Anesthesiology - Final Exam Material

Front 1

what are the three most common complications under inhalant anesthesia?

Back 1

1. hypotension
2. hypoventilation
3. hypothermia

Front 2

what is the most common complication under injectable anesthesia?

Back 2

hypoxia

Front 3

when do you treat arrhythmias under anesthesia?

Back 3

- if it is causing hemodynamic instability
- if it is going to cause further complications
- if the cause or the arrhythmia are treatable

Front 4

what two physiological parameters contribute to tissue oxygen delivery?

Back 4

1. arterial blood pressure
2. arterial blood O2 content

Front 5

what two physiological parameters contribute to arterial blood pressure?

Back 5

1. systemic vascular resistance
2. cardiac output

Front 6

what two physiological parameters contribute to cardiac output?

Back 6

1. heart rate
2. stroke volume

Front 7

what three physiological parameters contribute to stroke volume?

Back 7

1. preload
2. afterload
3. myocardial contractility

Front 8

what are three agents/conditions that can stimulate sinus bradycardia?

Back 8

1. opioids
2. hypothermia
3. vagal stimulation (push on eye, distend stomach with air)

Front 9

why can sinus bradycardia be bad under anesthesia?

Back 9

because it can cause hypotension → low perfusion

Front 10

what are two ways to treat sinus bradycardia under anesthesia?

Back 10

1. anticholinergics
2. warming

Front 11

why can sinus tachycardia be bad under anesthesia?

Back 11

- reduces ventricular filling time → ↓CO → hypoxia
- could indicate pain because anesthetic plane is too low

Front 12

how is sinus tachycardia under anesthesia treated?

Back 12

- find the cause (low plane?)
- analgesia
- increased depth

Front 13

what is a type 1 and type 2 2nd degree AV block?

Back 13

- Type 1: Wenckebach (beat-beat-pause-beat-beat-pause…)
- Type 2: a "regular" 2nd degree AV block

Front 14

when is a 2nd degree AV block normal under anesthesia?

Back 14

it is common in very fit horses

Front 15

what are two classes of anesthetics that can induce a 2nd degree AV block?

Back 15

1. α2 agonists
2. opioids

Front 16

how and when is 2nd degree AV block treated under anesthesia?

Back 16

- only if appropriate (e.g. hemodynamic effects)
- anticholinergics

Front 17

how is a 3rd degree AV block treated?

Back 17

pacemaker (will come up on a pre-op exam)

Front 18

what drug is bigeminy associated with?

Back 18

thiopental

Front 19

if you have to treat VPCs or V-tach, what is the drug of choice?

Back 19

lidocaine

Front 20

what drug is contraindicated with the presence of ventricular escape beats? What is the indicated drug class?

Back 20

- lidocaine contraindicated
- use anticholinergics to reestablish sinus rhythm

Front 21

what is an acceptable MAP for small animals? Large animals in recumbency?

Back 21

- small animals: 60 mmHg
- large animals: 70 mmHg

Front 22

what pAO2 is the in the danger zone

Back 22

60 mmHg

Front 23

what are three things in surgery that may cause hypotension?

Back 23

1. inhalent anesthetic agents
2. excessive depth
3. hemorrhage

Front 24

what are three clinical signs (without instruments) of hypotension?

Back 24

1. Tachycardia
2. Weak pulses(maybe)
3. Pale MM

Front 25

what are three things that you can administer to a patient to correct hypotension during anesthesia?

Back 25

1. fluids (crystalloids/colloids)
2. ± inotropes
3. ± vasopressors

Front 26

what SpO2 is mild hypoxia? What is severe?

Back 26

- mild: < 95%
- severe: < 90%

Front 27

when are the two most common times that we would see hypoxia?

Back 27

beginning and end of anesthesia

Front 28

what are three circumstances that you would see hypoxia in the maintenance phase of anesthesia?

Back 28

- tank runs out
- disconnected from breathing circuit
- obstruction

Front 29

what must happen to see cyanosis?

Back 29

5 g/dL of deoxyhemoglobin

Front 30

what are two circumstances when a cyanotic patient is well-ventilated?

Back 30

1. polycythemic patient (they have more blood and can easily overcome the 5 g/dL threshold)
2. anemic patients (especially small patients) may always be cyanotic

Front 31

what are four signs of hypoxia (and the cause) other than cyanosis and instrument measurements?

Back 31

1. Tachycardia (they need faster circulation to get oxygenated)
2. Arrhythmias (heart muscle deprived of oxygen)
3. Bradycardia (heart is deprived)
4. “Gasping” (agonal)

Front 32

what are five causes of hypoxemia?

Back 32

- Low FiO2 (fraction of inspired oxygen)
- V-Q mismatch (ventilation-perfusion mismatch; atelectasis)
- Shunt
- Hypoventilation (needs to be profound)
- Diffusion impairment

Front 33

what are five things to do when hypoxemia is suspected/confirmed?

Back 33

- Check your patient!
- Supply oxygen
- Intubation (do it / check it)
- Attempt to ventilate
- Check your machine

Front 34

why do oxygen levels not correlate with CO2 levels?

Back 34

oxygen levels do not correlate with CO2 levels, especially when the animal is being given supplemental oxygen. The animal has to be BREATHING to get rid of the CO2. The animal does not have to be breathing to have a good SpO2 if they are being supplied oxygen

Front 35

what are five ways to assess ventilation?

Back 35

- Respiratory rate
- Respiratory depth
- Respiratory pattern
- Blood gas (PaCO2)
- Capnography (EtCO2)

Front 36

what are two basic reasons why CO2 levels may be elevated in the blood?

Back 36

1. poorly eliminated
2. produced excessively

Front 37

- what is a normal pCO2?
- what is an "acceptable" high range of pCO2?

Back 37

- 35-45 mmHg (normal)
- 50-55 mmHg (acceptable)

Front 38

what are five clinical signs of hypercapnia/Hypercarbia?

Back 38

- Increased respiratory rate
- Tachycardia
- INCREASED BP
- Dark pink MMs
- Eventually, narcosis (sleepiness)

Front 39

what are five reasons why hypothermia is important?

Back 39

- DECERASES MAC OF INHALANT
- SHIVERING IS PAINFUL AND PHYSIOLOGICALLY EXHAUSTING
- Arrhythmias
- Delayed wound healing
- Prolonged recovery

Front 40

what are the four mechanisms of heat loss?

Back 40

1. conduction
2. convection
3. radiation
4. evaporation

Front 41

what are three characteristics of emergence excitement?

Back 41

1. disorientation
2. dysphoria
3. pain

Front 42

what are the three most important things to do to treat emergence excitement?

Back 42

1. TREAT PAIN
2. handle with care!
3. reassess

Front 43

what are the three organic functional groups of a typical local anesthetic?

Back 43

1. lipophilic portion (e.g. aromatic ring with a p-amino and carboxyl group)
2. hydrocarbon chain (e.g. ester or amide)
3. hydrophilic segment (e.g. tertiary amine)

Front 44

what are five ester local anesthetics?

Back 44

1. Procaine
2. Benzocaine
3. Chloroprocaine
4. Tetracaine
5. Cocaine

Front 45

what are three commonly used amide local anesthetics and four others?

Back 45

1. lidocaine
2. mepivacaine
3. bupivacaine
- etidocaine
- prilocaine
- levobupivacaine
- ropivacaine

Front 46

which local anesthetic has a fast onset (15 min) and moderate duration (1-2 hours)

Back 46

lidocaine

Front 47

which local anesthetic has a fast onset (15 min) and longer duration (1-2 hours), and is commonly used in lameness evaluation of the horse and not in small animals?

Back 47

mepivacaine

Front 48

which local anesthetic has a slow onset and long duration (1-2 hours), and is the primary local anesthetic used in the VTH for small animals and horses?

Back 48

bupivacaine

Front 49

what is the mechanism of local anesthetics?

Back 49

- blocks the ACVITVELY FIRING nerves of nerves ("frequency-dependent blockade")
- blocks the CLOSED and INACTIVATED Na channels
- prevents neuronal depolarization

Front 50

what aspect of a nerve determines its sensitivity to a local anesthetic?

Back 50

the amount of myelination. Less myelinated nerves are more sensitive than heavily myelinated nerves

Front 51

in what acid/base form are solutions of local anesthetics?

Back 51

in the protonated (i.e. hydrochloride salt) form

Front 52

why is the rate of absorption important with local anesthetics?

Back 52

Local anesthetics act locally, so absorption usually signals the end of their action

Front 53

if you do a ring block, what drug do you not want to mix with the local anesthetic and why?

Back 53

epinephrine, because it will vasoconstrict and cause the limb distal to the block to become ischemic

Front 54

why do ester local anesthetics generally last for a much shorter period of time than amide local anesthetics?

Back 54

- because pseudocholinesterases (ubiquitous) rapidly metabolize them
- amides are metabolized by hepatic CYP450 enzymes, which is a slower process

Front 55

why can amide based local anesthetics cause allergic reactions?

Back 55

because they are metabolized to PABA

Front 56

why shouldn't you give bupivacaine IV?

Back 56

because it is severely cardiotoxic

Front 57

which local anesthetic is neurotoxic?

Back 57

lidocaine

Front 58

what is the result of cardiotoxicity with a local anesthetic? How is it treated?

Back 58

- malignant arrhythmias
- treated with IV lipid administration

Front 59

which local anesthetic has been especially associated with methemoglobinemia?

Back 59

procaine (Cetacaine™)

Front 60

what are two good places where local anesthetics are absorbed when applied topically?

Back 60

- mucous membranes such as cornea and larynx

Front 61

local anesthetics absorb poorly through skin. What are two exceptions?

Back 61

1. EMLA cream
2. Lidoderm patch

Front 62

what should you always do before injecting local anesthetic into a patient?

Back 62

ASIPRATE

Front 63

how do you perform a "Bier block?"

Back 63

- Place IV Catheter
- Place Tourniquet
- Inject lidocaine
- Block is gone shortly after removal of tourniquet
- Time limited by tourniquet
- don't use bupivacaine!

Front 64

where are three sites to perform a regional block with local anesthetics?

Back 64

1. Epidural
2. Intrathecal
3. Brachial Plexus

Front 65

which local anesthetic is indicated for CRI? What animals is this contraindicated and why?

Back 65

- lidocaine
- not in cats because it lowers cardiac function

Front 66

why is intra-articular local anesthesia controversial?

Back 66

because it may be toxic to chondrocytes

Front 67

What is the definition of allodynia?

Back 67

Pain caused by a stimulus that does not normally provoke pain

Front 68

What is the definition of analgesia?

Back 68

Absence of pain in the presence of stimuli that would normally be painful

Front 69

What is the definition of hyperalgesia?

Back 69

An increased response to a stimulation that is normally not painful

Front 70

What is the definition of hypoalgesia?

Back 70

A diminished sensitivity to noxious stimulation

Front 71

What is the definition of inflammatory pain?

Back 71

Spontaneous pain and hypersensitivity to pain in response to tissue damage and inflammation

Front 72

What is the definition of multimodal analgesia?

Back 72

The use of multiple drugs with different actions, which may act at different levels of the nociceptive pathways, to produce optimal analgesia

Front 73

What is the definition of neuropathic pain?

Back 73

Pain originated from an injury or that involves peripheral or central nervous system and is described as burning or shooting, possibly
associated with motor, sensory, or autonomic deficits

Front 74

What is the definition of nociception?

Back 74

The reception, conduction and central nervous system processing of nerve signals generated by the stimulation of nociceptors. This process leads to the perception of pain

Front 75

What is the definition of physiologic pain?

Back 75

Protective mechanism to make individuals move away from the cause of potential tissue damage or to avoid movement or contact with external stimuli during a reparative phase

Front 76

What is the definition of preemptive analgesia?

Back 76

Administration of analgesics drugs before stimulation to prevent sensitization of neurons and windup, thus reducing postoperative pain

Front 77

What is the definition of somatic pain?

Back 77

Pain originated from injury of bones, joints, muscle, or skin and is usually localized, constant, sharp, aching and throbbing

Front 78

What is the definition of visceral pain?

Back 78

Pain originated from stretching, distention or inflammation of the viscera, and is usually deep, cramping, aching or gnawing, and poorly localized

Front 79

What is the definition of windup?

Back 79

Sensitization of nociceptors and peripheral and central pain pathways in response to an overwhelming quantity of afferent nociceptive impulses resulting in expanded receptive fields and an increased rate of discharge

Front 80

Pain caused by a stimulus that does not normally provoke pain is called what?

Back 80

allodynia

Front 81

Absence of pain in the presence of stimuli that would normally be painful is called what?

Back 81

analgesia

Front 82

An increased response to a stimulation that is normally painful is called what?

Back 82

hyperalgesia

Front 83

A diminished sensitivity to noxious stimulation is called what?

Back 83

hypoalgesia

Front 84

Spontaneous pain and hypersensitivity to pain in response to tissue damage and inflammation is called what?

Back 84

inflammatory pain

Front 85

The use of multiple drugs with different actions, which may act at different levels of the nociceptive pathways, to produce optimal analgesia is called what?

Back 85

multimodal analgesia

Front 86

Pain originated from an injury or that involves peripheral or central nervous system and is described as burning or shooting, possibly associated with motor, sensory, or autonomic deficits is called what?

Back 86

neuropathic pain

Front 87

The reception, conduction and central nervous system processing of nerve signals generated by the stimulation of nociceptors. This process leads to the perception of pain" is called what?

Back 87

nociception

Front 88

Protective mechanism to make individuals move away from the cause of potential tissue damage or to avoid movement or contact with external stimuli during a reparative phase is called what?

Back 88

physiologic pain

Front 89

Administration of analgesics drugs before stimulation to prevent sensitization of neurons and windup, thus reducing postoperative pain is called what?

Back 89

preemptive analgesia

Front 90

Pain originated from injury of bones, joints, muscle, or skin and is usually localized, constant, sharp, aching and throbbing is called what?

Back 90

somatic pain

Front 91

Pain originated from stretching, distention or inflammation of the viscera, and is usually deep, cramping, aching or gnawing, and poorly localized is called what?

Back 91

visceral pain

Front 92

Sensitization of nociceptors and peripheral and central pain pathways in response to an overwhelming quantity of afferent nociceptive impulses resulting in expanded receptive fields and an increased rate of discharge is called what?

Back 92

windup

Front 93

what is the three-fold chain of neurons in the nociceptive pathway and where do these neurons project?

Back 93

1. First order neuron: starting at the periphery and projecting to the spinal cord
2. Second order neuron: cross the spinal cord and ascend to the brain
3. Third order neuron: projects into the cerebral cortex and other supraspinal structures

Front 94

which types of neurons are involved in nociception?

Back 94

Free A-delta and C nerve endings

Front 95

A-delta nociceptors:
- what types of stimuli are they sensitive to?
- what are the two types?
- how fast do they discharge compared to C-fiber nociceptors?
- what type of information do they provide to the CNS?
- what is an example of they painful feelings they transduce?

Back 95

- Composed of mechanoreceptors and mechanothermal receptors
- Low-threshold (<75%); High-threshold (<25%): respond only to tissue-damaging stimulation
- Discharge at a higher rate than C-fiber nociceptors
- Provide more discriminative information to the Central Nervous System
- Responsible for pricking and sharp qualities of “First Pain”

Front 96

C-fiber nociceptors:
- comment on the threshold and type of stimuli they are responsive to
- what type of pain do they produce?
- what is an example of the painful feelings they transduce?
- what higher-level behaviors in the CNS do they activate?

Back 96

- Almost all are High-threshold and respond to different types of stimulation (polymodal)
- Activation is responsible for slow-onset (“second”) pain that occurs after the initial insult.
- Burning and aching qualities
- Signals tissue damage and inflammation that initiates self-preservation behaviors such as avoidance and guarding and disuse.

Front 97

What are the four steps of the pain pathway?

Back 97

1. transduction
2. transmission
3. modulation
4. perception

Front 98

A-delta fibers:
- diameter
- myelination
- conduction speed
- type of pain
- timing of the pain with respect to other pathways

Back 98

- Small diameter 1-4 μM
- Myelinated
- Fast conduction
- Transmit well localized pricking, sharp pain
- “First pain”.

Front 99

C-fibers:
- diameter
- myelination
- conduction speed
- type of pain
- timing of the pain with respect to other pathways

Back 99

- Smaller diameter 0.4 – 1.2 μM
- Unmyelinated
- Slow conduction
- Transmit poorly localized dull or aching pain
- “Second pain”

Front 100

amplification or suppression of the peripheral sensory nerve impulses at the level of the spinal cord is called what?

Back 100

modulation

Front 101

what is pain modulation?

Back 101

amplification or suppression of the peripheral sensory nerve impulses at the level of the spinal cord

Front 102

What is end result of neuronal activity of pain transmission, where pain becomes a conscious multidimensional experience?

Back 102

perception

Front 103

what is pain perception?

Back 103

end result of neuronal activity of pain transmission. Pain becomes a conscious multidimensional experience

Front 104

what are the three cortical areas involved in pain perception?

Back 104

1. reticular system
2. somatosensory cortex
3. limbic system

Front 105

what are three neurotransmitters involved in peripheral sensitization of pain (primary hyperalgesia)?

Back 105

1. Substance P
2. Neurokinin A
3. Calcitonin gene related peptide (CGRP)

Front 106

what are four physiologic responses to neurotransmitters involved in peripheral sensitization and primary hyperalgesia?

Back 106

1. Excitability of sensory and sympathetic fibers
2. Vasodilation
3. Extravasation of plasma proteins
4. Recruitment of inflammatory cells

Front 107

what is the "sensitizing soup"

Back 107

a group of cytokines, neurotransmitters, and other autacoids involved in secondary hyperalgesia

Front 108

what is secondary hyperalgesia?

Back 108

a lower response threshold for A-delta and C-fiber activation (activation of silent nociceptors) in an expanded area around the site of primary pain sensitization

Front 109

what is the physiologic process of "wind-up"? (4 steps)

Back 109

1. NMDA receptor activation
2. Ca influx
3. Activation of protein kinase C
4. Increased sensitivity to glutamate

Front 110

where does "wind-up" occur?

Back 110

dorsal horn of the SC

Front 111

how does pain affect the immune system?

Back 111

Increased cortisol levels impair wound healing and decrease immune system function

Front 112

how does pain affect the neuroendocrine system? (3)

Back 112

- Activated by Pain
- Gluconeogenesis is favored
- Impaired metabolism results in catabolism and cachexia

Front 113

how does pain affect the GI system?

Back 113

Sympathetic stimulation can cause shunting of blood, decreased motility, and decreased mucosal integrity

Front 114

how does pain affect the CV system?

Back 114

Activation of RAAS:
- fluid retention
- elevated blood pressure
- decreased renal perfusion
- Increased HR, SV, CO and myocardial O2 consumption.

Front 115

what are some clinical signs in animals that have loss of normal behavior due to pain?

Back 115

- Decreased ambulation or activity
- lethargic attitude
- decreased appetite
- decreased grooming (cats)
- Harder to assess in the hospital

Front 116

what are some examples of abnormal behaviors associated with pain?

Back 116

- Inappropriate elimination
- Vocalization
- Aggression
- Decreased interaction with other pets or family members
- Altered facial expression
- Altered posture
- Restlessness
- Hiding (especially in cats)

Front 117

generally, how does an animal in pain react to touch?

Back 117

Increased body tension or flinching in response to gentle palpation of injured area and palpation of regions likely to be painful, e.g., neck, back, hips, elbows

Front 118

what are four physiologic parameters that may be elevated as a result of pain?

Back 118

1. Heart rate
2. Respiratory rate,
3. Body temperature
4. Blood pressure

Front 119

when an animal is in pain, what do their pupils do?

Back 119

dilate

Front 120

what are six types of scales for pain assessment?

Back 120

1. simple descriptive scale
2. visual analog scale
3. numerical rating scale
4. dynamic and interactive visual analog scale
5. University of Melbourne Pain Scale (UMPS)
6. Glasgow Composite Measures Pain Scale

Front 121

what are the four steps in the Dynamic and Interactive Visual Analog Scale (DIVAS) of pain assessment?

Back 121

1. Observation from a distance undisturbed
2. Approached, handled, encourage to walk
3. Palpation of surgical incision and surrounding area
4. Final overall assessment of sedation and pain

Front 122

what is considered to be the most accurate scale of pain assessment in animals?

Back 122

The Glasgow Composite Measures Pain Scale

Front 123

what are the six parameters assessed in the SHORT FORM Glasgow Composite Measures Pain Scale?

Back 123

1. vocalization
2. mobility
3. demeanor/response to humans
4. attention to wound
5. response to touch
6. posture and comfort

Front 124

how do you differentiate pain from dysphoria?

Back 124

- pain with interaction: can be temporarily distracted or calmed; doses of opioids help; there is an identifiable source of pain
- dysphoria: difficult to distract or calm; DOSES OF OPOIDS DO NOT HELP; no identifiable source of pain

Front 125

what are four basic ways to modify the nervous system to provide analgesia?

Back 125

1. inhibit perception
2. modulation of spinal pathways (inhibit central sensitization)
3. inhibit transmission (inhibit impulse conduction)
4. inhibit transduction (inhibit peripheral sensitization of nociceptors)

Front 126

what are four drug classes that inhibit pain perception?

Back 126

1. anesthetics
2. opioids
3. α2-agonists
4. benzodiazepines

Front 127

what are two classes of drugs that inhibit transmission of pain through the nerves?

Back 127

1. local anesthetics
2. α2-agonists

Front 128

what are three classes of drugs that inhibit pain transduction (i.e. inhibits peripheral sensitization of nociceptors)

Back 128

1. NSAIDs
2. opioids
3. local anesthetics

Front 129

what are seven classes of drugs that inhibit modulation of spinal pathways of pain (inhibit central sensitization)?

Back 129

1. local anesthetics
2. opioids
3. α2-agonists
4. tricyclic antidepressants
5. cholinesterase inhibitors
6. NMDA antagonists
7. NSAIDs

Front 130

what severity of pain are treated with opioid:
- mu-agonists?
- partial mu-agonists?
- agonists-antagonists?

Back 130

- mu-agonists: moderate to severe
- partial mu-agonists: mild to moderate
- agonists-antagonists: mild

Front 131

name six mu agonists used as analgesics

Back 131

1. morphine
2. oxymorphone
3. fentanyl
4. hydromorphone
5. methadone
6. meperidine

Front 132

name a partial mu agonist used as an analgesic

Back 132

buprenorphine

Front 133

name an opioid agonist-antagonist used as an analgesic for mild pain

Back 133

butorphanol

Front 134

name six COX-2 NSAIDS

Back 134

1. Meloxicam (Metacam)
2. Carprofen (Rimadyl)
3. Etodolac (Etogesic)
4. Deracoxib (Deramaxx)
5. Firocoxib (Previcox)
6. Tepoxalin (Zubrin)

Front 135

what are six contraindications of NSAID administration?

Back 135

1. renal or hepatic insufficiency
2. low effective circulating volume (dehydration, hypotension, shock)
3. active GI disease
4. coagulopathies
5. concurrent use of corticosteroids or other NSAIDs
6. pregnancy

Front 136

what are two cons of using α2-agonists as analgesics for long-term use?

Back 136

1. low doses still have a CV effect
2. short duration of drug (CRI may be needed)

Front 137

lidocaine as an IV analgesic
- site of action
- mechanism of action
- what animal (disease) is this commonly used?
- complications of lidocaine under anesthesia

Back 137

- inhibits spontaneous impulses from injured nerve and from dorsal root ganglion
- NMDA receptor antagonism (neuropathic pain)
- good visceral analgesia in horses (colic)
- decreases MAC about 25% for inhalant anesthetics

Front 138

low dose ketamine as an analgesic
- mechanism of action
- why is this good for burn victims?
- routes of administration

Back 138

- blocks glutamate at NMDA receptor
- good for burns because it treats central sensitization and hyperalgesia
- IV, SQ, IM, epidural

Front 139

when is it appropriate to give analgesia to prevent hypersensitivity and the lowest amount of post-operative pain?

Back 139

before, during, and after surgery

Front 140

what is an advantage of CRI opioid administration over bolus?

Back 140

pain relief without the sedation/euphoria/dysphoria at the peak and without the returning pain/hypersensitization/tolerance at the trough

Front 141

what opioid is commonly given transmucosally?

Back 141

buprenorphine

Front 142

what is an advantage of giving opioids transmucosally versus orally?

Back 142

no first-pass effect

Front 143

which opioid is commonly given transdermally?

Back 143

fentanyl

Front 144

which two types of analgesics are given intraarticularly?

Back 144

local anesthetics and opioids

Front 145

what are four nerves in the head to block when you would want to do dental work?

Back 145

1. infraorbital
2. maxillary
3. inferior alveolar
4. mental

Front 146

what is a common analgesic drug cocktail that is given intraoperatively and also post-operatively?

Back 146

FLK: fentanyl, lidocaine, ketamine

Front 147

what are four opioids commonly given pre-operatively?

Back 147

morphine, hydromorphone, oxymorphone, fentanyl

Front 148

in chemical restraint, what is required for ruminants to become recumbent? Horses?

Back 148

- ruminants: sedation
- horses: they need anesthesia

Front 149

chemical restraint comment on fasting for field procedures in:
- equine
- bovine
- alpaca/llama/ovine/caprine

Back 149

- equine: not necessary
- bovine: if prolonged recumbency, 48-72h or solid food and 24h of liquid restriction; short recumbency: 24h of fasting
- alpaca/llama/ovine/caprine: 24h of food and 13h of water restriction

Front 150

what are two reasons why are large animals (except horses) fasted before chemical restraint?

Back 150

1. risk of regurgitation/aspiration
2. tympanism/hypoventilation/hypoxemia

Front 151

what are five signs of sedation in large animals?

Back 151

- Head drop
- Droopy eyes
- Droopy lips
- Increase distance between feet
- Ataxia

Front 152

what is the major mechanism of action of acepromazine with regards to using it for standing restraint in large animals?

Back 152

inhibits dopamine receptors in the brain

Front 153

why is acepromazine good for sedation (i.e. chemical restraint), but not for anesthesia, when used alone?

Back 153

because it has a "ceiling effect", where you reach a maximum efficacy, but the side-effects keep increasing with increasing dose.

Front 154

what is the onset and duration of acepromazine when used as chemical restraint?

Back 154

- onset: 20-30 min
- duration, up to 5 hours

Front 155

what is the reversal agent for acepromazine when used for standing restraint?

Back 155

there is none

Front 156

what is a problem with acepromazine in stallions?

Back 156

priapism

Front 157

which large animal chemical restraint drug produces less ataxia than α2-agonists and is good for transporting animals?

Back 157

acepromazine

Front 158

acepromazine is not effective in what species?

Back 158

swine

Front 159

which sedative also can be used as a vasodilator to improve hoof circulation?

Back 159

acepromazine

Front 160

what is the biggest problem with oversedation in large animals (e.g. using α2 drugs in chemical restraint)?

Back 160

it is harder to move the animal

Front 161

comment on the use of α2 agonists in standing restraint on its effects on:
- muscles
- pain
- coordination
- GI
- renal

Back 161

- muscle relaxation
- analgesia
- ataxia
- decreased GI motility
- diuresis

Front 162

what is the most common reversal agent in standing restraint used with xylazine?

Back 162

yohimbine

Front 163

what are three α2 reversal agents used in standing restraint?

Back 163

yohimbine, atipemazole, tolazoline

Front 164

what are three important side effects of α2 agonists when used in standing restraint?

Back 164

1. hypertension
2. bradycardia
3. arrhythmia

Front 165

what is the only FDA approved α2 reversible agent for use in veterinary patients?

Back 165

tolazoline

Front 166

for standing restraint in field procedures, by what route of administration is xylazine administered to:
- horses?
- cattle?

Back 166

- horses: IV
- cattle: IM

Front 167

what is an important side-effect of xylazine in cows?

Back 167

induces abortion in late gestation

Front 168

what is a good sedative to control pain in severe colics?

Back 168

xylazine

Front 169

which α2 agonist can be given through the oral mucosa in aggressive or needle-shy horses?

Back 169

detomidine

Front 170

what is a good way to cause a seizure in a horse with α2 drugs?

Back 170

inject into their carotid artery by mistake instead of the jugular

Front 171

what is an important side-effect of xylazine in sheep?

Back 171

acute pulmonary edema

Front 172

detomidine in standing restraint of horses:
- compare to xylazine with respect to sedation and analgesia effects
- onset and duration
- what is a disadvantage post-op?
- what side-effect is stronger in this drug versus xylazine?

Back 172

- better sedation, and sedation lasts longer than analgesia
- onset: 5-7 min; duration ≈ 45 min
- can mask surgical colic
- more CV depression than xylazine

Front 173

what are two advantages of romifidine over other α2 drugs in standing restraint of the horse?

Back 173

1. less head drop than xylazine and detomidine
2. less ataxia than other α2 drugs

Front 174

what is the proper route to give xylazine reversal agents and why?

Back 174

IM, because IV administration can cause CV instability

Front 175

which opiod in standing restraint is most commonly used and is good for visceral pain?

Back 175

butorphanol

Front 176

butorphanol in standing restraint:
- what is a side-effect in horses that are not painful and/or not sedated?
- which receptors does it interact with and how?
- why might it be used with morphine?
- what is an advantage of giving this drug IV versus morphine?
- compare to morphine with respect to GI tract stasis

Back 176

- can cause excitement in not sedated/not painful horses
- kappa-agonist; mu-ANTAGONIST
- used with morphine to antagonize some of the μ-effects while preserving some analgesia
- does not release histamine with IV injection; morphine does
- less GI tract stasis versus morphine

Front 177

why is guaifenesin only used IV with chemical restraint?

Back 177

because extravascular injection causes tissue necrosis

Front 178

guaifenesin for chemical restraint:
- effects on CV and respiratory
- degree of analgesia
- risk if too concentrated
- route of administration

Back 178

- minimal CV and respiratory effects
- no analgesia
- can cause hemolysis if concentration is too high
- administered IV only (necrosis) as a fast bolus and/or CRI

Front 179

what is the most common agent used in horses for field procedures?

Back 179

ketamine

Front 180

what is a common analgesic drug cocktail that is given to horses for field procedures or a triple-drip during anesthesia?

Back 180

KGX: ketamine, guaifenesin, xylazine

Front 181

what are two complications of large animals in recumbency?

Back 181

1. myopathy
2. tympanism in ruminants that have not been adequately fasted

Front 182

what is the mortality rate of horses under general anesthesia?

Back 182

1%

Front 183

what are three common sedative/analgesic combinations used for horses pre-op?

Back 183

1. Acepromazine ± alpha-2 agonists ± opioid
2. Acepromazine + opiod
3. Alpha-2 agonists ± opioid

Front 184

why should you give morphine diluted and slowly, while observing the BP of a horse?

Back 184

because it can cause histamine release when given IV

Front 185

why should morphine be given with an α2 drug in horses for pre-op sedation?

Back 185

because morphine alone can cause excitement

Front 186

what is the most important thing to be sure of before you give horse anesthesia?

Back 186

ADEQUATE SEDATION

Front 187

what two injectable anesthetics should you not use in horses?

Back 187

propofol and etomidate

Front 188

what class of drugs is most commonly given to horses to induce anesthesia?

Back 188

dissociatives (e.g. ketamine)

Front 189

what happens if you accidentally inject ketamine perivascularly?

Back 189

nothing

Front 190

how do horses differ from donkeys and mules with injectable anesthetics?

Back 190

donkeys and mules require more frequent dosing

Front 191

comment on the depth of anesthesia in the horse if the horse is/has:
- blinking
- fast nystagmus
- slow nystagmus
- a strong palpebral reflex

Back 191

- blinking: too light
- fast nystagmus: too light
- slow nystagmus: ok; assess other parameters
- strong palpebral reflex: this is normal under adequate anesthesia

Front 192

Telazol:
- onset and duration
- induction quality
- use maintenance
- recovery quality

Back 192

- onset: up to 2 minutes; duration 15-45 minutes
- good induction quality: smoother drop to ground, which is especially good for orthopedic patients
- usually you would re-dose with ketamine
- recovery can be rough due to excitement; re-dosing with ketamine will give a smoother recovery

Front 193

what horses can you use propofol as induction agents?

Back 193

foals

Front 194

what is a long list of induction drug combinations for horses?

Back 194

- Telazol (tiletamine + zolazepam)
- Ketamine + diazepam (or midazolam)
- Ketamine + GG
- Ketamine (with high dose xylazine sedation)
- Thiopental
- Thiopental + GG
- Propofol (foals)
- Propofol + Ketamine (foals)

Front 195

inhalants in horse anesthesia
- advantages
- degree of muscle relaxation
- degree of analgesia
- CV and respiratory effects
- why is this tough to do in the field?

Back 195

- advantages: Easier to control depth of anesthesia, Very little metabolisation
- Good muscle relaxation
- NOT analgesics
- Profound CV and respiratory depression
- field: Require anesthesia machine, which is not feasible

Front 196

what is a big difference between an anesthesia machine that you would use on a dog versus a horse?

Back 196

the horse anesthesia machine must be capable of much higher flow rates

Front 197

what is the most popular analgesic used with horse inhalant general anesthesia? Why is it so popular?

Back 197

- lidocaine
- enhances the anesthesia (e.g. ↓MAC) and ↑GI motility

Front 198

what are five drugs that are used as analgesics and enhancers of inhalent anesthesia in the horse?

Back 198

1. morphine
2. lidocaine
3. butorphanol
4. xylazine
5. ketamine

Front 199

describe the following signs of LIGHT anesthesia in the horse:
- corneal reflex
- palpebral reflex
- lateral nystagmus
- unstimulated blinking
- eyeball position
- tear production

Back 199

- corneal reflex: brisk
- palpebral reflex: brisk
- lateral nystagmus: present
- unstimulated blinking: present
- eyeball position: centered
- tear production: present

Front 200

describe the following signs of ADEQUATE anesthesia in the horse:
- corneal reflex
- palpebral reflex
- lateral nystagmus
- unstimulated blinking
- eyeball position
- tear production

Back 200

- corneal reflex: present
- palpebral reflex: slowed
- lateral nystagmus: absent
- unstimulated blinking: absent
- eyeball position: rotated (not in every horse)
- tear production: absent

Front 201

describe the following signs of DEEP anesthesia in the horse:
- corneal reflex
- palpebral reflex
- lateral nystagmus
- unstimulated blinking
- eyeball position
- tear production

Back 201

- corneal reflex: absent
- palpebral reflex: absent
- lateral nystagmus: absent
- unstimulated blinking: absent
- eyeball position: centered
- tear production: absent

Front 202

what are four reasons why you want to use an invasive blood pressure monitor in horses under general anesthesia?

Back 202

- leading cause of death is CV collapse
- high incidence of myositis in horses
- keep above 70 mmHg
- blood pressure spikes before eye changes when they wake up

Front 203

what is an advantage and a disadvantage to providing positive pressure ventilation to the horse during anesthesia?

Back 203

- prevents atelectasis
- causes CV depression

Front 204

what is the preferred positive inotrope type to use in horses under general anesthesia?

Back 204

β-agonists (versus α1 agonists)

Front 205

what is the preferred specific positive inotrope given to horses under general anesthesia

Back 205

dobutamine (versus dopamine, vasopressin, or norepinephrine)

Front 206

what are six things to do/give to the horse during recovery from general anesthesia?

Back 206

1. Sedation
2. Oxygen
3. Airway support (Oral or nasal tube)
4. Empty bladder
5. Cover eyes
6. Nasal decongestion (vasoconstrictors)

Front 207

what are eight complications of general anesthesia in the horse?

Back 207

1. Hypotension/CV collapse
2. Hypoventilation
3. V/Q mismatch
4. Myopathy
5. Nerve paralysis
6. Fractures
7. Airway obstruction (nasal swelling)
8. Excitement

Front 208

fasting for bovine anesthesia:
- adults
- milk-fed calves

Back 208

- Adults 18-24 hours if possible
- Milk-fed calves just a few hours

Front 209

what are three common sedation protocols for bovine pre-op?

Back 209

1. Alpha-2 agonist – REMEMBER LOWER DOSE
2. Alpha-2 agonist + butorphanol
3. Alpha-2 agonist + ketamine

Front 210

what are the two most common local anesthetics given to bovines?

Back 210

1. lidocaine
2. bupivacaine

Front 211

what are five bovine injectable anesthesia protocols?

Back 211

1. Ketamine
2. Ketamine + Diazepam
3. Ketamine + GG
4. Thiopental
5. Thiopental + GG

Front 212

normal parameters of bovine inter-operative anesthesia:
- HR
- RR
- eye position
- BP

Back 212

- HR: 60-80 beats per minute
- RR: 20-30 breaths per minute
- Eye position: Ventral rotation indicates surgical anesthetic depth; Central position could indicate too light OR too deep (!)
- Blood pressure: same as other mammals; Normotension is important to prevent myopathy

Front 213

what are five potential complications during bovine general anesthesia?

Back 213

1. tympany
2. regurgitation (don't use atropine)
3. hypoventilation
4. movement
5. hypotension

Front 214

comment on using dobutamine in the bovine during anesthesia

Back 214

they are VERY sensitive to it's tachycardic effects

Front 215

bovine recovery from general anesthesia:
- optimal position
- excitement
- when do you extubate?

Back 215

- sternal ASAP
- little to no excitation on recovery
- extubate only when they have good airway control

Front 216

what are five things that make small ruminant general anesthesia a pain in the ass?

Back 216

1. very narrow dental arcade
2. relatively long face and thick tongue
3. they regurgitate often
4. they may bloat
5. eye position is less useful than pupil size and shape

Front 217

comment on the problem of regurgitation of small ruminants under anesthesia:
- plane of anesthesia at induction
- type of tube
- use of atropine

Back 217

- you may need to make them "deeper" at induction to reduce regurgitation
- use a cuffed ET tube
- don't use atropine; it just makes secretions thicker

Front 218

what are three common complications of small ruminant general anesthesia?

Back 218

1. hypoxia
2. rumen tympany
3. hypotension

Front 219

what are two sedation/analgesia protocols for the small ruminant?

Back 219

1. Alpha-2 agonist
2. Alpha-2 agonist + opioid

Front 220

what are four injectable induction protocols in the small ruminant?

Back 220

1. Ketamine + Diazepam
2. Telazol
3. Thiopental
4. Propofol (smaller animals)

Front 221

what is the best way to make sure that a small ruminant is properly intubated?

Back 221

capnograph

Front 222

small ruminant recovery from general anesthesia:
- optimal position
- excitement
- when do you extubate?

Back 222

- maintain sternal recumbency
- usually no excitation
- extubate when they are swallowing effectively

Front 223

which two types of large animals are obligate nasal breathers?

Back 223

horses and camelids

Front 224

what is an extremely important thing to be sure of when anesthetizing a camelid?

Back 224

accurate weight

Front 225

what is the preferred sedation/analgesia protocol for camelids, what are two others?

Back 225

- α2 and buprenorphine (preferred)
1. xylazine
2. α2 + butorphanol

Front 226

what two injectable drugs can cause perivascular necrosis?

Back 226

thiopental and guaifenesin

Front 227

what are three injectable induction protocols for camelids?

Back 227

1. Ketamine + Diazepam
2. Propofol (smaller animals)
3. Thiopental

Front 228

camelid anesthesia maintenance:
- HR
- RR
- BP
- eye position

Back 228

- HR: 40-80 bpm
- RR: 20 bpm
- BP: same as other mammals
- eye position: less useful; pupil size and shape are more indicative

Front 229

comment on eye position with camelids under general anesthesia:
- palpebral reflex
- spontaneous blink
- nystagmus

Back 229

- palpebral reflex: maintained at adequate depth
- spontaneous blink: too light
- nystagmus: not usually visible

Front 230

what do camelids tend to do during recovery that is weird?

Back 230

Curl necks backward and swing head during recovery

Front 231

how long should an adult pig be fasted before anesthesia?

Back 231

12-24 hours

Front 232

where is an IV catheter placed in a pig?

Back 232

ear vein

Front 233

what is different about the trachea of a pig (with regard to intubation) versus other animals?

Back 233

it makes a dorsal bend at the level of the laryngeal vestibule, so the tube must be manipulated to get good intubation

Front 234

what are the four steps of intubating a pig?
- position
- arytenoid visualization and treatment
- ET tube specifics
- technique to pass the tube

Back 234

- Sternal recumbency, neck stretched up, mouth open with gauze
- Laryngoscope to visualize arytenoids, & spray lidocaine
- ET tube with stylet bent at tip into a curve
- Pass tube until you meet resistance, then turn 180 up, advance, and turn back down

Front 235

what are two breeds of pigs predisposed to malignant hyperthermia?

Back 235

Landrace and Duroc

Front 236

what triggers malignant hyperthermia in pigs?

Back 236

stress, depolarizing muscular blockers, inhalants (esp. halothane)

Front 237

how do you treat malignant hyperthermia in the anesthetized pig?

Back 237

- remove all inhalant
- actively cool the pig
- ventilate
- ± dantrolene (supposedly stabilized Ca release from the SR)

Front 238

what are four complications of anesthesia in the pig?

Back 238

1. malignant hyperthermia
2. regurgitation
3. hypothermia (no hair!)
4. hypotension (same likelihood as other animals)

Front 239

comment on recovery of swine from anesthesia:
- temp
- smoothness

Back 239

- monitor temperature closely; warming often needed
- recovery is generally smooth

Front 240

which sedative is not very good for use in swine?

Back 240

acepromazine

Front 241

what are four premed/sedative protocols for swine general anesthesia?

Back 241

1. Telazol
2. Telazol + xylazine
3. Ketamine ± midazolam ± butorphanol
4. Also Telazol, ketamine, xylazine (TKX) – but this takes them deeper, in between premed and induction

Front 242

what are four injectable induction protocols used in swine?

Back 242

1. Ketamine ± diazepam
2. Propofol (smaller animals)
3. Telazol
4. Thiopental – phlebitis in small vessels

Front 243

what are two physiologic characteristics of the cat that complicates anesthesia in them versus dogs?

Back 243

1. hepatic enzyme deficiencies
2. laryngospasm

Front 244

fasting for general anesthesia in the cat:
- adults
- young kittens

Back 244

- adults: 8-12 hours
- kittens: 1-2 hours

Front 245

why is UA important in the feline pre-op exam?

Back 245

because renal failure is common

Front 246

how long does it take lidocaine to relax the arytenoids?

Back 246

30 sec - 1 minute or so

Front 247

if you apply lidocaine to a cat's arytenoids and after about 2 minutes, you are still getting laryngospasm, what are two things you can do other than applying more lidocaine to help intubation?

Back 247

1. use a stylet
2. use more induction drug

Front 248

normal parameters of feline inter-operative anesthesia:
- HR
- RR
- eye position
- BP

Back 248

- HR: 120-160 bpm
- RR 10-20 bpm
- eye: ventro-medial
- BP: same as other mammals

Front 249

what are three potential complications during feline general anesthesia?

Back 249

1. hypothermia - small or skinny patients
2. hypotension - very sensitive to volume overload, so watch your drip rate
3. bronchoconstriction - underlying asthma, reactive airway

Front 250

how can you tell if a cat may be having bronchoconstriction during general anesthesia?

Back 250

squeeze the reservoir bag; if bronchoconstriction, the bag may be stiff

Front 251

what are three complications of feline general anesthesia during the recovery phase?

Back 251

1. HYPERthermia - "cats get hot"; young healthy animals
2. HYPOthermia: common; warming PRN (don't use a heat lamp)
3. slow recovery - delayed metabolism? Reversal?

Front 252

what comprise a "kitty bomb" or "kitty magic"?

Back 252

ketamine, dexmedetomidine, opiod (e.g. butorphanol or buprenorphine)

Front 253

what are three sedation protocols for feline general anesthesia?

Back 253

1. "kitty bomb": ketamine, dexmedetomidine, opiod
2. acepromazine + opiod (slow - 20 minutes)
3. ketamine + midazolam ± opiod (not common; 5 minutes)

Front 254

what are three injectable induction protocols for feline general anesthesia?

Back 254

1. propofol
2. diazepam + ketamine
3. Telazol