Induction Agents Flashcards
(110 cards)
1
Q
what are the names of the stages of anesthesia according to unit 2
A
analgesia, delirium, surgical anesthesia, and medullary paralysis
2
Q
a patient in stage 1 of anesthesia should be able to
A
open their eyes on command, breathe normally, maintain airway, and tolerate mild stimuli
3
Q
what might you see during stage 2: delirium of anesthesia
A
cv instability, rapid ocular movements, laryngospasm, emesis
4
Q
how long does stage 2 of anesthesia typically last
A
30s-1 min
5
Q
5 components of surgical anesthesia
A
hypnosis, analgesia, muscle relaxation, sympatholysis, and amnesia
6
Q
in stage 4 of anesthesia the patient is experiencing
A
loss of all reflexes, marked hypotension and flaccid paralysis
7
Q
what is the gold standard induction agent
A
barbiturates
8
Q
MOA of barbiturates
A
potentiate GABA A activity; mimics GABA with activity on glutamine, adenosine, and neuronal nach receptors
9
Q
barbiturates do what to CBF and CMRO2
A
decreases by 55%
10
Q
cerebral vasoconstriction is a positive attribute of barbs because
A
it decreases CBF and CMRO2 and has anticonvulsant properties
11
Q
barbiturates have no
A
analgesic properties
12
Q
barbiturates have a rapid onset and awakening due to
A
rapid redistribution
13
Q
with prolonged infusion, barbs have
A
a long context sensitive half time
14
Q
at 30 minutes, how much barbiturate is left in the brain
A
10%
15
Q
what is the site of initial redistribution of barbs
A
skeletal muscle
16
Q
we dose barbiturates on
A
ibw
17
Q
excretion of barbiturates is through
A
kidneys
18
Q
where are barbs metabolized
A
hepatocytes
19
Q
what do barbiturates preferentially bind
A
albumin 70-85%
20
Q
a non ionized drug favors an
A
acidic environment
21
Q
an ionized drug favors an
A
alkalotic environment
22
Q
what is the fat/blood coefficient for thiopental
A
11
23
Q
E 1/2 time of thiopental is longer than
A
prop and etom
24
Q
methohexital has a ______ lipid solubility than pentothal despite having a _____ non ionized form
A
lower; 76%
25
What excitatory phenomena is methohexital associated with
hiccoughs and myoclonus
26
a continuous infusion of methohexital could cause
post op sz activity
27
methohexital causes seizures in patients undergoing temporal lobe resections d/t lowering the seizure threshold; but during this procedure, it may decrease sz duration
ECT
28
list the most important CV side effects of methohexital and the dose associated with it
when given 5 mg/kg, we can see a decrease in sbp 10-20 mmhg, a decrease in hr 15-20 bpm; we can see histamine release and may need to have vasopressin ready; and we can see lack of baroreceptor response in patients with CHF, hypovolemia, and beta blockade
29
list the most important pulmonary effects of methohexital
depresses medulla and pontine causing apnea; makes patient less sensitive to CO2 causing slow return to spontaneous ventilation
30
in someone who has a decreased ventilatory drive, how would we prepare for extubation
slow the frequency of the vent, decrease tidal volume, and let CO2 build up to trigger spontaneous respiration
31
what kind of monitoring is required for administration of barbiturates
somatosensory evoke potential or SSEP
32
what is one side effect to be wary of that may occur days after the administration of barbs
enzyme induction appx 2-7 days post infusion; especially can deactivate anticoagulants
33
rapid injection of propofol will can unconsiousness in
30s
34
lecithen is associated with
egg yolk
35
MOA of propofol
modulator of GABA A receptor causing transmembrane chloride conductance to increase
36
where is propofol cleared the most
the lungs
37
main metabolism of prop is
cyp450
38
e 1/2 time of propofol
30 mins to 1 1/2 hours
39
context sensitive half time of an 8 hour propofol infusion
40 minutes
40
the context sensitive half time of prop is shorter than
barbiturates
41
what are props' metabolites
glucuronide and sulphate
42
what is cleared the fastest between ketamine, propofol, and etomidate
propofol
43
propofol will do what to blood pressure and heart rate
decrease it
44
etomidate will do what to blood pressure and heart rate
have no effect
45
ketmine will do what to blood pressure and heart rate
increase it
46
are we concerned about giving propofol to people with renal disease, liver disease, or pregnancy? why?
the drug can be metabolized elsewhere besides the liver; there is no influence on the kidneys for clearance; the fetus can rapidly clear propofol
47
TIVA stands for
total IV anesthesia or balanced anesthesia
48
children require higher doses of propofol because
they have a larger distribution volume and clearance rate
49
what % would we consider lowering the dose of prop for elderly patients
25-50%
50
propfol has these unconventional benefits
anti itch, antiemetic, antioxidant properties
51
list the CNS side effects of propofol
decreases CMRO2 , CBF, and ICP; large doses may decrease CPP; myoclonus; no SSEP suppression
52
list the CV side effects of propofol
decreased SBP, SVR, SNS response, intracellular calcium, and baroreceptor reflexes - may have profound bradycardia and asystole with healthy adult patients; some s/e can be modulated by DL stimulus
53
list pulm side effects of propofol
dose dependent suppression of ventilation; lungs maintain hypoxic drive; painful surgical stimulation counteracts ventilatory depressant effects
54
surigcal infusions of propofol don't cause any hepatic or renal issues; however, prolonged infusions may cause
hepatocellular injurt, PRIS, green urine from phenols, and cloudy urine
55
what is PRIS and what elements are involved
propofol infusion syndrome; > 75 mcg/kg/min doses; can cause fatal bradycardia in children; lactic acidosis, bradydysrhythmias, and rhabdo
56
name some miscellaneous s/e of propofol
decrease IOP, pain on injection, inhibition of platelet aggregation, allergic reactions, prolonged myoclonus
57
Oxybarbituates such as methohexital have an oxygen in their second position; thiopental has what element in its second position that makes it more lipid soluble
sulfur
58
what ring is present in etom
imidazole
59
etom is ___ soluble in acid and ____ soluble in physiologic pH
water; lipid
60
what percent of etom is propylene glycol
35%
61
etom has a high incidence of
myoclonus
62
etom onset
1 minute
63
what percent bound is etom to albumin
76%
64
how is etom metabolized
hydrolized by hepatic microsomal enzymes
65
e 1/2 time of etom
2-5 hours
66
how is etom eliminated
in the urine
67
etom is cleared 5x faster than
thiopental
68
etom is best for patients with an
unstable cv system
69
does etom have analgesic properties
no
70
from greatest to least, list some induction agents by myoclonus incidence
etom, thiopental, methohexital, propofol
71
how can we offset the incidence of myoclonus with admin of etom
give 1-2 mcg/kg fentanyl
72
adrenocortical suppression is common in what drug? what does it cause
etom; severe HPN and increase in mechanical ventilation time
73
enzyme inhibition of etom can last
4-8 hours after initial dose
74
caution in giving etom to
sepsis and hemorrhaging patients; sz patients d/t myoclonic effect
75
list the most significant cns effects of etom
decreases cbf and cmro2 by 35-45%; decreases ICP; more frequent excitatory spikes on eeg; may activate sz foci and increase amplitude of SSEP
76
list the most significant cv effects of etom
minimal changes in hr, sv, co, and contractility; at high doses, may cause sudden hpn with hypovolemia
77
list the most significant pulm effects of etom
less potent ventilatory depressant than thiopental; rapid iv injection will cause apnea; decreases in Vt are offset by compensatory increase in respiratory rate; stimulates co2 medullary centers
78
ketamine is a derivative of
pcp - phenylcyclidine
79
ketamine has both ____ and ____ properties
analgesic and amnestic
80
what would you expect to see in a pt after administration of ketamine
slow nystagmus; wakefulness, but noncommunicative; hypertonus and purposeful skeletal muscle movement
81
etom has no ____ __ _______ like propofol does
no pain on injection
82
what is the preservative behind ketamine
benzothonium chloride
83
S-ketamine has what better analgesic effects
2x greater than racemic and 4x greater than r-ketamine
84
racemic ketamine acts like which illicit drug? in what way?
cocaine in that it blocks reuptake of catecholamines
85
primary excitatory nt in the cns
glutamate
86
which kind of binding does ketamine do and where does it bind
non competitive to the nmda receptor and opioid receptors
87
ketamine has weak action here
gaba and sigma receptors
88
peak plasma concentration of ketamine in
1 minute
89
duration of action of ketamine
10-20 mins
90
ketamine is _x more lipid soluble than thiopental
5-10
91
Vd of ketamine
3 L
92
e 1/2 time of ketamine
2-3 hours
93
ketamine is cleared and metabolized by
the liver
94
active metabolite of ketamine
norketamine
95
ketamine is excreted by
the kidneys
96
tolerance to ketamine is most likely to develop in
burn patients
97
5 different dosages of ketamine are for
induction, maintenance, subanesthetic (analgesic), neuraxial, post op pedi hearts
98
ketamine increases salivation; what can we give to combat this
glycopyrrolate
99
full consciousness returns after how many minutes after admin of ketamine
60-90 mins
100
clinical uses for ketamine
asthmatics, MH, hypovolemia; CAD cocktail; burn dressing changes; psychiatry; restless leg syndrome; reversal of opioid tolerance;
101
avoid using ketamine in
pulm and systemic htn and patients at risk for high icp
102
list the cns effects of ketamine
potent cerebral vasodilator --> increased icp, and increases cbf by 60%; myoclonus; increased amplitude of SSEP
103
list the cv effects of ketamine
resembles sns stimulation; unexpected drops in sbp due to depleted catecholamine stores
104
list the pulm effects of ketamine
no sig depression of ventilation; ventilatory response to co2 is maintained; upper airway skeletal muscle tone and reflexes remain intact; bronchodilator activity
105
psychedelic effects of ketamine are? due to? how long might they last?
morbid vivid colored dreams and hallucinations; due to depression of the inferior colliculus and medial geniculate nucleus; may last 24 hours
106
we can prevent emergence delirium by giving
benzos before ketamine
107
name some miscellaneous s/e of ketamine
inhibition of plt aggregation, free ca, and plasma cholinesterase
108
ketamine may enhance the effects of these drugs
succs - prolonged apnea; nmdbs - prolonged paralysis; volatile anesthetics - decrease sns stimulus
109
we can blunt the effects of ketamine on the sns by
administering benzos, volatiles, or n20 (nitrous)
110
ketamine may be good for osa because
it maintains upper airway reflexes
