Exam I - Anesthetics Flashcards
1
Q
What is the function of the thalamic circuit?
A
-sensory processing
-attention
2
Q
What is the function of the thalamocortical circuit?
A
-conciousness
-awareness
3
Q
What is the function of the hippocampal network?
A
-memory
4
Q
________ Receptors & ________ receptors also mediate fast excitatory impulses but have little anesthetic sensitivity
A
-AMPA
-Kainate
5
Q
What 2 neurotransmitters bind to NMDA receptors?
A
-Glutamate
-Glycine
6
Q
What gas effects the NMDA receptor?
A
N2O
7
Q
Although the NMDA is a _______-gated ion channel, it is also sensitve to the _______ across the membrane containing the receptor
A
-Ligand-gated
-voltage
8
Q
_______ blocks the ion channel on the NMDA receptor until membrane depolarization occurs
A
-Mg2+
9
Q
(t/f) NMDA receptors must be activated before they can be antagonized
A
True
*Ketamine binding site is same location as Mg2+ that blocks the ion channel. Have to remove the Mg2+ through activation of the receptor to allow antagonists to bind.
10
Q
What is the only anesthetic than can be used soley for GA that has analgesic properties?
A
Ketamine
*Dexmedetomidine (Precedex) is the only other sedative that has analgesic properties but it can’t be used as sole agent for GA
11
Q
The _____ molecular position on barbituate molecules is responsible for the _______ effect of the drug. __________ sidechains have a greater effect than _________ chains
A
-C5
-hypnotic effect
-Branched sidechains > straight chains
12
Q
What drug has a Phenyl Group @ C5
A
Phenobarbitol
13
Q
What drug has a Methyl Group @ N1
A
Methohexital
14
Q
What drug has a Sulfer atom @ C2
A
-Sodium thiopental
*aka Thiobarbituate
15
Q
__________ was THE intravenous induction agent for anesthesia prior to Diprivan (Propofol).
Production in the U.S. stopped in 2010.
*BLUE BOX
A
Thiopental
16
Q
Most important determinant of awakening
A
Redistribution to inactive, poorly perfused tissues
17
Q
Onset of action of Sodium Thiopental (Pentothal)
A
30-60 sec
18
Q
Onset of action of Methohexital (Brevital)
A
Immediate
*maximal brain uptake in 30 sec
19
Q
The time to achieve a 50% reduction in concentration after stopping a continous infusion
A
Context-sensitive half-time
20
Q
What 2 drugs (maybe 3) are contraindicated in Hypersensitivity/Intermittent
Porphyria?
A
-barbiturates
-etomidate
Nagelhout - includes Benzos (word for word)
21
Q
What 2 drugs cause increased incidence of myoclonus?
A
-Barbiturates (methohexital)
-etomidate
22
Q
What drugs increases frequency of Cl- channel opening via GABAa receptor stimulation
A
Benzos
23
Q
Barbiturates have a _____ context-sensitive half-time
A
Prolonged
24
Q
Barbiturates exhibit ______ order kinetics
A
Zero order
25
Zero order kenetics means what
Drug is eliminated per unit/time
*ex. - 5mg/hr
26
DOA of thiopental
*Red/bolded in PP
5-30 min
27
DOA of methohexital
*Red/bolded in PP
4-7 min
28
Rectal induction dose of methohexital
*Red/bolded in PP
25 mg/kg
29
Sodium thiopental (pentothal) has ___________ effects
*bolded in red on Dr. B's PP chart
anticonvulsant effects
30
Methohexital (brevital) _________ the seizure threshold
Lowers
31
What drug is know for histamine release?
Sodium thiopental (pentothal)
32
What are the 3 MOAs of barbiturates?
-Potentiate GABA
-Block glutamate @ AMPA receptors
-Block neuronal Nicotinic receptors
33
Primary anesthetic use of midazolam (versed) is __________
premedication
34
An induction dose of midazolam (versed) would ________ emergence
Delay emergence
35
Midazolam (versed) causes _________ amnesia
Anterograde
36
_________ increase GABAa affinity for GABA
*only one in Dr. B PP that specifies this
benzos
37
Which subunit of the GABAa receptor do benzos bind to to mediate sedative, amnestic & anticonvulsant effects
a1 subunits
38
Which subunit of the GABAa receptor do benzos bind to to mediate anxiolysis, anti-hyperalgesia, & centrally mediated muscle relaxation
a2 subunits
39
Onset of diazepam (valium) IV
Almost immediate
40
Onset of midazolam (versed) IV
1-5 min
41
DOA of diazepam (valium)
20-30min
42
DOA of midazolam (versed)
2 hrs
43
T 1/2 of diazepam (valium)
30-50 hrs
*"half-life is equal to pt age in years"
44
T 1/2 of midazolam (versed)
1-4 hrs
45
Metabolite of midazolam (versed)
1-hydroxymidazolam
46
Metabolism of diazepam (valium)
Desmethylmedazolam
to
Nordiazepam
to
Oxazepam (active benzo) --> secondary peak 6-12hrs
to
Inactive metabolite
47
Diazepam (valium) interacts (C/I) w/ ___________ & ___________
-erythromycin
-anti-fungals
48
Midazolam (versed) C/I w/ _________ & __________
-pregnancy
-elderly (all benzos)
49
(t/f) benzos are ok for neuro cases
True
50
Benzos _______ the seizure threshold
increase
51
(t/f) benzos do not decrease central respiratory system
False
*midazolam decreases central respiratory system the most
52
What drug reverses benzos
Flumazenil (Romazicon)
53
Is flumazenil (romazicon) a competitive or non-competitive antagonist to benzos
Competitive
54
Flumazenil (romazicon) is chemically similar to benzos except that the phenyl group
is replaced by a _________ group
carboxyl
55
(t/f) DOA of Versed exceeds Romazicon
True
*VERNON PP SAYS ONLY LORAZEPAM IS LONGER THAN FLUMAZENIL
*DR. B SAYS VERSED
*EXPECT NEED FOR RE-DOSING!!
56
Flumazenil (romazicon) is C/I in pt w/ ________ disorders
Seizure disorders
57
________ is the cardiac stable induction agent
Etomidate
58
You give midazolam (versed) to pt in pre-op and you want to run to the restroom real quick before you take the patient to the OR. It will only take a minute. Is this ok?
*BLUE BOX
NO
*DO NOT LEAVE PT UNATENDED AFTER VERSED ADMINISTRATION
59
Etomidate causes _________ ___________ r/t to the suppression of cortisol production due to suppression of a the synthesizing enzyme _____-______________ in the adrenal ________
-Adrenal suppression
-11β-Hydroxylase
-adrenal cortex
60
(t/f) etomidate can cause burst suppression
True
61
(t/f) Etomidate produces just as much respiratory depression as other IV anesthetic agents
False
*less than other agents
62
T 1/2 of flumazenil (romazicon)
Dr. B = 41-79 min (t 1/2)
Dr. V = 45-90 (DOA)
*SHORTER/LONGER THAN VERSED AND/OR LORAZEPAM --> MAY HAVE TO REDOSE!!
63
Regarding flumazenil (romazicon), if you have to give > ____mg dose to reverse the pt, then there is an underlying issue
>0.6mg
64
Midazolam has a _____ ring as its primary structure which makes is H2O soluble and prevents pain on IV injection d/t not having to use preservatives/solvents
Imidazole ring
*iMIDAZOLe = MIDAZOLam
65
_________ ___________ of benzos can prolong duration of benzos in renal failure pts
Active metabolites
66
Etomidate MOA
Dr. B - mimics inhibitory effects of GABA
Dr. Vernon - allosterically binds GABAa & increases affinity for GABA
67
(t/f) high doses of etomidate, >0.3 mg/kg, can cause decreases in BP & CO
True
(even though its considered cardiac stable)
68
Of all of the clinically used IV anesthetics, __________ has the greatest selectivity for GABAA Receptors and has the fewest relevant interactions with other ion channels/receptors.
*BLUE BOX
Etomidate (amidate)
69
The excitatory phenomenon (myoclonus) caused by etomidate can be mitigated by concurent administration of _________ or __________
Opoids or Benzos
70
Etomidate is a potent cerebral ______________
vasoconstrictor
71
Etomidate is not approved for children <____ yrs
Dr. B - <10 yrs
Dr. V - <5 yrs
72
(t/f) etomidate is structurally similar to some other anesthetics
False
*structurally unrelated to other anesthetics
73
Preservative in Diprivan
EDTA
74
Preservatives in Propofol
-sodium metabisulfite (bronchoconstriction in Asthma)
-benzyl alcohol
75
Propofol MOA
Dr. B - GABA mimetic (direct)
Dr. V - Allosterically binds GABAa & increases affinity for GABA
Other sources: (hold no weight on this test)
Low dose = allosteric
High dose = direct
76
Propofol predominantly binds to the ____ subunits of the GABAa receptors
B2 subunits
77
Are there amnestic properties in propofol?
Dr. B - No
Dr. V - Yes
Other sources: ???
78
Egg allergies are C/I w/ propofol
Technically no
79
Egg lecithin/yolk allergies are C/I w/ propofol
Yes
80
The contents of an opened ampule, vial or syringe must be discarded if not used within ___ hours.
*BLUE BOX
6 hrs
81
When preparing a syringe, label appropriately with initials, date and _______
*BLUE BOX
time of expiration
82
Propofol with ____________ preservative increases bronchial tone and does not blunt the _________ mediated effects leading to _____________.
-metabisulfite
-vagally
-bronchoconstriction
83
Sodium metabisulfite – can potentially irritate __________ and/or those allergic to _______ drugs
-asthmatics
-sulfa
84
Mixing lido & propofol: No more than ___mg of Lidocaine with ___mL of Propofol
Starts to separate after ___ hour
Risk of _________ _________ ________
*BLUE BOX
-20mg Lido w/ 20mL prop
-1 hr
-microscopic fat emboli
85
Propofol is a cerebral _____________
vasoconstrictor
*this is how it decreases ICP
86
Primary disatvantage of propofol
Depressive effects on CV effects
87
Caution w/ propofol in pts with critical ______ ________ or __________ ________
-aortic stenosis
-cardiac tamponade
88
Which is faster onset & offset. Ketamine or propofol
Ketamine (per Dr. B)
89
Which med can cause centrally mediated muscle relaxation?
Benzos
90
Elderly have ________ volume in their central compartment so you would ________ propofol dose
Decreased
Decreased
91
Peds have ________ volume in their central compartment so you would ________ propofol dose
Increased
Increased
92
If you don't have methohexital (brevital) then you can give ___________
etomidate
93
Onset of Propofol
9-51 sec (average 30 sec)
94
DOA of propofol
3-10 min
95
Induction dose of propofol
1-2.5 mg/kg
96
Pt w/ high risk PONV & MH. What induction agent should you use?
Propofol
97
Symptoms of propofol infusion syndrome
-Hypertriglyceridemia
-Metabolic acidosis
-Rhabdomyolysis
-Renal failure
-Hemodynamic instability
98
Propofol infusion syndrome is associated with high dose infusions for > ___ hours
48 hrs
99
The Dissociative Anesthetic
Ketamine
100
Why does ketamine cause dissociation?
Depresses the medial thalamic nuclei & blocks the association between the thalamus and the cerebral cortex
101
Ketamine depresses the ________ _________ __________ & blocks the association between the ________ and the cerebral cortex
-medial thalamic nuclei
-thalamus
102
Ketamine is derived from _______
PCP
103
(t/f) Ketamine has minimal effects on respiratory drive and airway reflexes
True
104
Using ________ can decrease the emergence delirium caused by ketamine by ___%
-benzos
-50%
105
Ketamine MOA
NMDA Receptor antagonist in the spinal cord and brain
*Selective depression of the medial thalamic nuclei
106
Ketamine causes increased __________ which can lead to ____________ (emergent scenario)
-salivation
-laryngospasm
107
Metabolite of ketamine
Norketamine
108
Norketamine is ____ -____ as potent as ketamine
- 1/3rd - 1/5th
109
Onset of ketamine
1-2 min
110
DOA of ketamine
5-15 min
111
Ketamine stimulates endogenous _________ release
catecholamine
112
Ketamine induction dose
1-2 mg/kg
113
GABA stands for __________
Gamma-aminobutyric acid
114
Ketamine is the only true _____________ (think airway)
-bronchodilator
115
Hypovolemic pts can benefit from what induction agent especially
Ketamine
116
What induction agent has relatively low protein binding when compared to other agents
Ketamine
117
What drug commonly causes a cataeleptic state
Ketamine
118
You see ur pt w/ eyes open, pupils reactive to light, corneal reflexes intact, lacrimation, blinking, involuntary muscle movement. You induced w/ ketamine. Is this ok?
Yes
Normal cataeleptic state caused by ketamine
119
List some big C/I co-morbidities w/ ketamine administration
-CHF
-CAD
-uncontrolled HTN
-neuro and cererbral aneurysms
120
Dexmetomidine ratio of α2:α1 = _____:__
1620:1
121
Dexmedetomidine MOA causes analgesic effects at the spinal cord and a supraspinal site called the __________ ___________
Locus Ceruoleus
122
Name the 3 main MOAs of dexmedetomidine
-a2 agonist
-hyperpolarization of neurons via K+ efflux
-Inhibits adenyl cyclase
(decreases cAMP)
123
Dexmedetomidine typically decreases HR & BP, however initially direct effects on peripheral
α2 receptors can predominate
leading to __________ BP
Increased BP
124
Dexmedetomidine can cause significant hypotension in patients with increased sympathetic tone such as __________, ___________ and ____________
Diabetics
Hypovolemics
Elderly
125
Neuro wise, dexmedetomidine only decreases _______
CBF
126
Dexmedetomidine onset
5-10 min
127
Dexmedetomidine DOA
60-120 min
128
Dexmedetomidine Infusions should not exceed ___ hours
24 hrs
129
Loading dose of dexmedetomidine
0.5-1 mcg/kg over 10 min
130
Respiratory effects of dexmedetomidine
Preserved - possible small to moderate decrease in TV
Decreased salivation
131
Main cardiac effects of dexmedetomidine
Bradycardia
Hypotension
132
Dexmedetomidine can be used to tx __________
Shivering
