Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

SRNAProfessionalGuide II > Anesthesia Vaporizers > Flashcards

Anesthesia Vaporizers Flashcards

1
Q

Vapor Pressure (VP)

A

Created by molecules in the vapor phase bombarding the walls of a container

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

Saturated Vapor Pressure (SVP)

A

Gas phase above the liquid usually at 20C

Increase Temp –> Increase SVP

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

VP is independent of

A

atmospheric pressure if the temperature remains constant

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

Boiling Point

A

The temperature at which the vapor pressure equals atmospheric pressure

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

Units of Vapor Concentration

A 
Absolute pressure (mmHg) 
Volumes percent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Volumes Percent is volume of vapor per 100 volumes of

A

total gas the partial pressure due to vapor/total ambient pressure X 100%

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

Dalton’s Law of Partial Pressures

A

The total pressure exerted by a gas mixture is the sum of the individual pressures of its constituents

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

Latent Heat of Vaporization

A

The # of cal required to change 1 g of liquid into vapor without a temp change.

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

Specific Heat

A

The # of cal required to increase the temp of 1 g of a substance by 1 deg C

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

Dalton’s Law of partial pressure summary

A

In a mixture of gasses the pressure exerted by each gas is the same as that which it would exert if it alone occupied the container.

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

Diffusion Can take place

A
  • thru membrane
  • thru gas/liquid interface
  • between gasses
  • between liquids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Application of Fick’s Law

A

Oxygen diffuses in
CO2 diffuses out
Diffusion respiration - pre-oxygenation and emergencies

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

Henry’s Law

A

At a gas/liquid interface, some of the gas will dissolve in the liquid.

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

Relative amount dissolved in solvent depends on the

A

chemical nature of the gas and solvent

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

Molecules of the gas within the liquid will exert

A

the same amount of pressure as the molecules overlying the liquid (at equilibrium)

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

PP will the same, but the number of molecules needed to exert the pressure depends on

A

the gas and solvent

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

Effect of pressure

A

As pressure of gas overlying liquid increases, pressure of gas in liquid and number of molecules of the gas increase proportionally

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

Temperature must be named in anesthesia,

A

37 degrees is used

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

blood:

A

gas most important

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

gas:

A

oil is next most important

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

Solubility Coefficient

A

Ostwald - the volume of gas which dissolves in one unit volume of the liquid at the temperature concerned
Useful in anesthesia

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

Does the Oswald solubility coefficient dependent on pressure

A

Independent of pressure

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

Vaporizers: Measured Flow

A

Copper Kettle, Vernitrol

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

Vaporizers: Variable Bypass

A

Ohmeda Tec 4 & 5, Drager 19.1, 19.3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Vaporizers: Blender
Ohmeda Tec 6 (Desflurane)
26
What happens to SVP with increased temperature?
More in the vapor phase
27
Difference MEASURED FLOW (COMM)
``` Carrier gas (CG) bubbles through agent Manual Temp. conversion Multi-agent Operator determines CG split No longer manufactured (but still present on field machines) ```
28
Different Variable Bypass | CH - AAA
``` CG flows over agent Auto adjust for Temp & Pressure Agent specific Auto CG split Higher safety standards ```
29
Decrease Temperature--> Decrease Vapor Pressure
Sluggish/not hitting the sides of the vaporizer | More flow must go through the vaporizing chamber so that the patient receives the same concentration of agent
30
As liquid is vaporized energy is lost in the form of
Heat
31
Increase Temperature--> Increase Vapor Pressure
Hitting the sides of the vaporizer rapidly | Less flow must go through the vaporizing chamber so that the patient receives the same concentration of agent
32
Increase temp will______vapor pressure
Increase
33
TEC 6
``` No Output Alarm Agent < 20 ml (1 bar) Tilt > 10 degrees Power Failure Internal malfunction Low Agent Illuminates with 50cc of agent Warm-Up 10 minutes to reach operating temp of 39C ```
34
Why a different vaporizer for Desflurane?
Requires an external heat source - 4-9 times more Des is required than other IA - Absolute amount of Des vaporized is much higher than other IA which would cause excessive cooling - Traditional vaporizers could not compensate adequately
35
Traditional vaporizer would cause an
anesthetic overdose Des = 735 ml/min opposed to Iso = 47 ml/min
36
VP of Desflurane
VP of 669 mmHg – near 1 atm
37
Working pressure is affected by
FGF and viscosity of the carrier gases
38
Increase in FGF increase
vapor flow as well
39
Factors That InfluenceTec 6 Vaporizer Output
Varied Altitudes | Carrier Gas Composition
40
Tec 6 – Effects of Varied Altitudes
Requires manual adjustments of the concentration dial with changes in barometric pressure - - It is a pressurized vaporizer - --It works at an absolute pressure - ---Partial pressure of Des changes with changes in ambient pressure
41
Required setting =
Normal setting (%) X 760 mmHg /ambient pressure (mm Hg)
42
Tec 6 – Carrier Gas Composition
- Decreased concentration output can occur with low flows of gases other than oxygen due to changes in viscosity Vaporizer output is 20% less with nitrous than with oxygen - Nitrous oxide is less viscous than oxygen resulting in a lower working pressure at the differential pressure transducer - Take home – May have to increase dialed concentration with low flow anesthesia - Careful with low FIO2
43
Variable Bypass Vaporizers -
Varied Altitudes and the effects on agent output
44
***HypoBaric take home
The high resistance pathway through the vaporizing chamber offers less resistance thereby increasing vaporizer output. Decrease Barometric Pressure --> INCREASED Vapor administered = Give more vapor than you have dialed on the vaporizer Opposite of changes in temperature
45
***HYPERBARIC TAKE Home
Changes in the density of vapors/gases cause more resistance to flow through the vaporizing chamber and a decrease in vaporizer output INCREASE Barometric Pressure -->DECREASED Vapor administered = Give less vapor than you have dialed on the vaporizer
46
HAZARDS (FOISTIP)
``` Incorrect agent Simultaneous agent administration Free Standing Overfilling Tipping Intermittent Back Pressure “Pumping Effect” ```
47
Safety Mechanisms (VPICK)
``` Push/Turn Interlock Color Codes “Keyed” filler system Vigilance+Vigilance+Vigilance+… ```
48
Never fill the vaporizer with the
dial in the ON position
49
Be careful to keep the amount of liquid in the vaporizer
between the black lines.
50
Tipping the Vaporizer during Transport
Agent enters the bypass chamber Causes High Output Concentrations OVERDOSAGE Less of a problem with vaporizers that have extensive baffles (Tec 4)
51
If Tipping occurs:
- In hardened facilities turn in to maintenance - Flush for 20-30 minutes with high FGF and set the vaporizer concentration low - End-tidal agent monitoring
52
Intermittent Back PressurePumping Effect
1. Associated with positive pressure ventilation or oxygen flushing Oxygen flush is at __ psig-transmitted back Occurs during the inspiratory phase - PPV 2. Reverse flow through the vaporizing chamber back into the bypass chamber (Bypass has diluted vapor and vaporizing chamber is also saturated with vapor) 3. Causes higher than expected vapor concentrations
53
Intermittent Back PressurePumping Effect
1. Associated with positive pressure ventilation or oxygen flushing Oxygen flush is at _(50)_ psig-transmitted back Occurs during the inspiratory phase - PPV 2. Reverse flow through the vaporizing chamber back into the bypass chamber (Bypass has diluted vapor and vaporizing chamber is also saturated with vapor) 3. Causes higher than expected vapor concentrations
54
Pumping Effect is more Pronounced with
``` Low flow rates Low dial settings Low levels of agent in the chamber Rapid respiratory rates High peak inspired pressures Rapid drops in pressure during expiration ```
55
Vigilance Steps
- Make sure the vaporizer is in the OFF position after the machine check - Make sure that all filler ports are in place and secured tightly - Minimize possible leaks - Don’t overfill the vaporizer - Make sure the vaporizer has at least liquid up to the bottom line to minimize the pumping effect - Keep extra agent bottles in the drawer
56
Calculate % of oxygen or nitrous oxide given a total FGF
Ex: 1 L/min of O2 , 1 L/min of N2O | 1/1+1 = ½ = 50% O2 % 50% N2O
57
How to determine flow %
Flow of particular gas/Total gas flow
58
Commonalities – Modern Vaporizers | BALT- C
``` “Button” must be pressed Counterclockwise Agent specific T&P compensated Lock-out mechanism ```
59
Less soluble
WIll dissolve quicker
60
The temperature at Mount everest is about
220 mmHg so HIGHER gas will be delivered then set
61
Boiling point of each VA, and MAC of each And Coefficients
Volatile
62
Only Electronic vaporizer
TEC 6
63
Higher you go the LOWER
ATMOSPHERIC PRESSURE
64
TEC 6 has to reach
39 degrees C
65
WHy do we need so much DESFLURANE
because the solubility is so low INhale maybe 5.5, exhale could be 5.4 Meaning it's not BEING ABSORBED
66
The colder the patient
Their solubility is affected, slower metabolism | WIll take LONGER TO wake, NMB reversal more slowly
67
Higher atmospheric pressure _______output
LOWER
68
Lower atmospheric pressure _______output
HIGHER
69
Running sevo with less oxygen like (0.5L) can lead to
Compound A

SRNAProfessionalGuide II (13 decks)

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