Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

*Pharmacology > Apex- Volatile Anesthetics-pharmacokinetics > Flashcards

Apex- Volatile Anesthetics-pharmacokinetics Flashcards

1
Q

Which Anesthetic is shown?

A

Sevo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Inhaled anesthetic are categorized into what 3 groups?

A

Ethers (R-O-R) —> iso, sevo, des,
Alkanes (R-H) —> H for halothane, cHloroform
Gases —> Nitrous oxide, cyclopropane, xenon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which gases have chiral carbons and which do not?

A

Chiral carbons : Des & ISO

No: Sevo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At ATM pressure and room temp, which type of inhaled anesthetic will exist as liquids? (Ethers, alkanes, gases)

A

Ethers and Alkanes (Gases exist in gaseous form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Out of Ethers, alkanes, and gases, which have a characteristic “C-O-C”

A

Ethers

“Ether Bridge” = “C-O-C”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the addition of a heavier chlorine atom do? Which gas has this?

A

ISO - increases POTENCY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

If full fluorination decreases potency, why is sevo 3x more potent than DES?

A

Likely due to the propyl side chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 2 classes of ethers? Examples?

A

Methyl-isopropyl-ether (Sevo)

Methyl-ethyl-ether (ISO & Des)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Does halogen have an ether bond?

A

No, It’s a halogenated hydrocarbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What has a bromine atom?

A

Halogenated agents (Halothane, chloroform)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many fluorines does ISO have? What else is characteristic to ISO?

A

5 flurines & 1 chlorine “Cl” atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many flurines does Sevo have?

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many flurines does Des have?

A

6 “Fully flurinated”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

1-Chloror, 2, 2, 2 - Trifluroethyl difluromethyl ether

A

Isoflurane

Trifluro = 3
+ difluro = 2
5 flurines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fluromethyl, 2, 2, 2 - Trifluro-1- (Trifluromethyl) ethyl ether

A

Sevo

Flur = 1
+ trifluro = 3
+ trifluro = 3
= 7 flurines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How much more potent is ISO than sevo and Des

A

X2 more than sevo

5x more than Des

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Difluromethyl 1, 2, 2, 2 Tetrafluroethyl ether

A

Des

Difluro = 2
+Tetrafluro =4
=6 flurines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What chemical structure?

A

Des

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

2-Bromo-2-Chloro-1,1,1, Trifluroethane

A

Halothane
1. bc of Bromo
& 2 - Trifluro-> has 3 flurines
& lacks an ether bridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What 2 things are capable of transforming volatile anesthetic into toxic compounds?

A

CO2 absorbent and the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which agent is unstable, even in the presence of hydrated soda lime?

A

Sevo (Compound A; minimal FGF requirements)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What agent(s) can become unstable in desiccated soda lime and produce carbon monoxide?

A

ISO and Des (Des>ISO bc DES is the devil)

Sevo is unstable in hydrated soda lime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Vapor pressure of Sevo

A

157

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Vapor pressure of Des

A

666

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Vapor pressure of ISO
238 (240)
26
Vapor pressure of N20
38,770
27
Boiling point of Sevo
59 C
28
Boiling point of Des
23 C(25) | 2*3 =6
29
Boiling point of ISO
49 C(50)
30
Boiling point of N20
-88 C
31
Molecular weight of Sevo
200g/mol
32
Molecular weight of Des
168g/mol
33
Molecular weight of ISO
184g/mol(186- flip 168 for des to 186 for iso)
34
Molecular weight of N20
44g/mol
35
Which inhalational agent has preservatives
None
36
Which inhalational agent is stable in dehydrated CO2 absorbent?
N20
37
Toxic byproduct of each inhalational agent
Sevo. Compound A ISO & Des - carbon monoxide (Des>ISO) (in desiccated soda lime) N20 - none
38
Vapor pressure is (directly/inversely) proportional to temperature
Directly | Increased Temp = increased VP
39
At high altitude, a liquid will boil ad higher or lower temperatures?
Lower due to lower atmospheric pressures
40
The pressure exerted by a vapor in equilibrium with its liquid or solid phase inside a closed container
Vapor pressure
41
The fractional amount of pressure that a single gas exerts within a gas mixture What law?
Partial pressure -Dalton’s law
42
Total gas pressure in a container = the sum of all the partial pressures exerted by each gas (What law)
Dalton’s | P1 + P2 + P3 = Total P
43
What is volume% ?
What you set your dial to
44
What is the depth of anesthesia determined by?
The PARTIAL PRESSURE of an anesthetic agent in the brain (NOT volume%)
45
High altitude may lead to underdosing of which agent and why?
Desflurane - bc the conventional variable bypass vaporizer automatically compensates for elevation but the Tec6 does not
46
6% of Desflurane at sea level results in a partial pressure of what?
45. 6 | 0. 06 x 760
47
6% of Des in Denver (1 mile above sea level) results in a delivered partial pressure of what?
37. 2 | 0. 06 x 620mmHg
48
How does full fluorination affect Des’s PK/PD profile? (3)
Decreased potency Increased vapor pressure Increased resistance to biotransformation
49
P total = P1 + P2 + P3
Dalton’s Law
50
Blood: Gas partition coefficient of Sevo, ISO, Des, N20
ISO- 1.43 (I love you, I love ISO - most potent love) Sevo- 0.69 (next comes the middle man with 69) N20 - 0.47 Des - 0.42 (4+2 = 6 = des the devil who lives in hell so he’s at the bottom)
51
What describes the ability of an anesthetic agent to dissolve into the blood and tissues?
Solubility (B:G coefficient)
52
Anesthetic dissolved in blood/Anesthetic inside alveolus =
Blood:Gas partition coefficient
53
Who’s law describes the solubility of gases in a solution?
Henrys
54
The speed of induction is a function of what property of the agent?
Solubility - low solubility = less uptake into the blood = faster rate of rise (of pressure in the alveoli/brain) - faster onset - high solubility = more uptake into the blood = slower rate of rise (less pressure able to build in the alveoli/brain) - slower onset
55
The main objective when administering volatile anesthetic is to produce a state of anesthesia by building up a partial pressure of the agent where?
Inside the patient’s brain and spinal cord
56
What is FA/FI
``` FA = the partial pressure of anesthetic in the Alveoli FI = the concentration leaving the vaporizer ```
57
Which agents go where on the FA/FI curve?
Nitrous Oxide (0.47) Desflurane (0.42) Sevo (0.69) ISO (1.43)
58
What 3 factors determine anesthetic uptake into the blood?
1. Agent solubility 2. Partial pressure difference between alveoli and blood 3. Cardiac output
59
Low solubility = (slower/faster) onset | High solubility = (slower/faster) onset
Low solubility = faster onset (less taken up by blood, more pressure in the alveoli/brain) High solubility = slower onset (more taken up by blood, less pressure in the alveoli/brain)
60
Why is the rate of rise of FA/FI faster for N20 then DES when des has a lower B:G coefficient?
Bc of the concentrating effect… sure… | Faster “wash-in”….
61
What does FI stand for?
Inspired fraction of anesthetic (carried by the FGF - increased FGF = increased total amount carried)
62
FA
Alveolar concentration of anesthesia
63
2 main ways to increase FA/FI
Increase wash-in : high fresh gas flow, high alveolar ventilation, low FRC, low time constant, low anatomic dead space Decrease uptake: low solubility, low CO, low Pa-Pv difference
64
Hepatic Biotransfomration of Des, ISO, sevo, halothane, nitrous
Rule of 2s! (D-I-S) Des- 0.02% Iso- 0.2% Sevo 2% - 5% Halothane - up to 20% Nitrous = 0.004 (2 zeroes + (2+2=4) - essentially not metabolized in the body
65
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low Pa-Pv difference
Decreases uptake
66
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High anatomic dead space
Decreases wash-in
67
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High FGF
Increases wash-in
68
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High agent solubility
Increases uptake
69
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High FRC
Decreases wash-in
70
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High Cardiac output
Increases uptake
71
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low time constant
Increases wash-in
72
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low FGF
Decreases wash-in
73
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low agent solubility
Decreases uptake
74
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High Pa-Pv difference
Increases uptake
75
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: High alveolar ventilation
Increases wash-in
76
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low FRC
increases wash-in
77
Increases wash-in; Decreases wash-in; Increases uptake; Decreases uptake: Low CO
Decreases uptake (which increases FA/FI)
78
What does the Vessel Rich Group consist of? (5)
Brain, heart, liver, kidneys, endocrine organs
79
``` Cardiac output vs Body mass % of VRG Muscle & Skin Fat VPG (tendons, ligaments, cartilage, bone ```
80
In what 2 ways are inhaled anesthetic eliminated from the body?
1. Alveoli (primary) | 2. Hepatic biotransformation (secondary)
81
Important metabolites and associated risks of Des, ISO, sevo
Des & Iso > Trifluoroacetic acid > small risk of immune-mediated hepatic dysfunction Sevo > free fluoride ions > theoretical risk of high output kidney failure
82
What is the mechanism for halothane hepatitis?
High concentration of TFA (trifluroacetic acid) in the liver)
83
What is characteristic of high output renal failure from sevo related to free fluoride ion production?
Unresponsiveness vasopressin | Polyuria, hypernatremia, hyperosmolarity, increased creat, inability to concentrate urine
84
What toxic compounds from inhalational anesthetic are produced inside vs outside the body
Produced inside the body: TFA & free fluoride ions | Produced outside the body: Carbon monoxide (exposure to desiccated soda lime with iso and des)
85
FDA guidelines regarding the minimum FGF you should use with sevo
FGF of 1L/min for up to 2-MAC hours FGF of 2L/min after 2-MAC hours 2% sevo (1MAC) x 1 hour = 1 Mac hour 1% sevo (1/2 MAC) x 2 hours = 1 MAC hour 2% sevo (1 MAC) x 2 hours = 2 Mac hours 1% sevo (1/2 MAC) x 4 Mac hours = 2 MAC hours
86
Which P450 enzyme is chiefly responsible for halogenated anesthetic metabolism in the liver?
CYP 2E1
87
The higher the concentration of inhalation anesthetic delivered to the alveolus (FA), the faster its onset of action — term x 2
``` Concentration effect (not concentrating) Or over-pressurizing ```
88
When a patient is breathing in room air, what is the primary gas being inhaled?
Nitrogen (78%)
89
How much more soluble is nitrous oxide in the blood compared to nitrogen (in room air)
34x more soluble
90
Explain the concentratING effect
Bc nitrous oxide is 34x more soluble in blood than nitrogen, when it is introduced into the lung, >the volume of n20 going from the alveolus > pulmonary blood is much higher than the amount of nitrogen moving in the opposite direction (pulm blood > alveolus) >this causes the alveolus to shrink, and the reduction in alveolar volume causes a relative increase in FA (Explains why nitrous and not des achieves the fastest rate of rise of FA/FI)
91
How does the 2nd gas effect work?
Bc nitrous oxide is 34x more soluble in blood than nitrogen, when it is introduced into the lung, >the volume of n20 going from the alveolus > pulmonary blood is much higher than the amount of nitrogen moving in the opposite direction (pulm blood > alveolus) >this causes the alveolus to shrink, and the reduction in alveolar volume causes a relative increase in FA of N20 (Concentrating effect) >then you have reduced alveolar volume + augmented tracheal inflow with a second gas to replace that shrunken, nitrous filled alveolus, causing a relative increase in concentration of the 2nd gas (increased pressure bc of smaller alveoli ) — i could be making that up
92
Gas containing areas of the body can absorb up to __L of N20 within 2 hours
30L
93
Explain diffusion hypoxia - how can you prevent it?
So 30L of N20 can be absorbed into gas containing areas of the body within 2 hours >when this massive amount of N20 is transferred out of the body and into the alveoli to be exhaled, it dilutes alveolar concentrations of o2 & CO2 >causing a temporary diffusion hypoxia and hypocarbia (decreased stimulus to breathe) -> can decrease PaO2 further Prevent if by administering 100% FIO2 for 3-5 minutes after nitrous has been discontinued
94
The rate of rise of FA/FI of which agent will be affected the most with a right to left shunt
Desflurane
95
How does the concentration effect affect the rate of rise on the FA/FI curve?
The higher the concentration of inhalational anesthetic delivered to the alveolus, the faster its onset of action
96
Jeopardy style: Changes in alveolar ventilation affect the rate of rise of FA/FI
What is: Ventilation effect
97
Does the second gas effect have a more meaningful impact on iso or sevo? Why?
Iso bc of it’s higher blood:gas solubility | Iso>sevo>des
98
A right to left cardiac shunt (slows/speeds) induction with a volatile agent.
Slows (some blood isn’t going to the lungs to pick up the inhalational agent in the lungs + dilutes the blood that did pick up the inhalational agent)
99
Inhalational induction is slower with volatile agents in pts with right to left shunts. Agents with (low/high) solubility are affected the most & agents with (low/high) solubility are affected the least
Low solubility affected the most (des) (likes to stay in lungs and the blood is bypassing them- will notice the greatest impact with these agents) High solubility affected the least - wont notice as big of a difference, will still take long
100
Right to-left shunt: (slower/faster) induction with IV agents
Faster (bypasses the lungs goes right to systemic)
101
Left-to-Right shunt: (faster/slower) induction with IV agents
Slower (keeps going back to right side and not out to systemic)
102
T/F: in patients with a left-to-right shunt, there is no meaningful impact on induction with a volatile anesthetic
True
103
5 Examples of Right to Left shunts
“To the left, to the left — move your FEETT” Foremen ovale Eisenmenger’s Syndrome (think Alexa Eisen is Right winged, R>L shunt Ebstein’s anomaly (Think Alexa eisen, conspiracy theorist like the rest of us, Epstein conspiracy) Tetralogy of fallot Tricuspid atresia
104
The blood:gas partition coefficient MOST closely correlates with: speed of emergence, vapor pressure, biotransformation, potency
Speed of emergence
105
What partition coefficient is related to potency
Oil:Gas
106
Potency is (directly/inversely) proportional to MAC
Inversely -decreased potency, higher MAC (takes more to achieve Mac)
107
Which anesthetic agent undergoes the GREATEST degree of elimination from the lungs?
Desflurane >the greater amount of agent metabolized by the liver, the less is eliminated from the lung >des undergoes the least metabolism from the liver (0.02%), so it’s elimination from the lung is the greatest
108
Which anesthetic agents bear the closest chemical resemblance?
Iso & Des | Iso has a chlorine molecule and des has a fluorine instead
109
What occurs when a liquid’s vapor pressure equals atmospheric pressure?
Boiling
110
Oil:Gas coefficient of Sevo, Des, Iso
ISO 100 Sevo 50 Des 20

*Pharmacology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions