transient myoclonus (involuntary brief muscle contractions) can occur

Question 24

What happens to with fetal/neonatal system with propofol (pharmacodynamics)

Answer 24

crosses the placenta but is rapidly cleared from neonate, acceptable choice for dogs getting a c-section

Question 25

What are specific considerations for use of propofol in greyhounds

Answer 25

need same dose for induction but takes longer to recover

Question 26

What are specific considerations for use of propofol in cats

Answer 26

use caution with repeated daily use

Question 27

What are specific considerations for use of propofol in horses

Answer 27

rarely used for induction due to excitation and volume/cost but can be used as CRI, bolus intra-op, or facilitation of a smooth recover

Question 28

What are specific considerations for use of propofol in swine

Answer 28

does not induce malignant hyperthermia

Question 29

What are specific considerations for use of propofol in small ruminants and camelids

Answer 29

provides a smooth, rapid induction with a recovery that is good but need to consider cost for food animal

Question 30

Describe what drug was used for this clinical scenario: 1. induction dose is tritiated to effect given over 60-90 secs 2. swift induction in 20-30 secs 3. be ready to ventilate if needed 4. recovery in about 2-12 mins (dose and species dependent) 5. no analgesia 6. pain on infection esp in small vessels

Answer 30

propofol

Question 31

What is the definition of dissociative anesthetics

Answer 31

characterized by dissociation from thalamocortical (consciousness) and limbic (emotion/memory) leading to a change in awareness

Question 32

what is the main MOA of dissociative anesthetics

Answer 32

mainly act via antagonist effects at NMDA receptors

Question 33

what are the 7 other MOAs of dissociative anesthetics (other than NMDA)

Answer 33

1. AMPA 2. BDNF 3. opioid 4. endocannabinoid 5. monoaminergic receptors 6. muscarinic receptors 7. voltage-gated calcium channels

Question 34

What is important about ketamine and MOAs

Answer 34

ketamine has multiple MOAs that lead to its clinical effects

Question 35

What are the 2 most common dissociative anesthetics used

Answer 35

ketamine and tiletamine

Question 36

what 2 drugs make up telazol

Answer 36

tiletamine and zolazepam

Question 37

T/F: You can give dissociative anesthetics IM, IV, SQ, OTM, IN, or rectally

Answer 37

true!!

Question 38

what is the onset time (IV and IM) for dissociative anesthetics

Answer 38

IV = about 60 seconds IM = about 10 minutes

Question 39

How long on average do dissociative anesthetics last and how long does telazol last

Answer 39

7-23 minutes telazol = 35-70 mins

Question 40

T/F: Dissociative anesthetics are highly lipophilic but cannot cross the blood brain barrier

Answer 40

false, they ARE highly lipophilic and CAN cross the BBB

Question 41

How are dissociative anesthetics metabolized and excreted

Answer 41

metabolized = liver excreted = kidneys

Question 42

what is the active metabolite that cats can form when using dissociative anesthetics

Answer 42

nor ketamine, excreted unchanged in the urine

Question 43

In dogs, is tiletamine or zolazepam metabolized quicker

Answer 43

tiletamine > zolazepam

Question 44

In cats, is tiletamine or zolazepam metabolized quicker

Answer 44

zolazepam > tiletamine

Question 45

what happens to the CNS system when using dissociative anesthetics

Answer 45

cataleptic state of not being asleep but not responding to external stimuli

Question 46

what CNS signs do we see with emergence delirium when using dissociative anesthetics

Answer 46

ataxia, hyper-reflexive, sensitivity to touch, increase motor activity

Question 47

what happens to the cardiovascular system when using dissociative anesthetics

Answer 47

direct negative cardiac inotropic effects but usually overcome by sympathomimetic effects

Question 48

What are the sympathomimetic effects we see with dissociative anesthetics

Answer 48

increased BP, HR, cardiac output, myocardial oxygen requirements and cardiac work

Question 49

T/F: When using dissociative anesthetics, it inhibits NE reuptake to increase plasma catecholamines

Answer 49

true!

Question 50

What 2 cardiovascular comorbidites should we avoid using dissociative anesthetics

Answer 50

critically ill patients with decreased reserve (causes decreased BP) and in patients with severe cardiovascular disease

Question 51

what happens to the respiratory system when using dissociative anesthetics

Answer 51

does not cause significant respiratory depression

Question 52

What are the pharmacodynamics of the respiratory system with dissociative anesthetics

Answer 52

1. apneustic respiratory pattern 2. bronchial smooth muscle relaxant (bronchodilation) 3. pharyngeal and laryngeal reflexes remain intact

Question 53

what happens to the musculoskeletal system when using dissociative anesthetics

Answer 53

can cause muscle rigidity and spontaneous movements which can be diminished with use of benzo's

Question 54

what happens to intraoccular pressure during the use of ketamine

Answer 54

can increase due to increase tone of extraocular muscles

Question 55

what happens to the fetal/neonatal system when using dissociative anesthetics

Answer 55

crosses the placenta and should avoid using in c-section due to fetal depression

Question 56

What are specific considerations for use of dissociative anesthetics in dogs

Answer 56

combine ketamine with benzo for induction or can also use alpha-2 agonist or opioid

Question 57

What are specific considerations for use of dissociative anesthetics in cats

Answer 57

can spray into mouth of fractious cats because of absorption via oral mucosa

Question 58

What are specific considerations for use of dissociative anesthetics in horses

Answer 58

be sure to adequately sedate before induction and use ketamine with a benzo, alpha-2 agonist or guaifenesin telazol inductions are smooth but recovery is rough

Question 59

What are specific considerations for use of dissociative anesthetics in ruminants

Answer 59

combine ketamine with benzo or guaifensin and give a ketamine stun (sub-therapeutic dose of ketamine give prior to castration)

Question 60

What are specific considerations for use of dissociative anesthetics in swine

Answer 60

does not induce malignant hyperthermia, calm/slow recovery and not recommended for pot belly pigs

Question 61

T/F: ketamine is commonly administered with a benzodiazepine or alpha-2 agonist

Answer 61

true

Question 62

can you give ketamine as a CRI

Answer 62

yes at a sub-anesthetic dose to reduce inhalant requirements and provide analgesic effecrs

Question 63

T/F: ketamine and tiletamine are reversible

Answer 63

false! They are NOT reversible

Question 64

_____, ______, and _____ reflexes remain intact with ketamine or telazol

Answer 64

oral, ocular, and swallowing reflexes

Question 65

What was the historical problem with alfaxalone

Answer 65

it was poorly water soluble so older formations were combined with caster oil leading to histamine release and anaphylaxis in dogs

Question 66

Now a days, what is alfaxalone combined with

Answer 66

with non-cremophor vehicle to no longer cause histamine release and increases water solubility

Question 67

What are the 2 ways to give alfaxalone

Answer 67

IV or IM

Question 68

what is the shelf life of alfaxalone

Answer 68

56 days after vial is opened

Question 69

what is the MOA of alfaxalone

Answer 69

neuroactive steroid molecule that binds to GABAa receptor to increase Cl concentrations leading to hyperpolarization

Question 70

T/F: Alfaxalone has P450 hepatic metabolism and eliminated via kidneys

Answer 70

true

Question 71

what happens to the CNS when using alfaxalone

Answer 71

decreases cerebral blood flow, intra-cranial pressure, and CMRO2 (rate of O2 consumption via brain)

Question 72

what happens to the cardiovascular system when using alfaxalone

Answer 72

you have hemodynamic stability at clinically relevant doses but CAN cause dose-depended hypotension via vasodilation

Question 73

what happens to the respiratory system when using alfaxalone

Answer 73

dose-dependent respiratory depression and/or apnea

Question 74

what happens to the musculoskeletal system when using alfaxalone

Answer 74

relaxation

Question 75

what happens to the fetal/neonatal system when using alfaxalone

Answer 75

crosses placenta and causes dose-dependent fetal depression but is generally safe for c-sections

Question 76

Describe what drug was used: 1. NO Analgesia 2. used for induction usually but can be a CRI 3. safe for c-sections 4. good induction agent for at anesthetic risk dogs 5. can increase IOP 6. no pain on IV injection 7. schedule IV controlled substance 8. can cause excitement (cats), and vocalization (dogs) during recovery and usually has a ROUGH recovery in horses

Answer 76

alfaxalone

Question 77

What is the make up of etomidate and the pH

Answer 77

0.2% soln in 35% propylene glycol pH of 6.9

Question 78

T/F: Etomidate is soluble in water

Answer 78

FASE! insoluble in water

Question 79

what is the MOA of etomidate

Answer 79

enhances action of GABA (inhibitory) at GABAa receptor to increase Cl concentrations causes hyperpolarization

Question 80

What are the pharmacokinetics of etomidate

Answer 80

1. rapid penetration of brain leads to quick induction 2. rapid recovery 3. large therapeutic index 4. metabolism via liver and plasma esterases but excreted in urine

Question 81

what happens to the CNS when using etomidate

Answer 81

cerebroprotective effects, vasoconstriction of cerebral vessels, reduced CBF and CMRO2, decreases IOP and ICP

Question 82

what happens to the cardiovascular system when using etomidate

Answer 82

minimal to no changes in HR, SV, CO, MAP, and CVP Baroreceptors maintain function

Question 83

what happens to the respiratory system when using etomidate

Answer 83

minimal effects

Question 84

what happens to the endocrine when using etomidate

Answer 84

adrenocortical suppression (up to 6 hours in dogs and 5 hrs in cats)

Question 85

what happens to the musculoskeletal system when using etomidate

Answer 85

myoclonus or tremors can occur

Question 86

what happens to the fetal/neonatal system when using etomidate

Answer 86

minimal effects

Question 87

Describe what drug was used: 1. preferred induction agent in patients with hemodynamic instability, increased ICP or cirrhosis 2. NO analgesia 3. caution use in patients with addisons/highly stressed 4. not recommended as a CRI due to adrenocortical suppression 5. adequate premed 6. usually only in referral practices 7. can have pain on injection, vomiting, or excitement

Answer 87

etomidate

Question 88

When should we use mask or chamber inhalant inductions

Answer 88

for exotics or very aggressive patient where injectables are not possible

Question 89

What should we consider when using inhalants for induction

Answer 89

use caution due to exposure to personnel and potential harm to patient

Question 90

What is considered an "opioid induction"

Answer 90

ex - fentanyl + benzodiazepine

Question 91

what is "ketofol"

Answer 91

ketamine + propofol

Question 92

what is "double drip"

Answer 92

guaifenesin + ketamine

Question 93

what is "triple drip"

Answer 93

guaifenesin + ketamine + xylazine

Question 94

What drugs are "TKX" or "TKD"

Answer 94

telazol + ketamine + xylazine or dexmedetomidine

Question 95

1 yr F DSH for an OVH. weight = 4kg, BCS 4/9. Easy to handle and rexieved aq premed of ace + hydro IM about 30 mins ago. IVC has been placed. What induction agent should we use?

Answer 95

pretty much anything other than propofol28 (cant be used in cats)

Question 96

10 yr MN mini poodle who is 6kg for a dental cleaning +/- extractions. Hx of 3/6 heart murmur due to MV insufficiency. Currently on lasix and enalapril. What induction agent should we use?

Answer 96

etomidate if available... if not alfaxalone

Question 97

7 yr F greyhound presents for biopsy of 3cm mass over left shoulder. It is planned as an out patient procedure and owner wants to take her home ASAP. what induction agent should we use?

Answer 97

a ketamine based protocol would be best due to quick recover