test 1 Flashcards
1
Q
what are six considerations that are crucial before anesthetic procedures?
A
- minimum patient database
- proper patient fasting
- pre-induction patient care
- supplies available
- equipment working
- pre-anesthetic medication
2
Q
before the patient comes in for surgery, what 3 things do you need to ensure?
A
- full history has been collected
- patient fasted
- proper documentation completed
3
Q
what is the purpose of the minimum patient database?
A
to make patient care decisions and uncover potential anesthetic risks
4
Q
what does the minimum patient database include?
A
- patient history (incl. signalment
- complete PE findings
- results of preanesthetic diagnostic workup
5
Q
when should the minimum patient database be completed? why?
A
the patient should be scheduled for an appointment several days before the planned procedure; if problems come up they can be addressed prior to surgery
6
Q
why is it important to verbally confirm the scheduled procedure before beginning?
A
can prevent tragic accidents; anesthetizing the wrong patient, performing an unnecessary procedure, not performing a required procedure
7
Q
as a technician, what do you need to obtain from the client regarding patient history?
A
- signalment
- current/past illnesses
- current medications
- allergies and/or drug reactions
- status of preventative care (vaccines, S/N, etc.)
8
Q
why is the signalment so important to know before performing an anesthetic procedure?
A
there are unique species reactions and sensitivities to anesthetic agents
9
Q
t/f - horses and cats are not sensitive to opioids
A
false - they ARE sensitive to opioids
10
Q
t/f - cats produce excess airway secretions under anesthesia
A
true
11
Q
what drug produces sensitivity in boxers and giant breeds?
A
acepromazine
12
Q
what dog breed is resistant acepromazine?
A
terriers
13
Q
what specific type of horse should you not administer acepromazine to?
A
contraindicated for use in stallions
14
Q
xylazine is contraindicated for use in pregnant ___ and ___ ?
A
cows and ewes
15
Q
what unique response can be seen in cats after administration of ketamine?
A
prolonged recovery
16
Q
what might happen to a dog after being sedated with acepromazine?
A
may see behavioural changes
17
Q
what details of past/current illnesses should be acquired with patient hx?
A
- preexisting disease
- changes in behaviour
- exercise intolerance
- weakness
- fainting and/or seizures
- unexplained bleeding
18
Q
why would it be important to use a consistent technique when doing physical assessments?
A
to avoid missing any areas of the body - need to examine the entire patient
19
Q
what four factors of patient appearance should be assessed?
A
- symmetry
- mentation
- posture/gait
- hydration status
20
Q
t/f - patient dose is based on lean body weight
A
true
21
Q
how can you assess the hydration status of a patient?
A
- skin turgor
- placement of eye in orbit
- mucous membrane colour, capp. refill time
- heart rate//pulse strength
22
Q
once the hydration is assessed, what must be done before anesthesia?
A
must correct any hydration abnormalities
23
Q
when taking TPR values, what is important to observe with patient respiration?
A
what the character of respiration is - how much effort are they exerting to breathe?
24
Q
what exterior surfaces would you assess on PE?
A
- hair coat
- skin
- lymph nodes/mammary glands
- body openings (odours, discharge)
- eyes, ears, nose, throat
25
what is it called when the pupils are normally two different sizes?
anesicoria
26
why would you want to assess the patient's haircoat?
hair loss can be proof of infectious and non-infectious conditions
27
how does thoracic auscultation differ from taking the heart rate?
listens for murmurs, arrhythmias, crackles, wheezes, etc.
28
t/f - thoracic auscultation is performed by an RVT prior to anesthesia
true - h/e the DVM should also perform prior to anesthesia
29
why is it important to listen over each valve of the heart?
there can be turbulence in blood flow through only one valve or multiple, need to assess all for heart murmurs
30
t/f - patient resps are proportional to body size
false - patient resps are inversely proportional to body size - small animal, higher resp rate
31
what is "stertor" ?
brachycephalic noise caused by their elongated/thickened soft palate
32
what is stridor?
brachycephalic laryngeal noise
33
what is dyspnea?
shortness of breath
34
what is cyanosis?
blueish colour to mucous membranes
35
what do crackles indicate? (in lung sounds)
moisture in the airways
36
how many quadrants need to be examined when ascultating the lungs?
four
37
what preanesthetic diagnostic tests/procedures need to be completed?
1. CBC
2. urinalysis
3. blood chemistry
4. blood coagulation screens
5. electrocardiogram (ECG)
6. radiography
38
how do you determine the physical status classification of a patient?
based on evaluation of the MPD
39
what does the physical status classification represent?
rates patient anesthetic risk
40
what are the levels of patient risk and what do they represent?
```
PS1 - minimal risk
PS2 - low risk
PS3 - moderate risk
PS4 - high risk
PS5 - extreme risk
```
41
define anesthesia
loss of sensation; one extreme in a continuum level of CNS depression
42
define general anesthesia
reversible state of unconsciousness, imobility, muscle relaxation and loss of sensation
43
define surgical anesthesia
analgesia and muscle relaxation; eliminates pain and patient movement
44
define local anesthesia
targets a small, specific area of the body; drug is infiltrated into desired area to cause loss of sensation
45
define topical anesthesia
applied to body surface or wound; produces a superficial loss of sensation
46
define regional anesthesia
loss of sensation to a limited area of the body; examples are nerve blocks and epidural anesthesia
47
what is balanced anesthesia?
using multiple drugs in smaller quantities for anesthesia
48
what are the two main advantages to balanced anesthesia?
1. maximizes benefits of drugs
| 2. minimizes adverse effects
49
what is an RVT's role as an anesthetist?
1. prep/operate/maintain anesthetic machine
2. administer anesthetic agents
3. perform endotracheal intubation
4. patient monitoring
50
what are some challenges and risks associated with anesthesia?
1. dose calculation and rate adjustment
2. vital signs and anesthetic depth
3. assessing multiple pieces of information
4. patient management
5. accidents
51
why is it so crucial to monitor the patient's cariovascular and pulmonary systems during anesthesia?
drugs may cause changes in the systems which can in turn be lethal
52
what is an endotracheal tube and what does it do?
flexible tube placed in the trachea; delivers anesthetic gases directly from the machine to the lungs
53
what are some advantages of using an endotracheal tube?
1. opens airway
2. less anatomical dead space
3. precision administration of anesthetic agent
4. prevents aspiration
5. responds to respiratory emergencies
6. monitors respirations
54
what are some different kinds of ET tubes?
1. murphy tubes - beveled end and side holes; possible cuff
| 2. cole tubes - no side hole or cuff; used in birds and reptiles
55
why would a polyvinyl chloride ET tube be preferable over a red rubber?
the polyvinyl are clear and stiffer where the red rubber may kink or collapse in the patient
56
why would silicone ET tubes be a good choice?
it is pliable, strong, less irritating and resists collapse
57
how and why are tube cuffs used?
high volume/low pressure; used for short term intubation - pressure is distributed evenly along the cuff length
low volume/high pressure; potential tissue damage
58
why are cuffless tubes on non-inflated cuffs used?
used in small animals to reduce the risk of tracheal damage
59
what is a laryngoscope?
a tool used to increase visibility of the larynx while placing an ET tube
60
t/f - the same laryngoscope can be used for both small and large animals
false - small animals use 0-5 inch blade; large animals use up to an 18 inch blade
61
what does a subglottic airway device do?
allows airway management without invading the tracheal lumen
62
what are some advantages to a SAD?
1. decrease in laryngospasm
2. resistance to breathing
3. decreased risk of airway trauma
4. no post-op coughing
63
t/f - masks are used to administer oxygen and anesthetic gases to intubated patients
false - masks are used when the patient is not intubated
64
what are the four components of the anesthetic machine?
1. compressed gas supply
2. anesthetic vaporizer
3. breathing circuit
4. scavenging system
65
what oxygen level is required to maintain cellular metabolism under anesthesia?
30% oxygen
66
what purpose does the compressed gas supply (oxygen) serve?
used to increase inspired air to at least 30% O2
| used to carry vaporizedd anesthetic to patient
67
what is the difference between E tanks and H tanks?
E tanks - small, attached directly to anesthetic machine
| H tanks - large, attached remotely to anesthetic machine
68
where is the control valve located?
on top of the tank
69
what is the control valve used for?
an outlet port; can be loosened or tightened
70
what does the pressure reducing valve do?
reduces outgoing pressure to a usable level
71
when should the primary and secondary oxygen supplies be checked?
at the beginning and ending of every day
72
t/f - the compressed gas valve is turned counter clockwise to open
true
73
what happens when the valve stem is turned completely clockwise?
gas flow stops
74
how do you release line pressure?
depress the O2 flush valve or open the valve until all gas is vented
75
what are some safety issues associated with compressed gas?
1. combustability
2. yoke attachment
3. high-pressure release
4. storage
5. colour coding (knowledge)
76
what colour are oxygen cylinders in canada?
white
77
what kind of gas is contained within a blue cylinder?
nitrous oxide
78
what is the tank pressure gauge used for?
to indicate the pressure of gas remaining in the cylinder; determines the number of liters remaining in a tank
79
what does the pressure-reducing valve do?
reduces gas pressure to a constant 40-50 psi
80
what is another name for the pressure-reducing valve?
pressure regulator
81
what does the line pressure gauge do?
indicates pressure in the gas line between the pressure-reducing valve and the flowmeter
82
what should the line pressure gauge read when the oxygen tank is opened?
40-50 psi
83
what must you do after turning the tank off?
evacuate line pressure until the gauge reads 0 psi using the oxygen flush valve
84
what does the flowmeter do?
1. indicates gas flow expressed in liters per minute (L/min)
2. reduces pressure of gas to 15 psi
85
who controls the flow rate during anesthetic procedures?
the anesthetist (RVT)
86
what is the purpose of the oxygen flush valve?
1. delivers a short, large burst of pure oxygen directly into the rebreathing circuit or common gas outlet
2. bypasses vaporizer and flowmeter
3. used to refill breathing bag or to dilute anesthetic gas remaining in circuit at the end of anesthesia
87
when should you NEVER use the oxygen flush valve?
when the patient is hooked up to the breathing circuit
88
what does the anesthetic vaporizer do?
converts liquid anesthetic agent to a gaseous state; adds a controlled amount of vaporized agent to the carrier gas
89
how does the gas mixture leave the vaporizer?
through the outlet port
90
what is fresh gas?
mixture of vaporized anesthetic agent and carrier gas that enters the breathing circuit
91
how does the carrier gas (oxygen) get into the vaporizer to create fresh gas?
vaporizer inlet port; the oxygen exits the flowmeter into the inlet port
92
what are the different kinds of anesthetic vaporizers?
1. non-precision
| 2. precision
93
t/f - non-precision vaporizers are safer, and used more often than precision
false - non-precision vaporizers deliver low pressure vapor based on estimation
94
how are precision vaporizers used?
deliver a precise amount of anesthetic to the patient; high vapor pressure that is controlled by the anesthetist
95
what factors affect vaporizer output?
1. vaporizer setting
2. carrier gas flow
3. temperature (most modern vaporizers are compensated)
96
what color indicates isoflurane vaporizer?
purple
97
what colour indicated sevoflurane vaporizer?
yellow
98
what are the induction and maintenance rates of isoflurane and sevoflurane?
isoflurane - 3-5% induction; 1.5-2.5% maintenance
| sevoflurane - 4-6% induction; 2-4.5% maintenance
99
what do you do to turn on the vaporizer?
1. depress safety lock
| 2. turn dial to desired level (measured in percent concentration)
100
how full should the vaporizer be kept? what can happen if the level is incorrect?
should be at least half-full; if over full can result in overdose, if underfull can cause difficulty to keep patient anesthetized
101
what happens at hte vaporizer outlet port?
1. oxygen/anesthetic exits vaporizer
| 2. connected to the common gas outlet or directly into breathing circuit
102
what happens at the common gas outlet?
fresh gas outlet; connected to the vaporizer outlet port and breathing circuit
103
what does the breathing circuit do?
1. carries anesthetic and oxygen from the fresh gas inlet to the patient
2. conveys expired gases away from the patient
104
what are the two types of breathing circuits?
1. rebreathing
| 2. non rebreathing
105
how does a rebreathing system work?
1. circle system
2. not used on very small animals
3. carbon dioxed is removed from exhaled air (in canister)
4. exhaled air is inhaled again with added oxygen and anesthetic
106
how does air flow through a rebreathing system?
1. inhalation unidirectional valve
2. inhalation tube
3. animal
4. exhalation tube
5. exhalation unidirectional valve
6. carbon dioxide absorber canister
7. past reservoir bag
8. pop-off valve
9. pressure manometer
10. inhalation unidirectional valve
107
how is a closed rebreathing system different from a semi-closed rebreathing system?
closed is a total system; pop-off valve is nearly or completely closed; oxygen flow is low - used mostly for large animal
108
how is a semi-closed rebreathing system different from a closed rebreathing system?
partial system; pop-off valve is open and oxygen flow is high - excess air is released into scavenging system
109
t/f - it is rare to come across semi-closed rebreathing system in modern practice
false - semi-closed rebreathing is the most common configuration
110
what are the parts that compose a rebreathing system?
1. fresh gas inlet
2. unidirectional valves
3. reservoir bag
4. pop-off valve (pressure relief)
5. carbon dioxide absorber canister
6. pressure manometer
7. air intake valve
8. corrugated breathing tubes
9. y-piece
111
what do unidirectional valves do?
1. control the direction of gas flow (inspiratory, expiratory)
2. open and close as patient breathes
3. monitor respiratory rate and depth
4. monitor for sticking due to condensation
112
what does the pop-off valve allow for?
1. excess carrier and/or anesthetic gases to exit the breathing circuit and enter the scavenging system
2. prevents excessive pressure or gas volume in the circuit
113
what position should the pop-off valve be in when manually ventilating a patient?
closed
114
what does the reservoir bag do?
1. provides a flexible air storage reservoir
2. indicates respiratory rate and depth
3. confirms proper endotracheal tube placement
115
t/f - the reservoir bag can deliver anesthetic gases or pure oxygen to the patient
true
116
why would you manually ventilate a patient?
to force fresh gas into alveoli to normalize gas exchange; this normalizes the respiratory rate
117
t/f - manual ventilation minimizes atelectasis
true
118
how often should you ventilate the patient when bagging them?
every 5-10 minutes
119
what is contained within the carbon dioxide absorber canister? what happens when carbon dioxide is absorbed?
contains absorbent granules (calcium hydroxide) - granules react with carbon dioxide to form calcium carbonate
120
what should the capnograph read if the cannister is expired?
anything greater than zero indicates an expired cannister
121
what does the pressure manometer do?
indicates the pressure of gases within the breathing circuit
122
what unit does the pressure manometer express?
centimeters of water
123
how many centimeters of water are used when ventilating small and large animals, respectively?
small animals - 20 cm H2O
| large animals - 40 cm H2O
124
what does the pressure manometer do when bagging a patient?
prevents excessive pressure in the lungs
125
what does the air intake valve do?
aka negative pressure relief valve - admits room air into the circuit if negative pressure is detected in the breathing circuit
126
what is a sure sign of negative pressure in the circuit?
collapsed reservoir bag
127
what will the patient develop if negative pressure enters the circuit ?
hypoxemia
128
t/f - negative pressure is sometimes okay when performing anesthesia
false - we NEVER want negative pressure
129
how many sizes do breathing tubes come in? what are they?
three; 50mm, 22mm and 15mm
130
what does the breathing tube connect to?
unidirectional valve and y-piece
131
what size patient requires a non-rebreathing system?
<7 kg
132
how does a semi-open system work?
exhaled gas is evacuated by the scavenging system, fresh gas is routed to the patient directly from the vaporizer - no carbon dioxide absorber canister, pressure manometer or unidirectional valves
133
components of a semi-open non-rebreathing sytstem?
endotracheal tube connector, fresh gas inlet, reservoir bag, overflow valve, scavenger tube and scavenger system
134
what are the two main configurations of non-rebreathing circuits?
1. bain coaxial circuit
| 2. ayres t-piece
135
what is the benefit of a coaxial circuit?
exhaled gas comes through the outside tube - this warms the inhaled air slightly
136
what is the animal's dead space?
the space from the mouth down to the lungs
137
what is considered the machine's dead space?
all the way through the animal to the inspired gas
138
what is the danger with resistance?
any increased resistance to inspiration or expiration will cause an anaesthetized animal to breathe less effectively
139
what causes resistance on inspiration?
1. gas level too low
| 2. tube is kinked
140
what causes resistance on expiration?
1. kink in the tube
2. wrong bag
3. pop off isn't open
4. natural resistance through canister
141
t/f - smaller diameter greatly increases resistance
true
142
what is circuit drag?
the weight of hoses, machinery, etc. can cause the endotracheal tube to come out of the patient
143
t/f - when choosing an endotracheal tube you want to pick the smallest option
false - you want to place the largest tube possible without causing trauma
144
how do you calculate bag size?
tidal volume x 6
| tidal volume - 10-20ml/kg
145
do non-rebreathing systems require high or low flow rates?
high flow rates based on patient body weight
146
calculate flow rate ?
200-300 ml/kg/min
147
what is the minimum flow rate?
500 ml/min
148
define an anesthetic agent
any drug used to induce a loss of sensation with or without unconsciousness
149
define adjunct
a drug that is not a true anesthetic but that is used during anesthesia to produce other desired effects such as sedation, muscle relaxation, analgesia, reversal, neuromuscular blockade or parasympathetic blockade
150
t/f - inhalants are the first drugs given during anesthetic procedures
false - inhalants are the last drugs administered
151
what happens if inhalants are used on their own?
patient recovery will be stormy, no pain control
152
what are some examples of inhalant anesthetics?
1. isoflurane, sevoflurane and desflurane
2. nitrous oxide
3. halothane
4. diethyl ether
153
is diethyl ether still used in anesthetic procedures?
no
154
t/f - halogenated organic compounds (like isoflurane) are stored as vapor at room temperature?
false - they are liquid at room temperature and vaporized in oxygen that flows through
155
what are some adverse effects of halogenated organic compounds?
1. increased intracranial pressure (head trauma/brain tumors)
2. hypothermia
3. decreased blood pressure
4. hypoventilation (dose dependent)
5. carbon dioxide retention/respiratory acidosis
156
what are some important properties to consider with inhalant anesthetics?
1. vapor pressure
2. partition coefficient
3. minimum alveolar concentration
4. rubber solubility
157
what is vapor pressure?
the tendency of an inhalation anesthetic to vaporize to its gaseous state; how readily an inhalation anesthetic will evaporate in the anesthetic machine vaporizer
158
t/f - volatile agents require high pressure
true
159
what are some examples of volatile agents?
1. isoflurane
2. sevoflurane
3. desflurane
160
t/f - volatile agents are delivered from a non-precision vaporizer
false - volatile agents are delivered from precision vaporizers only
161
what kind of vapor pressure is required for non-volatile agents?
low vapor pressure
162
what is the blood-gas partition coefficient?
the measure of solubility of an inhalation anesthetic in blood compared to air (alveolar gas)
163
what does the blood-gas partition coefficient indicate?
the speed of induction and recovery
164
t/f - a low blood-gas partition coefficient means a slower expected induction and recovery
false - low blood-gas is indicative for faster expected induction and recovery
165
is it more desirable to have a low blood-gas partition coefficient or a high blood-gas? why?
it is more desirable to have low blood-gas becuase the agent is more soluble in alveolar gas than blood - this means more drug is inhaled and less is absorbed by blood and tissues
166
why might a high blood-gas coefficient cause a slower induction and recovery?
because the drug is more soluble in the blood than alveolar gas, it takes longer for the patient to receive drug because more is being absorbed into the tissues
167
how does a low solubility coefficient work?
inhalant builds up to high concentrations in the pulmonary alveoli - steep diffusion gradient between alveoli and tissues - this causes a rapid entry into blood stream and passage into the brain - rapid induction and recovery
168
t/f - low solubility coefficient inhalants have a long time interval to change anesthetic depth
false - they have a short time interval to change anesthetic depth
169
what is an example of a low solubility coefficient inhalant?
isoflurane
170
why are high solubility coefficient inhalants less effective than low?
inhalant builds up quickly in blood and tissues but is widespread with less concentration in the brain
171
what does MAC stand for ?
minimum alveolar concentration
172
what is the MAC used for?
to measure a drug's potency - used to determine the average setting on the vaporizer to produce anesthesia
173
t/f - a lower MAC would indicate a less potent agent and lower vaporizer setting
false - a lower MAC is indicative of a more potent agent (and lower vaporizer setting)
174
what two species is isoflurane approved for use in?
dogs and horses
175
what are the physical and chemical properties to be aware of for isoflurane?
1. high vapor pressure; precision vaporizer
2. low blood-gas PC; rapid induction/recovery
3. MAC 1.3-1.63%
4. low rubber solubility
5. stable at room temp
6. fewest adverse cardiovascular effects
7. depresses respiratory system
8. maintains cerebral bloodflow
9. almost completely eliminated through the lungs
10. induces adequate muscle relaxation
176
what might isoflurane producde if exposed to desiccate carbon dioxide absorbent?
carbon monoxide
177
what properties should be considered for sevoflurane?
1. high vapor pressure; precision vaporizer
2. low blood-gas
3. high controllability of depth of anesthesia
4. MAC 2.34-2.58%
178
how are anesthetic agents and adjuncts classified?
1. route of administration
| 2. time of administration
179
what are agonists?
most anesthetic drugs; bind to and stimulate target tissue
180
what are antagonists?
reversal agents; bind to target tissue but don't stimulate
181
how are opioids different than agonists or antagonists?
they can be partial agonists, agonist-antagonists and can block pure agonists
182
t/f - if a drug combination develops a precipitate when mixed in a syringe you can still administer it
false - never administer a drug if a precipitate forms
183
t/f - you can mix drugs in a single syringe if they are compatible
true
184
what drug can only ever be mixed with ketamine?
diazepam - it is not compatible with any other drug available
185
is diazepam water soluble?
no
186
is midazolam water soluble?
yes
187
what is the purpose of preanesthetic medications?
1. calm or sedate excited animal
2. minimize adverse drug effects
3. reduce dose of concurrent drugs
4. smoother induction and recovery
5. analgesia
6. muscle relaxation
188
what are preanesthetic anticholinergics?
parasympatholytic drugs - they work against the parasympathetic system to prevent and treat bradycardia - increases heartrate and decreases secretions
189
what do parasympatholytic drugs block?
acetylcholine
190
what are two examples of preanesthetic anticholinergics?
1. atropine
| 2. glycopyrrolate
191
when might atropine be used?
when animal is arresting
192
what are some adverse effects of anticholinergics?
1. cardiac arrhythmia
2. temporary bradycardia
3. thickened respiratory and salivary secretions
4. intestinal peristalsis inhibition
193
what kinds of drugs fall under tranquilizers and sedatives?
1. phenothiazines
2. benzodiazepines
3. alpha 2-adrenoceptor agonists
4. alpha 2-antagonists
194
what species are approved for use of acepromazine?
horses, dogs and cats
195
what family of drug is acepromazine related to>
phenothiazines
196
t/f - acepromazine has a reversal agent
false
197
where is acepromazine metabolized? what patients might this be a concern for?
metabolized by liver; contraindicated for use in patients with liver disease
198
what is the half life of acepromazine in canines?
4.5 hrs
199
how does acepromazine effect the body?
1. calming effect on CNS ; decreased interest in surroundings
2. protects cardiovascular system against arrhythmias and decreases cardiac output
3. mild antiemetic effects
200
what are some adverse effects of acepromazine?
1. may produce aggression or excitement
2. peripheral vasodilation (hypotension, increased heart rate, hypothermia)
3. penile prolapse (horses)
201
what special consideration is given to drugs ending in -epam?
these are controlled drugs
202
what reversal agent is used for benzodiazepines?
flumazenil (limited availability)
203
t/f - benzodiazepines have a rapid onset of action
true
204
do all benzodiazpenes have the same duration of action?
no - duration varies with drug
205
what receptors do benzodiazepines act on?
gaba receptors
206
what are some effects of benzodiazepines?
calming and anti-anxiety, anticonvulsant
207
adverse effects of benzodiazepines?
1. disorientation and excitement (young dogs) 2. dysphoria and aggression (cats)
208
t/f - diazepam can be given by rapid IV
false - diazepam must be given by IV slowly !
209
what can happen if cats are given oral diazepam?
fatal liver necrosis
210
what drug is commonly administered with diazepam to induce anesthesia in small animals?
ketamine
211
what makes midazolam unique from diazepam?
it is water soluble
212
does diazepam or midazolam have a shorter half life?
midazolam - 1 hr (vs. diazepam - 3 hrs)
213
are alpha 2 agonists controlled agents?
no; they are non-controlled
214
what effects do alpha 2 agonists produce?
1. sedation
2. analgesia
3. muscle relaxation
215
what agents readily reverse alpha 2 agonists?
alpha 2 antagonists
216
what are some examples of alpha 2 agonists?
1. xylazine
2. dexmedetomidine (dexdomitor)
3. detomidine (dormosedan)
4. romifidine (sedivet)
217
how do alpha 2 agonists act on the body?
take away fight or flight response by decreasing the release of norepinephrine
218
where are alpha 2 agonists metabolized? excreted?
the liver; urine
219
do alpha 2 agonists cause rapid or slow sedation?
rapid; duration depends on species and drug of choice
220
how do alpha 2 agonists effect the cardiovascular system? (early phase)
1. vasoconstriction and hypertension
2. bradycardia
3. arrhythmias
221
how do alpha 2 agonists effect the cardiovascular system? (late phase)
1. decreased cardiac output
| 2. hypotension
222
t/f - alpha 2's cause an immediate vomiting response in dogs and cats
true
223
what are some adverse effects of alpha 2's ?
1. change in behviour
2. increased myocardial O2 consumption
3. decreased cardiac output
4. increased systemic vascular resistence
5. respiratory depression
6. increased urination
7. bloat
8. premature parturition (cattle)
9. absorbed through skin abrasions and MM
10. sweating (horses)
224
what patients should alpha 2's be avoided in?
geriatric, diabetic, pregnant, pediatric or ill
225
t/f - dexdomitor (dexmedetomidine) is safer and more potent than xylazine
true
226
what antagonist is used to reverse dexmedetomidine?
atipamazole (antisedan)
227
can dexdomitor be safely combined with other drugs?
yes
228
what combination is commonly referred to as "kitty magic"?
1. ketamine
2. opioid (hydromorphone or butorphanol)
3. dexdomitor
229
what species do we use detomidine in?
horses
230
is detomidine longer or shorter acting than xylazine?
longer - 2x duration
231
what is important to remember if administering an alpha 2 antagonist?
they reverse ALL effects of alpha 2 agonists - beneficial and detrimental
232
when should the dose of antagonist be reduced?
if more than 30 minutes has passed since administering the agonist
233
what is yohimbine used to reverse?
xylazine
234
how long does it take to see the effects of atipamezole (antisedan) after administration?
5-10 minutes
235
what are some commonly used opioids? what are their classifications?
1. agonists
- morphine
- hydromorphone
- oxymorphone
- fentanyl
- meperidine
2. partial agonist
- buprenorphine
3. agonist-antagonists
- butorphanol
- nalbuphine
4. antagonists
- naloxone
- etorphine
- carfentenil
236
t/f - opioids do not have a wide margin of safety
false - they do have a wide margin of safety
237
where do opioids act on the body?
on mu, kappa and delta receptors; action on the receptors and spinal cord
238
what type of opioids act on mu and kappa receptors?
agonists
239
what level of pain is ideal for agonists?
moderate to severe pain
240
agonist-antagonists bind to mu and kappa receptors but only stimulate one - which is it?
agonist-antagonists stimulate kappa receptors
241
what effects do opioids cause in dogs?
1. sedation
| 2. narcosis
242
what is narcosis?
narcotic-induced sleep
243
what effects do opioids have on cats/horses/ruminants?
1. CNS stimulation
| 2. bizarre behaviour/dysphoria
244
what specific type of agonists are most effective against severe pain?
pure agonists
245
opioids can effect the pupils of dogs, cats and horses - what are their respective effects?
dogs - miosis (small pupils)
| cats/horses - mydriasis (large pupils)
246
t/f - opioids can cause dogs to become hyperthermic
false - can cause dogs to become hypothermic
247
do opioids cause temperature changes in cats?
yes - can cause hyperthermia in cats
248
t/f - opioids cause increased urine production
false - cause decreased urine production
249
what are some adverse effects of opioids?
1. anxiety/disorientation/dysphoria
2. bradycardia
3. decreased respiration
4. ceiling effect (some agents)
5. salivation and vomiting
250
what is the biggest respiratory concern with opioids?
respiratory suppression
251
t/f - intraocular and intracranial pressure are increased under opioids
true
252
define neuroleptanalgesia
use of a sedative and an opioid
253
what 2 uses do opioids have in surgical procedures?
1. preanesthetic meds
| 2. analgesia
254
why is it important to know the half life of a drug you are reversing with naloxone hydrochloride?
if the half life of the drug you reversed is longer than the duration of action, you may see patient go down again depending on how much drug has been metabolized in their system
255
how long is the duration of action for naloxone?
30-60 minutes
256
what are some indicatiosn for use of trazodone?
1. anxiety patients
2. pre-op to reduce stress
3. post-op to allow better recovery
257
what is the mode of action for trazadone?
serotonin antagonist; blocks serotonin reuptake at presynaptic neuorn
258
what unique situation may cause us to see aggression in patients once they are put on this medication?
if aggression has been suppressed due to fear - now the animal is at ease and the aggression can come out
259
why would trazodone be used with other behaviour meds?
it has a faster onset of action while waiting for other medications to start working (4-6 weeks)
260
what are the indications for use of gabapentin?
used for its analgesic and anxiolytic qualities
261
what is unique about gabapentin as an analgesic?
it works at the nerve level to relieve neurogenic pain
262
what can gabapentin be combined with to control patient pain?
gabapentin and an NSAID
263
what is the generic name for Cerenia?
maropitant
264
what are the indications for use of cerenia?
anti-emetic; prevents vomiting from premedication, helps patients eat faster post-op
265
t/f - cerenia has some effect on visceral pain
true
266
what does the acronym PISS stand for ?
pin index safety system
267
what does the acronym DISS stand for?
diameter index safety system
268
t/f - when giving injectable anesthetics we give the full dose in the syringe
false - iv anesthetics are administered "to effect"
269
t/f - injectable anesthetics can be used on their own to produce general anesthesia
false - must be used with other agents to produce complete effects of GA
270
what is propofol?
ultra short acting, non-barbituate anesthetic
271
what is propofol used for?
1. induction
| 2. short term maintenance
272
what special exception is made for propofol IV ?
the solution is milky but it is okay to administer (it is fat soluble)
273
how long is the onset of action for propofol?
30-60 seconds
274
how long is the duration of action of propofol?
5-10 minutes
275
how does a patient's plasma protein level effect administration of propofol? why?
propofol binds to protein so if plasma protein is low there will be more drug free-flowing and potency will be higher
276
t/f - propofol is rapidly removed from the brain by tissue redistribution
true
277
how does bloodflow affect the action of propofol on the body?
after iv administration the highest areas of blood flow will receive the most drug; this happens through tissue redistribution
278
how does propofol effect the CNS ?
1. dose-dependent depression (sedation-GA)
2. transient excitement/muscle tremors
3. seizure-like signs
279
how does propofol effect the cardiovascular system?
1. depressant
| 2. transient hypotension
280
how does propofol effect the respiratory system?
1. possible apnea (post induction)
281
why do you need to ensure the patient is breathing in gas post-induction? (propofol)
if they are not breathing in gas, they can wake up within 5 minutes
282
what may happen if propofol is administered too slowly?
may cause excitement in the patient
283
how can you reduce the risk of apnea when using propofol?
use with another pre-medication (lower dose)
284
how long does it take for dogs and cats to fully recover from the effects of propofol?
dogs - 20 minutes
| cats - 30 minutes
285
what are some general characteristics of alfaxalone?
1. short duration of action
2. wide margin of safety
3. use IV for induction and maintenance
4. use IM in cats for deep sedation/light anesthesia
286
what are some effects of alfaxalone?
1. dose-dependent CNS depression
2. can cause apnea
3. hypotension
287
what are some risks associated with alfaxalone?
1. patient can easily wake up
| 2. can cause hypoxia
288
t/f - alfaxalone does not require intubation
false - intubation is necesary
289
how long does alfaxalone last in dogs and cats?
dogs - 10-15 minutes
| cats - 15-20 minutes
290
is it safe to combine alfaxalone with other injectable anesthetics?
no
291
what is the most commonly used barbituate?
thiopental (pentothal)
292
what are the characteristics of thiopental?
1. high lipid solubility
| 2. rapid anesthetic effect, rapid recovery
293
how are the effects of thiopental terminated?
through redistribution of drug into body fat
294
what are some risks associated with thiopental?
1. splenic enlargement
2. avoided in sighthounds
3. very rarely used
295
what are 2 examples of dissociative anesthetics?
1. ketamine
| 2. tiletamine
296
t/f - dissociative anesthetics are used with other drugs to induce general anesthesia
true
297
are dissociatives controlled?
yes
298
t/f - dissociatives have no pain control
false - have good pain control at low doses
299
what does an animal look like when under dissociative anesthesia?
trancelike state; animal appears awake but is immobile and unaware of surroundings
300
t/f - dissociative anesthetics decrease windup through NMDA inhibition
true
301
are the patient's reflexes intact when under dissociative anesthesia?
yes
302
how do dissociatives effect the cardiovascular system?
increased heart rate, cardiac output, and blood pressure
303
what is apneustic respiration? when might we see it?
animal inhales, looks like they hold their breath and then they exhale ; might see at higher doses of dissociatives
304
adverse effects of dissociatives?
increased intracranial and intraocular pressure
305
t/f - there is one effective reversal agent for dissociative drugs
false - there is no effective reversal agent
306
when does IV ketamine reach it's peak action?
1-2 minutes after injection
307
when does IM ketamine reach it's peak action?
10 minutes after injection
308
what is ketamine's duration of effect?
20-30 minutes; increasing the dose will prolong duration but will not increase the anesthetic effect
309
KetVal is the trade name for what drug combination?
ketamine and valium (diazepam)
310
what is KetVal used for?
IV induction
311
t/f - KetVal has a rapid onset of action
true - 30-90 seconds
312
how long is the duration of action of ketval?
5-10minutes
313
how long does it take for patients to recovery after being under ketval?
30-60 seconds
314
what are some advantages to the ketamine diazepam combination?
1. minimal cardiac depression
2. good muscle relaxation
3. superior recovery
4. some analgesia
315
what are some disadvantages to ketamine/diazepam combination?
1. possibility of respiratory depression is greater in combination
2. cannot use IM (midazolam can be used in place)
316
what three drugs compose "kitty magic" ?
1. dexdomitor
2. ketamine
3. opioid
317
how can you easily reverse the effects of dexdomitor?
administer a half of dose of antisedan
318
what is guaifenesin?
a non-controlled muscle relaxant
319
t/f - guaifenesin is an anesthetic drug
false - it is neither anesthetic or analgesic
320
at what point of the anesthetic procedure is guaifenesin used? what other drug is it combined with?
used with ketamine during induction protocol
321
t/f - guaifenesin is administered with a slow IV drip
false - administered rapidly IV until animal is ataxic
322
what species do we use guaifenesin for?
horses
323
what risks are involved if guaifenesin is used without premedication?
1. may cause excitement
| 2. increased risk of side effects
324
can guaifenesin be used as a sole agent?
no; the sedation/analgesia are inadequate for surgery
325
what are the adverse effects of propofol? how can you prevent it?
1. apnea
2. bradycardia
3. hypovolemia
minimize risk by titrating to effect
326
how many ET tubes should you set out to prepare for intubation? how do you pick?
3 tubes; one based on weight, one a half size smaller, one a half size larger
327
what position must your patient always be in for intubation?
sternal recumbency
328
t/f - it is best practice to preoxygenate for 3 minutes prior to intubation
true - especially for brachycephalic breeds
329
what should you always assess before intubating your patient?
depth of anesthesia
330
what do you need to be cautious of when intubating a cat?
largynospasm - can be avoided by using a local anesthetic
331
what is the opening called where you insert the endotracheal tube?
glottal opening
332
t/f - the endotracheal tube should be advanced on expiration
false - should be advanced on inspiration
333
how should you react to a patient coughing or resisting on intubation?
stop immediately and administer more induction agent
334
how can you confirm the placement of the ET tube?
1. look for condensation in the tube
2. watch reservoir bag for movement
3. palpation of neck
335
how do you inflate the cuff?
use a syringe with 0.5ml increments until no leak is heard when reservoir bag is squeezed and pressure in the breathing circuit is 15cm H2O
