Induction Agents Flashcards
1
Q
Propofol Dosing
A
- Induction: 1-2.5 mg/kg OR 2 mg
- Sedation maintenance: 25-200 mcg/kg/min
2
Q
Propofol Onset/Duration
A
Onset: 30 sec
Duration: dose & rate dependent
3
Q
Propofol MOA
A
- GABAa agonist (stimulates these receptors)
- Highly lipid soluble
4
Q
Propofol contraindications
A
- soy allergy
- egg allergy (proteins trigger egg allergy; prop is made from egg white; still avoid to be safe)
5
Q
Propofol CV effects?
A
- decrease HR
- decrease SVR
- decrease BP
not a good choice for low CO states, hypovolemia, and hypotension
6
Q
Propofol CNS effects?
A
- decrease CBF
- decrease ICP
- decrease CMRO2
- loss of consciousness
- anticonvulsant
- minimal residual CNS effects due to fast on/fast off
7
Q
Propofol respiratory effects?
A
- respiratory depression (dose-dependent)
- apnea
- bronchodilation
8
Q
Propofol protein binding
A
97 - 99%
9
Q
How is propofol metabolized?
A
- mostly by the liver
- kidney and lungs (30%)
10
Q
When is propofol used?
A
- TIVA
- induction
- outpatient surgery
- endoscopy
- MAC
- antiemetic (10-15mg)
- antipuritis (10mg)
11
Q
Propofol bacteria considerations
A
- 12 hours in an opened infusion vial
- 6 hours in a syringe
12
Q
Elderly considerations with propofol?
A
more sensitive and prolonged effects due to decreased CO and clearance (may need lower dose)
13
Q
Pediatric considerations with propofol?
A
may need larger dose because of larger Vd and quicker clearance
14
Q
Obesity considerations with propofol?
A
base dosing on lean body weight (LBW), NOT by actual body weight
15
Q
In what cases would a patient need higher doses of propofol due to decreased sensitivity?
A
- chronic alcoholism
- daily marijuana use
16
Q
In what cases would a patient need lower doses of propofol due to increased sensitivity?
A
- CV disease
- elderly
17
Q
What can we expect with higher doses of propfol and rapid clearance?
A
ramped up liver enzymes
18
Q
Lidocaine Dosing
A
0.5 - 1.5 mg/kg
19
Q
What is the concentration of 1% lidocaine?
A
10 mg/ml
20
Q
What is the concentration of 2% lidocaine?
A
20 mg/ml
21
Q
When is lidocaine used?
A
- suppress coughing reflex during laryngoscopy, intubation, and EGD
- reduce airway responsiveness to noxious stimuli
- reduce pain caused by IV injection agents
- drip for ERAS protocols (enhanced recovery after surgery)
22
Q
What can be used to decrease painful injection of propofol?
A
lidocaine
23
Q
Lidocaine is given at a dose of ______ and administered _______ minutes before intubation or extubation to __________ and _________
A
- 1.5mg/kg
- 3 min
- suppress cough reflex
- attenuate the increase in airway resistance from laryngoscopy and intubation
24
Q
Careful for lidocaine use in _________ patients due to ___________
A
- cardiac patients
- hypotensive effects
25
What is the effect of lidocaine on CBF?
decrease CBF and attenuate intracranial hypertensive response to laryngoscopy and intubation
26
What is the most common and effective ERAS lidocaine drip dosing?
1-2 mg/kg/hr
27
What is the rationale for administering a lidocaine infusion per ERAS protocol?
- analgesia
- ANTI-hyperalgesia
- ANTI-inflammatory
28
What is the concentration in a lidocaine infusion bag?
4 mg/ml
1 gm lidocaine in 250ml
OR
2 gm lidocaine in 500 ml
29
What is the MOA of ketamine?
- noncompetitive NMDA receptor antagonist that blocks glutamate
- stimulates SNS; inhibits reuptake of norepinephrine
30
Ketamine is considered a ___________ anesthetic
dissociative anesthetic
31
What is ketamine used for?
- induction
- sedation
- patients with CV collapse
- sedation for mentally challenged
- "bad" epidural/spinal
- trauma induction
32
Ketamine CV effects?
- increase in BP
- increase in HR
- increase in CO
- increase in PAP
- increase in CVP
- increase in CI
33
Ketamine respiratory effects?
- minimal respiratory depression
- able to maintain upper airway reflexes
- increased oral secretions (may give 0.2mg of glycopyrrolate)
- major bronchodilator (great for patient that is actively wheezing)
34
Ketamine stimulates SNS or PNS? What effects will be seen?
- stimulates SNS
- increased HR, SVR, BP
35
How does ketamine cause intense analgesia?
Binds to opioid receptors (mu, kappa, delta)
36
Children are at risk for ___________ when administered ketamine
emergence delirium
37
What are ways to prevent emergence delirium with ketamine?
wake up in low lights, quiet room, no cartoons on TV, administer versed
38
What agent can be given to prevent emergence delirium with ketamine?
versed
39
Ketamine Dosage
IV: 1-2 mg/kg
IM: 4-5 mg/kg
40
Ketamine onset and duration
Onset: 30 sec (IV), 2-4 min (IM)
Duration: 10-15 min (IV), 15-25 min (IM)
41
____________ is an active metabolite of ketamine. It is ________________ potent as ketamine
- norketamine
- 1/3 - 1/5
42
What agent is considered a phencyclidine derivative and hallucinogenic?
ketamine
43
Ketamine is part of what protocol?
bronchospastic protocol
44
Bronchospastic protocol treatments
1. 100% O2
2. change I:E for longer exhalation
3. deepen volatile anesthetic
4. r/o mainstem intubation or kinked ETT. suction
5. inhaled beta 2 agonist or anticholinergic
6. epi 10 mics (if severe)
7. ketamine 0.2 - 1.0mg/kg
8. hydrocortisone 100mg
9. nebulized racemic epi
10. r/o anaphylaxis
11. ABG
45
Thiopental Dosing
3-5 mg/kg IV
46
Thiopental onset and duration
Onset: 30-60 sec
Duration: 5-30 min
47
How is thiopental metabolized?
hepatic metabolism
48
What is thiopental used for?
- sedative/hypnotic
- anticonvulsant
- treatment of ICP
- induction of anesthesia
49
What are contraindications to administering thiopental?
- acute intermittent porphyria (variegate porphyria)
- status asthmaticus
50
Protein binding of thiopental?
72 - 86%
51
Thiopental MOA
short acting barbituate that activates GABA receptors
52
T/F: Thiopental is a benzodiazepine
false
thiopental is a barbiturate (thiobarbiturate)
53
What is the effect of thiopental on BP?
hypotension
54
What is the effect of thiopental on CNS?
- sedation
- LOC
- decrease in CBF
- decrease in ICP
55
T/F: Thiopental has some histamine release
true
56
Which drug is still studied in anesthesia but no longer used in the US?
thiopental
57
T/F: thiopental does not cause nausea/vomiting
false
thiopental may increase N/V
58
Thiopental may cause ____________, which can lead to _______________
- extravasation
- necrosis
59
Etomidate Dosing
0.2 - 0.3 mg/kg
60
Etomidate onset and duration
Onset: 30 - 60 sec
Duration: 2 -3 min
61
Protein binding of etomidate
76%
62
Mechanism of action of etomidate
- ultrashort-acting non-barbiturate hypnotic
- depresses RAS via activating GABA
63
What are the uses for etomidate?
- induction
- procedural sedation
64
Etomidate CV effects?
minimal CV effects
65
Etomidate CNS effects?
- decrease CMRO2
- decrease CBF
- decrease ICP
- sedation
- LOC
- myoclonic movements
66
Etomidate has the potential to cause _____________ which can be decreased with opioids
myoclonic movements
67
Etomidate respiratory effects?
respiratory depression
68
What is a major risk of etomidate?
adrenocortical suppression
69
Why don't we use etomidate for long-term use?
Potential for adrenocortical suppression
70
How is etomidate metabolized?
hepatic enzyme and plasma esterase hydrolysis
71
Dexmedetomidine MOA
- highly selective and potent alpha2 adrenergic agonist
- inhibits norepinephrine release
72
When is dexmedetomidine used?
- sedation
- analgesia
- anxiolysis
- awake fiberoptic intubation
- postop sedation
- post exubation to keep calm
- pediatrics
73
CV effects of dexmedetomidine?
- BRADYCARDIA (esp with bolus)
- sinus arrest
- hypotension
74
How are CV effects from dexmedetomidine treated?
- atropine
- ephedrine
- volume/fluids
75
T/F: dexmedetomidine has minimal respiratory depression effects
true
76
Protein binding of dexmedetomidine?
94%
77
Dexmedetomidine Dosing
- Procedural sedation: 0.5 - 1 mcg/kg bolus over 10 min, then 0.3 - 0.7 mcg/kg/hour infusion
- Awake fiberoptic intubation: 1 mcg/kg bolus over 10 min, then 0.7 mcg/kg/hour infusion
78
Dexmedetomidine onset, peak, and duration
Onset: 5-10 min
Peak: 15-30 min
Duration: 60-120 min
79
How is dexmedetomidine metabolized and excretion?
- hepatic metabolism
- urinary excretion
80
What is methohexital used for?
- electroconvulsive therapy (ECT)
- endoscopy
- very short procedures
81
Methohexital MOA
- GABA agonist
- rapid ultrashort-acting barbiturate
82
T/F: methohexital is a barbiturate
true
methohexital is an oxybarbiturate
83
Methohexital Dosing
1 - 1.5 mg/kg
84
Methohexital onset and duration
Onset: < 1 min
Duration: 5 - 7 min
85
T/F: methohexital is the shortest acting barbiturate
true
86
Methohexital has _____________ activity and ____________ seizure threshold, which is why it is good for ____________
Methohexital has PROCONVULSANT activity and LOWERS seizure threshold, which is why it is good for ECT
87
Methohexital must be ______________ into a ____________ solution in ___________
- reconstituted
- 1% (10 mg/ml) solution
- in sterile water
88
Effect of methohexital
- deep sedation
- skeletal muscle hyperactivity
89
T/F: methohexital is not painful on injection
false
methohexital is painful on injection
90
How is methohexital metabolized and excreted?
- hepatic metabolism
- urinary excretion
91
Why does methohexital have short onset and duration?
RAPID distribution and RAPID redistribution
