Prop, Etomidate, Ketamine Flashcards
(105 cards)
1
Q
Is Propofol soluble or insoluble in the blood?
A
Insoluble
2
Q
What do we add to propofol? What is the concern with one of the components?
A
10% soybean oil
- 25% glycerol
- 2% egg lecithin
Egg lecithin is related to allergy
3
Q
Is propofol chiral?
A
No
4
Q
What is propofol’s pain on injection related to?
A
the phenol group
5
Q
Name two ways you can prevent pain on injection with Propofol.
A
Large bore IV in AC
administer with lidocaine
6
Q
What is the antagonist to propofol?
A
there isn’t one! the only way for it to stop working is for it to wear off
7
Q
What is the most important advantage to propofol?
A
rapid return to consciousness with minimal residual effects
8
Q
What is the difference between Diprivan and Propofol?
A
Diprivan is made in the U.S. and doesn’t have sulfites. pH 7-8.5. Contains 0.05% EDTA
Propofol is made in other countries and has sulfites. pH 4.5-6.4. Contains 0.025% sodium metabisulfite or benzyl alcohol
9
Q
If you have an asthmatic patient and have to use this drug, which suspension should you use - Diprivan or Propofol?
A
Diprivan. No sulfites which are detrimental to asthmatics
10
Q
Is propofol an acid or a base? What is the pKa?
A
Acid. pKa 11
11
Q
What receptor does propofol act on?
A
GABA - A
12
Q
Is propofol an antagonist?
A
No!
13
Q
You are doing a spinal case and the surgeon tells you he needs to assess spinal motor neurons throughout the procedure. Would propofol be an appropriate agent?
A
Yes - spinal motor neuron excitability not altered (benefit over gases that have 3 A’s)
14
Q
Which other neurotransmitter is affected by propofol to a lesser extent?
A
Glycine
15
Q
Does propofol undergo first pass?
A
Yes - tissue uptake in the lungs
16
Q
How is propofol metabolized?
A
Extensive hepatic metabolism by CYP450
17
Q
Phase I or Phase II metabolism of Prop?
A
Phase II glucuronidation
18
Q
What is the effect time of propofol?
A
4-6 minutes - redistribution
19
Q
What is the half-life of propofol?
A
11 hours (r/t active metabolite)
20
Q
What is propofol’s active metabolite?
A
4-hydroxypropofol
21
Q
Context sensitive half time?
A
less than 40 minutes
22
Q
Is propofol appropriate for a patient with hepatic or renal dysfunction?
A
Yes! Not influenced by hepatic or renal dysfunction, can be given with cirrhosis/ESRD
23
Q
What is a consideration with propofol for patients over 60 years old?
A
decreased rate of plasma clearance
24
Q
What does propofol bind reversibly with? To what extent?
A
erythrocytes and plasma proteins (50%)
plasma albumin (48%)
free (2%)
25
On the plasma concentration curve, would the effect time of propofol be related to the alpha or beta phase?
Alpha - propofol's effect time is related to re-distribution in single bolus dose
26
You have propofol circulating in the plasma, is it producing an effect?
Maybe, maybe not. Know that just because it's in the plasma, it may be bound to proteins and cannot exert an effect.
27
Increased free fraction of propofol would be associated with which patients?
Patients with severe hepatic/renal disease
pregnancy
elderly
28
If your hepatic blood flow is terrible, how will that effect the metabolism of propofol?
It won't! Clearance exceeds hepatic blood flow. Enzymes will cause glucuronidation regardless of hepatic blood flow to metabolize
29
What is an ideal property of propofol?
Rapid and pleasant loss and return to consciousness
30
You gave propofol and your patient starts twitching. Is it likely a seizure?
No. Propofol may induce myoclonus secondary to disinhibition of subcortical centers (but less so than etomidate)
more so in younger patients
31
Is propofol a good drug for neuro patients?
Yes - neuroprotectant effects*
32
What are the CV effects of propofol?
decrease in sympathetic tone and vasodilation
cardiac and baroreceptor depression
significant effect on SVR
33
Will propofol cause respiratory depression?
YES. If you give it in sufficient doses, almost everyone will stop breathing**
r/t decreased sensitivity of respiratory center to CO2
34
Your patient is having a bronchospasm. Which drug may be useful?
propofol! it causes minimal bronchodilation
35
Induction dose of prop? Which patients should you adjust this for?
1.5-2.5 mg/kg IV
decrease in elderly
increase in pediatrics
36
You have an elderly patient coming in for a total knee arthroplasty. The case takes 1-3 hours. You don't want to expose them to gas and opioids for that long. What would be a better technique?
Regional for analgesia and areflexia, propofol for amnesia
37
You have a patient coming in for an endoscopy. What would be an appropriate drug and IV sedation dose?
Propofol - prompt recovery without residual sedation
| 25-100 mcg/kg/min
38
Which of the 3 A's does propofol cause?
Amnesia only
| no analgesic properties**
39
Can propofol be used with an anxiolytic or opioid?
Yes
40
Your patient tells you they had severe post op N&V after their last surgery. Is prop appropriate?
Yes - anti-nausea properties
41
Maintenance of anesthesia dose for prop? what should it be used with?
100-300 mcg/kg/min
| short-acting opioid
42
Antiemetic dose of prop?
10-15 mg IV followed by 10 mcg/kg/min infusion
43
Antipruritic dose of prop?
10mg IV
44
Anticonvulsant dose of prop?
1 mg/kg IV
45
What type of pain can propofol be effective for?
Minimal to no analgesic effects, but may be beneficial with neuropathic pain
46
Lecithin allergy is associated with what drug? what foods can it be found in?
Propofol. Eggs**, peanuts, soybean
47
What are risk factors for PRIS?
> 4mg/kg/hr (66mcg/kg/min) for greater than 48h, critical illness, high fat low carb intake, concomitant catecholamine infusion, steroid administration, inborn errors of mitochondrial fatty acid oxidation
48
Your patient goes into DKA or rhabdo. What is happening?
PRIS
49
Your patient has a high anion gap metabolic acidosis. What is happening?
PRIS
50
Signs of PRIS?
High anion gap metabolic acidosis (DKA, rhabdo), cardiac failure, persistent brady refractory to treatment, fever, severe hepatic and renal disturbances
51
CV Clinical features of PRIS
hypotension, bradycardia, ischemic EKG, V tach, V fib, arrhythmias, wide QRS, asystole, HF
52
Respiratory features of PRIS
hypoxia, pulmonary edema
53
Renal features of PRIS
AKI, hyperkalemia
54
Musculoskeletal features of PRIS
Rhabdo
55
Metabolic features of PRIS
hyperthermia, high AG metabolic acidosis, urine discoloration
56
Hepatic features of PRIS
Hepatomegaly, abnormal LFTs, steatosis, lipidemia, hypertriglyceridemia
57
Is propofol addictive?
Yes - wellbeing on emergence and tolerance buildup
58
When might etomidate be considered for induction for your patient over propofol?
Cardiac patient - stable BP and HR with etomidate
59
Is etomidate lipophilic or water soluble?
water soluble in acidic pH, lipophilic at physiologic pH. pH 8.1, pKa 4.2 , base.
60
Which is chiral, propofol or etomidate?
etomidate
61
Which receptors does etomidate work on?
GABA-A
62
Which drug (etomidate or propofol) has more free drug? What does this affect?
Etomidate (25%) vs. 2%. More free drug = more risk for adverse effects
63
What process is responsible for metabolism of etomidate?
Hydrolysis. plasma esterases and microsomal enzymes in the liver
64
Name 3 drugs that cause myoclonus.
Etomidate, Methohexital, Clonazepam.
65
How long is return to consciousness with etomidate?
5-15 minutes
66
What are the neurologic effects of etomidate?
Decrease in CMRO2 and CBF. Decrease in ICP while maintaining CPP. Some cerebral protection
67
If you administer etomidate or propofol, with which drug would you expect to see less spontaneous breathing?
Propofol
| greater % of patients will breathe with induction doses of etomidate
68
You give an induction dose of 0.45 mg/kg of etomidate for a cardiac patient. Is this appropriate?
No. Doses > 0.45 mg/kg result in decreased BP and CO. Appropriate induction dose 0.2-0.4mg/kg IV
69
Is etomidate a good choice to treat pain?
No. No analgesia
70
Does etomidate cause pain on injection?
Yes. Burns. Minimal.
71
What is a side effect of etomidate that is unique to this drug?
Adrenocortical suppression, more commonly in critically ill, septic patients
72
What is the enzyme that converts cholesterol to cortisol? Which drug inhibits this?
11B hydroxylase enzyme
| Etomidate
73
what is the allergic incidence with etomidate?
low!
74
Which drug is characterized by the patient's eyes remaining open and a slow nystagmus gaze
Ketamine "dissociative anesthesia"
75
Which of the 3 A's does ketamine produce?
Amnesia and Analgesia
76
Rank the 3 drugs from most to least bound to plasma proteins.
propofol (98%), etomidate (75%), ketamine (12%)
77
Rank propofol, etomidate, and ketamine from highest to lowest lipid solubility.
Highest is propofol, then etomidate, then ketamine
78
How is ketamine metabolized?
demethyjation by CYP450 micro enzymes
79
How is ketamine metabolized?
demethyation by CYP450 micro enzymes
80
Does ketamine cause respiratory depression?
No
81
What lipid vehicle is ketamine mixed with for injection?
No lipid vehicle for dissolution. No pain on injection
82
Which drug has metabolism that is dependent on hepatic blood flow? Which has metabolism that exceeds hepatic blood flow?
dependent - ketamine
| exceeds - prop
83
Onset and half life of ketamine?
Onset 15-30 minutes
| elimination half life 2-3 h
84
Which other receptors can ketamine act on?
muscarinic, monoaminergic, opioid, nicotinic acetylcholine, voltage sensitive sodium, L-type calcium, some GABA
85
How does ketamine exert its analgesic effects?
Direct inhibition of cytokines
86
Which drug has an increased risk for laryngospasm/bronchospasm? Which drug is a used to treat this?
Ketamine (increased salivary secretions). Propofol.
87
Which drug would be inappropriate for a neuro patient, a patient having cataract surgery, or a patient with CAD?
Ketamine
- Increased CBF, CMRO2, ICP
- Increased intraocular pressure
- Increased BP and HR
88
What do you have to give ketamine with? What is the best agent?
A benzo - hallucinations otherwise.
| Midazolam
89
Which drug is best for trauma or hypovolemic patients?
Ketamine
90
What are the IV, IM, and oral doses for ketamine?
1-2.5mg/kg
4-8mg/kg IM
10 mg/kg PO
91
True or False: the best time to give Ketamine is 10 minutes prior to surgery. Why or why not?
False. Less of an effect than if given at start of surgery when pain starts and receptors are more reactive
92
What is the dose of Ketamine for analgesic effects?
0.2-0.5mg/kg
93
Is Ketamine more effective on somatic or visceral pain?
Somatic
94
Is Ketamine appropriate in an OB case?
Yes. OB anesthesia without neonatal depression, compromised uterine tone, BF, or neonatal status
95
Is Ketamine better for acute or chronic pain?
Chronic
96
What is the indication for the ketamine dart?
good for pediatric patients with asthma
97
What would be the benefit of giving sub anesthetic doses of ketamine with propofol?
Ketamine gives you the analgesic properties and combined with prop it stabilizes hemodynamics and avoids unwanted emergence reactions
98
What can you give to patients who are at risk for increased ICP prior to giving ketamine?
Thiopental, Benzo
99
What is the effect if you administer ketamine with succ?
Apnea prolonged after administration of succ due to inhibition of plasma cholinesterase
100
What is Ketamine's effect with NMBDs?
Enhancement of their effects
101
How long after administration of Ketamine can emergence delirium occur?
24 hours
102
Risk factors for emergence delirium with Ketamine?
Age > 15, female, history of personality problems, frequent dreams
103
What is the effect if you give atropine with ketamine?
Increased risk of emergence delirium
104
Propofol Half time (h), Vd (L/kg), Cl (mL/kg/min)
0.5-1.5h
2.5-3.5 L/kg
30-60 mL/kg/min
105
Etomidate half time (h), Vd (L/kg), Cl (mL/kg/min)
2-5 h
2.2-4.5L/kg
10-20 mL/kg/min
