Pre-anesthetic Medication and Induction Agents

Question 1

There are advantages and disadvantages to preanesthetic analgesia and sedation. What are 3 advantages?

Answer 1

1. Chemical restraint
2. Decreased stress + decreased catecholamines = Decreased risk of arrhythmia
3. Decreased induction and inhalant doses = Decreased dependent CV/respiratory depression
4. Pre-emptive analgesia

Question 2

There are advantages and disadvantages to preanesthetic analgesia and sedation. What are 3 disadvantages?

Answer 2

1. Bradycardia (opioids & alpha 2 agonists)
2. Hypotension (acepromazine)
3. Excitation (opioids & benxodiazepines)

Question 3

There are 5 Mu-opioid and kappa agonists. Name 3 of them.

Answer 3

1. Hydromorphone
2. Fentanyl
3. Morphine
4. Methadone
5. Oxymorphone

Question 4

What type of agonist is Buprenorphine?

Answer 4

Partial Mu agonist

Question 5

What type of agonist/antagonist is Butorphanol?

Answer 5

Mixed kappa agonist & mu antagonist

Question 6

What are the 2 reversal agents for opioid analgesics (hydromorphone, fentanyl, morphine, methadone, oxymorphone, butorphanol, buprenorphine)?

Answer 6

Naloxone & naltrexone

Question 7

Opioids can have mild cardiovascular effects. Which factor within the cardiovascular system is decreased by these drugs? What is increased to cause these effects?

Answer 7

Decreased heart rate due to increased vagal tone

Question 8

True or False: Opioids increase the MAC of an inhalant.

Answer 8

FALSE: Opioids decrease the MAC of an inhalant

Question 9

True or False: Opioids can cause respiratory depression.

Answer 9

TRUE

Question 10

Which opioid analgesic is a partial agonist?

Answer 10

Buprenorphine

Question 11

Which opioid analgesic is a mixed agonist/antagonist?

Answer 11

Butorphanol

Question 12

Which opioid analgesics are FULL mu-opioid agonists?

Answer 12

Hydromorphone, Fentanyl, Morphine, Oxymorphone, & Methadone

Question 13

True or False: Butorphanol has a “ceiling effect”.

Answer 13

TRUE

Question 14

Compared to mu-opioid agonists, Butorphanol elicits less what?

Answer 14

1. Panting
2. Bradycardia
3. Respiratory depression
4. Analgesia
5. Nausea (no vomiting)

Question 15

True or False: Buprenorphine has a “ceiling effect”.

Answer 15

TRUE

Question 16

In dogs and cats, what is the dose in mg/kg for Butorphanol?

Answer 16

0.2 - 0.4 mg/kg

Question 17

How long does sedation last under Butorphanol?

Answer 17

1 - 2 hours

Question 18

How long does sedation last under Buprenorphine?

Answer 18

Dogs: 4 - 10 hours

Cats: 6 - 12 hours

Question 19

Which of the following has a slow onset, Butorphanol or Buprenorphine? How long is that onset?

Answer 19

Buprenorphine: 30 - 45 minutes

Question 20

In small animals, what is the Buprenorphine dose in mg/kg?

Answer 20

0.1 - 0.4 mg/kg

Question 21

Compared to FULL mu-opioid agonists, Buprenorphine elicits less what?

Answer 21

1. Respiratory depression
2. Panting
3. Bradycardia
4. Analgesia
5. Nausea

Question 22

What is the duration of action of hydromorphone and oxymorphone?

Answer 22

2 - 4 hours

Question 23

What is the duration of action of morphine and methadone?

Answer 23

4 - 6 hours

Question 24

How long is Fentanyl’s duration of action?

Answer 24

Short: 15 to 30 minutes

Question 25

True or False: ALL full mu-opioid agonists cause nausea and vomting.

Answer 25

FALSE: Fentanyl does NOT cause vomiting

Question 26

Which of the mu agonists causes the greatest respiratory depression?

Answer 26

Fentanyl

Question 27

What type of agonist or antagonist is Acepromazine?

Answer 27

Alpha 1 antagonist

Question 28

What is the onset of action of Acepromazine? What is the duration?

Answer 28

Onset: 20 - 30 minutes Duration: 4 - 6 hours

Question 29

What are the cardiovascular side effects of Acepromazine?

Answer 29

Vasodilation Hypotension Bradycardia

Question 30

Which of the sedative/tranquilizer drugs is NON-REVERSIBLE?

Answer 30

Acepromazine

Question 31

True or False: Acepromazine causes seizures.

Answer 31

FALSE: Acepromazine may actually decrease the risk of seizure activity by decreasing excitation out of surgery

Question 32

What type of agonist or antagonist is Dexmedetomidine?

Answer 32

Alpha 2 agonist

Question 33

What is the time till onset of action for Dexmedetomidine? What is the duration?

Answer 33

Onset: 5 minutes Duration: 30 - 60 minutes

Question 34

What is the reversal agent for Dexmedetomidine?

Answer 34

Atipamazole

Question 35

For what type of patients would you reserve Dexmedetomidine?

Answer 35

Very painful, fearful, aggressive patients

Question 36

These alpha-2 agonists are used in horses: xylazine, detomidine, ad romifidine. What are their reversal agents?

Answer 36

Yohimbine & tolazoline

Question 37

For which patients should Benzodiazepines like Diazepam and Midazolam be reserved?

Answer 37

Pediatric and geriatric patients and the critically ill

Question 38

What is the reversal agent for Diazepam or Midazolam?

Answer 38

Flumazenil

Question 39

Diazepam contains propylene glycol, causing which 3 unwanted effects?

Answer 39

1. Pain on injection 2. Poor absorption 3. Toxicity at high doses

Question 40

What is the dosage for Midazolam to be given IM or IV?

Answer 40

0.1 - 0.2 mg/kg

Question 41

Atropine can be used for emergencies because of its quick onset of action. What is its time of onset IM and IV?

Answer 41

IM = 5 minutes IV = 1 minute

Question 42

How long is Atropine's duration of action?

Answer 42

60 - 90 minutes

Question 43

What is the onset of action for Glycopyrrolate? What is its duration?

Answer 43

Onset: 3 - 5 minutes Duration: 2 - 4 hours