IA #1 Flashcards

(70 cards)

1
Q

How are IA eliminated?

A

Via the lungs (exhaled)

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2
Q

What effects does aging have on CO?

A

Decreased

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3
Q

Boyles law says that _ and _ have an inverse relationship

A

Volume and pressure

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4
Q

Fick’s law of diffusion says that diffusion of the gas into the blood depends on: (3 things)

A

The thickness of the membrane
The partial pressure of the gas
The solubility of the gas (highly soluble in the blood means it wants to get into the blood and prefers to stay there)

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5
Q

Graham’s Law of effusion says that gas molecules will effuse through a ___ or ____.

A

Channel or pore.
The smaller the molecule the easier it will effuse to the other side. But this is all dependent on solubility. CO2 is more water soluble than O2 so it is more diffusable.

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6
Q

What 3 pressures are in equilibrium when the patient is asleep in the maintenance phase?

A

PA, Pa, Pbrain

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7
Q

Alveolar pressure represents what 2 things?

A

The depth of the anesthetic and where the pt is in recovery from the anesthetic

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8
Q

There are 3 partial pressures we are concerned with. What are they?

A

Ventilator to lungs
Lungs to blood
Blood to tissue

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9
Q

How does a high or low CO affect induction?

A

Low: Slow induction
High: Fast induction

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10
Q

How does the A-V partial pressure difference affect diffusion of the gas?

A

Explain :) long story

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11
Q

Alveoli to blood depends on what coefficient?

A

Blood: gas partition coefficient

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12
Q

Arterial blood to brain depends on what coefficient?

A

Brain: blood partition coefficient

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13
Q

What does a high blood: gas partition coefficient mean?

A

The gas would rather stay in the blood than diffuse into the tissues

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14
Q

What does an Fe/Fi ratio of 1 mean?

A

Equilibrium. What is going in is coming out

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15
Q

What does the Fe/Fi ratio mean?

A

The concentration of what goes into the lungs vis what comes out the lungs

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16
Q

The concentration effect depicts the impact of the Pi on the rate of rise of the ___

A

PA

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17
Q

The higher the PI of the volatile that is administered, the more rapidly PA approaches ____

A

Pi

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18
Q

Over-pressurization means you are administering a high concentration of the gas (therefore higher partial pressure) so PA will approach ____ more rapidly. The goal is for PA to equal Pi because that means the concentration delivered is what the patient is actually getting.

A

Pi

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19
Q

Sevo’s MAC is 1.8% If you have at 7%, what does that mean?

A

Over pressurized. The Partial pressure of gas will be higher

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20
Q

Second gas effect means that if NO (diffuses very easily) is given with a volatile, the NO will diffuse across faster leaving the volatile behind and create a ___

A

Big concentration gradient, the gas will now get forced into the blood

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21
Q

Nitrous oxide diffuses into air-filled cavities with both _ and _ walls

A

Compliant and noncompliant

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22
Q

How much air diffuses into air-filled cavities in 10-15 minutes?

A

10 L

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23
Q

Generally speaking, we would not give NO to pt’s undergoing which procedures?

A

Belly, ear, eye, or if they have an existing pneumo (will make it worse)

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24
Q

Induction of anesthesia happens when Pi is equal to P_

A

A

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25
How does increased alveolar ventilation (by increasing the rate not tidal volume) increase the rate of anesthesia induction? BUT
The quantity of the gas pt is taking in is higher --> The PA will equilibrate with the Pi much faster BUT the increased ventilation leads to a dilution of CO2. Low CO2 leads to constriction of cerebral blood vessels. Less cerebral blood flow leading to less gas getting to the brain where it should be to work!!!
26
What is the bodies safe guard when we take in too much IA?
The IA works directly on medullary center (dose dependent) and will slow rate of breathing when dose is high. The decreased rate decreases alveolar ventilation which will decrease the amount of gas we are taking in to help decrease the PA :)
27
If the body decreases its RR because too much IA, concentration in the brain will decrease because the PA is low now. That is a shift from _. As the PBrain decreases what happens to the RR? Does this happen with MV?
P brain to PA Increases No
28
Solubility is a RATIO of how the inhaled gas distributes between 2 compartments at _ when pressures are _
equilibrium equal
29
What is the relative capacity of each compartment to hold a volatile?
Solubility
30
Solubility is dependent on temperature. If the temp of the blood increases, solubility increases or decreases?
Decreases
31
If the temp of the blood decreases, solubility increases or decreases?
Increases
32
If blood solubility is low, is induction prolonged or rapid?
Rapid
33
If blood solubility is high, is induction prolonged or rapid?
Prolonged
34
What is the Blood:Gas partition coefficient of Halothane
2.54
35
What is the Blood:Gas partition coefficient of Enthrane
1.9
36
What is the Blood:Gas partition coefficient of Isoflurane
1.46
37
What is the Blood:Gas partition coefficient of NO
0.46
38
What is the Blood:GAs partition coefficient of Desflurane?
0.42
39
What is the Blood:Gas partition coefficient of Sevoflurane?
0.69
40
IA are not highly soluble in the brain. What does that mean?
They do not want to stay there! As soon as the pressure gradient shifts Pbrain > PA, the gas will start to leave
41
When you shut the gas off, the Pa and PBrain were at equillibrium, but fat was not. Where does that shift things?
From brain to muscle and fat. Then will have to come out the same way to be breathed out
42
Why do you wake up slower with the gases that took longer to get you to sleep?
Once they move from brain to blood they still do not want to leave blood to get back into the alveoli to be exhaled
43
List the recovery time of the gases from longest to shortest
Longest, Halothane Isoflurane Sevoflurane Shortest, Desflurane
44
What is considered a measure of potency?
MAC
45
What is MAC awake?
0.3 to 0.5
46
What is MAC BAR?
1.7 to 2
47
What is the MAC value of Sevoflurane?
1.8 %
48
What is the MAC value of Desflurane?
6.6%
49
What is the MAC value of NO?
104%
50
What is the MAC value of Isoflurane?
1.17%
51
What is the MAC value of Enflurane?
1.63%
52
What is the MAC value of Halothane?
0.75 %
53
MAC peaks at what age?
1 y/o
54
How much does MAC % decrease per decade?
6%
55
What are the 2 biggest factors that affect MAC?
Body temp and age
56
What are the 4 things that increase MAC?
Hyperthermia Hypernatremia Drug-induced increase in catecholamine levels Red heads (excess pheomelanin levels)
57
What are the 11 things that decrease MAC?
Hypothermia Hyponatremia Lidocaine pre op meds with intra op opioid Alpha 2 agonists Acute ETOH ingestion Pregnancy S/P birth (12-72 hours) ECMO pre op meds with intra op opioid PaO2 <38 mmHg MAP < 40 mmHg
58
How do IA cause spinal immobility?
Depress glutamate-R (AMPA and NMDA) Enhance glycine Block Na channels to block release of glutamate
59
How do IA cause LOC?
Increase GABA in the brain Increase glycine
60
What is Daltons law?
Sum of total pressures
61
What is vapor pressure?
Pressure at which pressure of the vapor and liquid are at equilibrium
62
What is Henry;s law?
The amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid
63
What do heat and cold do to vapor pressure?
Hot: increase Cold: decrease
64
The greater the vapor pressure, the more likely the gas is to _
Evaporate
65
What is the vapor pressure of Halothane?
243
66
What is the vapor pressure of Enflurane?
175
67
What is the vapor pressure of Iso?
238
68
What is the vapor pressure of Des?
669
69
What is the vapor pressure of Sevo?
157
70
Vaporizers change liquid to ____
Vapor