Induction Agents Flashcards
(138 cards)
1
Q
Propofol
Induction dose:
MAC Sedation Dose:
A
1-2.5 mg/kg IV
MAC — 25-75 mcg/kg/min
2
Q
The general anesthesia sedation/maintenance dose of Propofol is:
A
25-200 mcg/kg/min
3
Q
Indications for Propofol (5)
A
Induction and MAC
TIVA
Outpatient surgery and endoscopy
Antiemetic
Malignant Hyperthermia
4
Q
MOA of Propofol:
A
GABA agonist
5
Q
Cardiac and respiratory effects of Propofol:
A
Decreases CO, BP, SVR (slight decrease in HR until pt is asleep then increases to compensate for CV decreases)
dose-dependent respiratory depression
Decreased Vt
Increased RR (at maintenance doses)
Bronchodilator (direct effect on intracellular Ca++)
6
Q
T or F: Propofol is a neuro protective drug
A
T
7
Q
Propofol CNS effects:
A
- neuroprotective — decrease CBF, CMRO2, and ICP & decreased SVR may cause decreased CPP
- anticonvulsant
8
Q
Contraindications of Propofol (3)
A
Allergies to soybean oil or soy products
Allergies to egg and egg products
Allergies to sulfite
9
Q
Correct onset and duration of Propofol:
A
Onset: <1 min
**”30 seconds or so…”
Duration: dose and rate dependent
10
Q
Metabolism of Propofol occurs in:
A
Hepatic
Kidney and lungs (account for ~ 30%)
11
Q
Excretion of Propofol is via:
A
Renal System
12
Q
unconventional use of propofol and MOA
A
10 mg IV for PONV and pruritis
MOA related to spinal cord suppression
13
Q
T or F: propofol is good for WPW ablations because it has no AV or SN node depression
A
T
14
Q
clinically when you should avoid propofol use
A
cardiac unstable or hemorrhaging
15
Q
is propofol lipid soluble
A
yes
16
Q
protein binding of propfol
A
97-99%
17
Q
why can propofol injections be painful and what can you do to decrease it
A
glycerol; lidocaine 1 mg/kg
18
Q
T or F: propfol has analgesic effects
A
F
19
Q
T or F: Propofol is a chiral compound
A
F– not chiral
20
Q
how is propofol partially reversed
A
physostigmine
21
Q
induction dose of Ketamine:
IV
IM
A
1-2 mg/kg IV; 4-5 mg/kg IM
***in low dosing can be opioid sparing
22
Q
infusion dose of Ketamine
A
1-2 mg/kg/hr
23
Q
other name for Ketamine
A
Ketalar
24
Q
other name for propfol
A
diprivan
25
indication for Ketamine (6)
- induction
- sedation
- sedation for mentally challenged or non-compliant such as kids
- CV collapse
- “bad” epidural/spinal
- Good for OB.
- tamponade ***she didnt say this !?
26
contraindication of Ketamine (4)
- Right heart dysfunction (**decreases PVR**)
- increased ICP
- Critically ill/shock pts ( **catecholamine depletion** r/t shock — will cause profound hypotension and unopposed direct **myocardial depression**)
- psych patients (will make them hallucinate)
27
MOA of Ketamine (3)
- noncompetitive NMDA antagonist that blocks *glutamate*
- stimulates the SNS: *inhibits* the reuptake of norepi
- dissociative anesthesia — **dissociation btwn thalamocortical and limbic system**
28
CV system effects of Ketamine
- increase BP, HR, CO, PAP, CVP, CI
- increases myocardial O2 requirements
29
in what CV patient should you be especially cautious of using Ketamine
pt with severe RIGHT heart dysfunction
30
Respiratory system effects of Ketamine (4)
- minimal depression
- maintain upper airway reflexes
- increased oral secretions (effects on *muscarinic* receptors)
- bronchodilator (used in **bronchospasm dilator**)
31
Neuro system effects of Ketamine (5)
- cerebral dilator (increased ICP)
- potential to produce myoclonic activity (usually considered an anticonvulsant though)
- prolongs and enhances effects of NMBDs
- emergence delirium
- Hallucinogenic: *phencyclidine* derivative
32
other system effects of Ketamine
- increased lacrimation and salivation --> premedicate with anticholinergic
33
what are a few clinical judgments necessary for Ketamine? (4)
- used in OB (NOT preeclamptic)
- ketamine dart 3-4 mg/kg for mentally challenged
- not good for brain lesions d/t increased ICP
- MAY be used as a last resort for status epilepticus
34
onset of Ketamine
IV
IM
IV- 30 seconds
IM 2-4 minutes
35
duration of Ketamine
IV
IM
IV 10-15 min
IM 15-25 min
36
metabolism of Ketamine
hepatic by demethylation via CYP 450
*active metabolite, **Norketamine**, is 1/3-1/5 as potent
37
excretion of Ketamine
Renal
38
T or F: Ketamine provides analgesia w/o airway compromise
T
39
more potent stereoisomer of Ketamine
S (+)
40
T or F: for Ketamine, there is a functional dissociation between thalamocortical and limbic systems
T
41
protein binding of Ketamine
only anesthetic that has low protein bind (12% or 20% depending on source)
42
describe the cataleptic state of Ketamine
pt eyes remain open with slow nystagmic gaze
43
other name for Thiopental
pentathol
44
induction dose of Thiopental
3-5 mg/kg IV
45
how should you adjust the induction dose of Thiopental for elderly
reduce by 30%
46
indications for Thiopental (4)
- induction/sedative
- hypnotic
- anticonvulsant
- treatment of ICP (Neuro cases)
47
contraindications of Thiopental (3)
- Acute intermittent Porphyria
- variegate Porphyria
- status asthmaticus (**d/t histamine release)
48
MOA of Thiopental (2)
- activates GABA — short acting barbituate
- decreases RAS (small histamine release)
49
CV effects of Thiopental
**Hypotension**
*Depresses myocardium and relaxes vascular smooth muscle*
50
respiratorey effects of Thiopental
resp depression
51
Neuro effects of Thiopental (3)
- potent cerebroconstrictor
- decreased CBF
- decreased ICP
52
GI effects of Thiopental
N/V
53
T or F: Thiopental has analgesic effects
F- may actually lower pain threshold; thus increasing sensitivity to pain
54
onset of thiopental
30-60 seconds
55
duration of Thiopental
5-30 min
56
metabolism of Thiopental
hepatic
57
half life of Thiopental
12 hours
58
protein binding of Thiopental
80%
** its actually 72-86%**
59
what does Thiopental precipitate with
- lidocaine
- roc
- succs
*THIs LIghter Really Succs*
60
important things to know about Thiopental (5)
- extravation= necrosis
- accidental arterial injection= severe vasoconstriction
- sulfur on 2nd C atom
- "hangover feeling"
- pt can experience garlic/onion taste
61
other name for etomidate
amidate
62
induction dose of etomidate
0.2-0.3 mg/kg
63
infusion dose of etomidate
5-20 mcg/kg/min
64
indications for etomidate (2)
- induction
- procedural sedation
65
MOA of etomidate (3)
GABA agonist (*increases Cl- influx, hyperpolarizing cell*)
Short acting **non-barbituate** hypnotic
Depresses RAS
66
CV and respiratory effects of etomidate
CV- minimal effects
resp- depression
67
neuro effects of etomidate
- **potent cerebroconstrictor** decreases CMR, CBF, ICP
- myoclonus **decrease with opioids**
68
GI effects of etomidate
N/V
69
other system effects of etomidate
- adrenocorticol supression
70
in what type of patient is etomidate a good choice for
- cardiac patients with low EF
71
what procedures/ patients should you use clinical judgment for use of etomidate
- ECT (prolong seizure duration)
- trauma
- elderly patients
72
onset of etomidate
30-60 seconds
73
duration of etomidate
3-5 min
**Pharm says 5-10 minutes**
74
metabolism of etomidate
hepatic and plasma ester hydrolysis
75
excretion of etomidate
renal (80%)
Bile (20%)
76
protein binding of etomidate
76%
77
more potent isomer of etomidate
R (+)
78
does etomidate have hypnotic and analgesic effects
hypnotic- yes
analgesic- no
79
other name for dexmedetomidine
precedex
80
procedural sedation dexmedetomidine:
For sedation:
For infusion:
Sedation: 0.5-1 mcg/kg over 10 min
Infusion: 0.3-0.7 mcg/kg/hr
81
awake fiberoptic intubation and infusion dose of dexmedetomidine
intubation: 1 mcg/kg over 10 min
infusion: 0.7 mcg/kg/hour until intubated
82
indications for dexmedetomidine (4)
- pediatrics
- analgesia (acts on **mu, delta, kappa receptors**)
- procedural/Postop sedation
- awake fiberoptic intubation
83
contraindications for dexmedetomidine
- AV block
- 1st degree HB
84
MOA of dexmedetomidine
- highly selective potent **central acting** alpha-2 adrenergic agonist (*inhibit release of norepinephrine*)
85
CV effects of dexmedetomidine
- bradycardia
- sinus arrest
- hypotension
- rebound HTN
*Tx: w/ atropine/ephedrine/volume*
86
respiratory effects of dexmedetomidine
Minimal depression
- less vent depression than other agents
- bonus can decrease minute ventilation
87
onset and peak of dexmedetomidine
onset: 5-10 min
Peak: 15-30 min
88
duration of dexmedetomidine
1-2 hours (dose-dependent)
89
metabolism of dexmedetomidine
hepatic
90
excretion of dexmedetomidine
renal
91
protein binding of dexmedetomidine
94%
92
dexmedetomidine provides what *CNS* dose dependent effects (3)
- analgesia
- anxiolysis
- sedation
93
Which is more alpha selective:
dexmedetomidine or clonidine
dexmedetomidine
94
the hypnotic efects of dexmedetomidine occur in:
locus coeruleus
95
where do the analgesic effects of dexmedetomidine occur
level of spinal cord
96
T or F: can develop tolerance and dependence of dexmedetomidine
T
97
What effects does dexmedetomidine have on the CYP 450 system
inhibitory properties that can increase plasma concentrations of opioids
98
another name for methohexital
brevital
99
induction dose (and concentration) of methohexital
1-1.5 mg/kg
Concentration: 500 mg vial reconstituted with 50 cc NS (1% solution —> 10 mg/cc)
100
indications for methohexital (3)
- ECT
- Endo
- very short procedures
101
contraindications for methohexital
- acute intermittent porphyria
- variegate porphyria
102
MOA of methohexital
enhances GABA— rapid ultrashort acting barbiturate
103
system effects of methohexital (4)
- skeletal muscle hyperactivity
- deep sedation
- pain on injection
- Lowers seizure threshold
104
methohexital useful in what procedures clinically and why
- ECT--> lower seizure threshold
- Endo--> used when shortage of propofol (very short procedures).
105
onset and duration of methohexital
onset: < 1 min
duration: 5-7 min
106
metabolims of methohexital
hepatic
107
excretion of methohexital
Renal
108
protein binding of methohexital
75-85%
109
what med should you be catious of when using methohexital
atropine-- it precipitates with it
110
chemical property of methohexital
oxygen retained on the 2nd C atom
111
In what 6 groups should we use propofol cautiously and how should each groups dose be adjusted? (6)
1. Children — **Need more** large Vd and quicker clearance= need more
2. Chronic ETOH — **Need more** d/t enzyme abuse
3. Obese — **Depends** base dosing on lean body weight
4. CV disease — **Need less** d/t propofol decreasing SVR
5. Trauma/hypotensive/bleeding — **Need less** d/t the decrease in SVR, BP, CO, SV
6. Elderly — **Need less** decreased sensitive, prolonged effects d/t decreases CO and clearance
112
Dose of lidocaine
0.5-1.5 mg/kg (dose depend on pt and provider)
113
Why is lidocaine used on induction (4)
- suppress coughing reflex during laryngoscopy/intubation/EGDs
- reduce airway responsiveness to noxious stimuli
- reduce pain from IV injected agents
- Can attenuate the intracranial hypertensive response to laryngoscopy/intubation.
114
Lidocaine might increase hypotensive effects of
Sedative-hypnotic agents
115
Why should you use caution when administering lidocaine to cardiac patients
- indirect evidence that it can attenuate intracranial hypertensive response to laryngoscopy and intubation
- lidocaine (1.5 mg/kg) given 3 min before intubation suppresses cough reflex and attenuates increased airway resistence resulting from laryngoscopy and ETT intubation
116
How can you prevent emergence delerium from ketamine
- low lights
- quiet room
- versed (2 mg as pretreatment)
117
T or F: KEtamine causes intense analgesia
T
118
Ketmine dose for bronchospasms
0.2-1.0 mg/kg IV
119
Active metabolite of ketamine and how “active “ is it?
Norketamine
1/3-1/5 as potent as ketamine
120
Level of histamine release from thiopental use
“Some”
121
How can you decrease myoclonic movements with etomidate
Opioids
122
How can you treat Precedex induced hypotension
Atropine
Ephedrine
Volume
123
T or F: Methohexital has anticonvulsant activity
F — does not have anticonvulsant activity (lowers seizure threshold)
124
For intermittent IV use of methohexital, how should it be reconstituted
Into 1% (10 mg/cc)
125
T or F: Methohexital has a slow redistribution
F— **RAPID**
126
____________ is the shortest-acting barbiturate and (does/does not) have anticonvulsant activity. It (lowers/increases) the seizure threshold.
Methohexital
Does not
Lowers (this is why its good for ECT)
127
Etomidate is a ____________ derivative
Carboxylated imidazole
128
Ketamine has (low/high) lipid solubility
High
129
How do we dose ketamine when using for a “bad spinal/epidural”
1. 2 mg Versed
2. Ketamine in 10-20 mg doses at a time until pt is unresponsive to glabellar tap, still breathing, not screaming
3. If they even bat an eyelash, immediately give 10 mg more
4. Repeat until procedure is finished
130
Lidocaine dose
What do we typically give and when must we adjust it?
1 mg/kg (range is 0.5-1.5 mg/kg)
Typically give 100 mg of 2% solution (5 cc); adjust this for both patients weighing less than 60 kg, as well as hemo unstable
131
Why don’t we mix propofol and lidocaine in same syringe
After 20 mins, the effect of Propofol are negated and lipid emulsion broken up **(risk for embolism)**
132
Propofol:
N/V rescue dose-
N/V background infusion dose -
What MOA is this?
10-15 mg
10-20 mcg/kg/min
Direct effect on CTZ
133
Cause of PRIS and how is it recognized clinically?
Occurs with propofol doses 4 mg/kg/hr > 48 hours or 67 mcg/kg/min
Bradycardia, EKG changes, Arrhythmias
134
For which patients would we use TIVA rather than inhalational GA
History of PONV or MH
135
How do we know pt is unconscious/sedated during TIVA if they are muscle relaxed?
Use BIS (40-60 is ideal for GA)
136
How does etomidate cause adrenocortical suppression and for how long?
Inhibit 11 B hydroxylase enzyme (Effects last 4-8 hours after induction dose of etomidate)
137
CNS Ketamine effects
- potent cerebral vasodilator
- increase CBF by 60-80% (*hyperventilate* to attenuate effects)
- relatively C/I in pt with elevated ICP
138
Propofol S/E (3)
- injection pain (d/t glycerol)
- allergies/anaphylaxis (d/t *phenyl nucleus and di-isopropyl side chain*)
- PRIS (*bradycardia, ekg changes, arrhythmias*)
