Final Flashcards

1
Q

Vaporizers are included in this part of the gas distribution system?

A

Low pressure

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2
Q

List the vaporizer functions

A

–Change liquid anesthetic into vapor

–Deliver set dosage

–Deliver consistent concentration of agent vapor into anesthetic gas mixture

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3
Q

A __________ is an instrument designed to change a liquid anesthetic agent into its vapor and add a controlled amount of this vapor to the fresh gas flow

A

Vaporizer

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4
Q

What is the partial pressure of an agent in vapor phase?

A

Vapor pressure

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5
Q

The boiling point of a liquid is what?

A

The temperature at which vapor pressure equals atmospheric pressure

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6
Q

What is the amount of heat (calories) required to convert 1 g of liquid agent to a vapor?

A

Heat of vaporization

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7
Q

The speed at which heat flows through a substance is what?

A

Thermal conductivity

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8
Q

Vapor pressure is dependent on what 2 factors?

A

Temperature and liquid (substance)

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9
Q

True or False: Currently there are no ideal inhalational anesthetics

A

TRUE

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10
Q

For a blood/gas partition coefficient, the higher the number means ________

A

It is more potent because it wants to stay in the blood

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11
Q

For a oil/gas partition coeffecient, the _______ the number means more of the agent wants to stay in the tissue

A

higher

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12
Q

What is isoflurane’s VP, Blood/gas coefficient, and MAC values?

A

238 vp

  1. 36 blood/gas
  2. 15 MAC
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13
Q

What is sevoflurane VP, Blood/gas coefficient, and MAC values?

A

157 vp

  1. 6 blood/gas
  2. 05 MAC
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14
Q

What is desflurane VP, Blood/gas coefficient, and MAC values?

A

669 vp

0.45 blood/gas

6 MAC

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15
Q

Which anesthetic agent is the most potent?

A

Isoflurane

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16
Q

Which anesthetic agent is least potent?

A

Desflurane

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17
Q

T or F: More potent means the agent has slower onset and means slower it comes off

A

TRUE

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18
Q

What are the 2 effects of intermittent back pressure?

A

Pumping effect– increases vaporizer output

Pressuring effect– decreases vaporizer output

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19
Q

What is vaporizer formula?

A

Fa = Qv x Pa / (Pb - Pa) x Qt

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20
Q

What is percent of Isoflurane when fresh gas flow is 2L (Carrier gas flow is 100mL)

A

Pb= 760 Pa=240 Qt=2000 Qv= 100

Fa= 100 x 240 / (760-240) 2000

Fa= 0.023

2.3%

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21
Q

What device on vaporizer ensures that only one vaporizer can be used at a time.

A

vaporizer interlock

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22
Q

What are the 2 main purposes of the vaporizer manifold

A

–Provides places where vaporizers are mounted on the machine

–Provides passageway for fresh gas flow

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23
Q

The first vaporizer was?

A

Ether inhalation–rag soaked in ether and then placed over patients nose and mouth

Done by Dr. Crawford Long in 1842

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24
Q

T or F: Do you have to dilute a copper kettle?

A

TRUE

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25
T or F: All the gas passes through a copper kettle
FALSE
26
Are modern vaporizer's part of the breathing circuit (in circuit) or are they not part of the actual breathing circuit (out of circuit)
Out of circuit
27
Classification of modern vaporizers.
1. Variable bypass 2. Flow over 3. Temperature compensated 4. Agent specific 5. Out of circuit
28
Tec 5 vaporizers can hold approximately how much liquid anesthetic and how often do they need to be recallibrated?
~300 ml Every 3 years
29
How do Tec 6 vaporizers differ from the rest of the vaporizers?
Injection
30
What is main difference from Tec 5 to the Tec 7 vaporizers?
Filling configurations include agent specific funnels or Easy-fil adapters
31
Which anesthesia machine uses the aladin cassette vaporizers?
Aisys
32
What color is associated with isoflurane?
purple
33
What color is associated with sevoflurane?
Yellow
34
What color is associated with desflurane?
Blue
35
Why is it that the Tidal Volume you set is never what is actually delivered to the patient?
The circuit itself holds compliance
36
What are the circle system components?
CO2 Absorbent, Reservoir Bag, Bag/Vent Switch, Ventilator, Pressure Gauge, Gas monitor sensor airway pressure monitor, CO2 Absorbers, respirometer, Unidirectional Valve Inspiratory / Expiratory Ports, Breathing Tubes Y-piece, Fresh Gas inlet, APL Valve
37
What is the function of the CO2 absorbent and what are the main types?
Neutralize carbonic acid Soda lime (primary) and barium hydroxide lime
38
What are 3 CO2 absorbent properties?
Granule size (smaller granules have high absorptive surface area) Hard (prevents dust formation) Moistness (Dry granules will absorb and degrade volatile anesthetics more)
39
When do you need to change the CO2 absorbent?
When you see FiCO2 in the inspired gas Color change from white to purple Heat in the cannisters (reaction with CO2 produces heat)
40
T or F: Tube length doesn’t affect dead space because of unidirectional gas flow
TRUE
41
On the Y-piece what size connectors lead to the breathing tubes?
22 mm
42
On the Y-piece, what size connector leads to the ETT tube?
Female 15 mm
43
Name 2 functions of the APL valve
Controls pressure in breathing system Releases gases to scavenging system
44
Explain fresh gas flow when using low flows
Require CO2 absorber Vary O2 & anesthetic concentrations Prolong induction & recovery
45
Explain fresh gas flow when using high flows
\> 5 L/min don’t require CO2 absorber Accelerate induction & recovery Compensate for circuit leaks Decrease unanticipated gas mixture risk
46
Resistance is increased in the circuit by what?
Unidirectional valves CO2 absorber Coaxial tubings
47
No matter how long the circuit is, the dead space remains the same as long as you have __________ flow
unidirectional
48
T or F: When flow becomes bidirectional, then dead space will increase
TRUE
49
What gases is in the reservoir bag?
Expired gas including CO2 because hasn’t been scrubbed yet by CO2 absorber
50
When does CO2 get absorbed?
Just before inhalation, just prior to mixture with fresh gas flow
51
Define scavenging
Collection of excess gases from equipment used to administer anesthesia or exhaled by the patient & the removal of these gases to an appropriate place of discharge outside the work environment
52
What are the parts of the scavenging system?
* Gas-collecting assembly (collects excess gases) * Transfer tubing (carries collected gas to interface) * Interface (Provides positive and negative pressure relief) * Gas-disposal tubing (carries gas from interface to disposal system) * Gas-disposal system (discharges gases)
53
The gas collecting assembly uses what size outlet connection?
30 mm
54
Transfer tubing uses what size connection fittings?
19 mm inlet 30 mm outlet
55
What is the main function of the interface?
Prevents pressure increases/decreases in scavenging system from being transmitted to breathing system or ventilator
56
Features of an open interface
Has 1 or more openings to the atmosphere Contains no valves Used only with active disposal Reservoir needed to hold gas surges
57
What is the design of an open interface scavenging system?
* Parallel tubes inside canister (1 carries waste gases to bottom of canister, 1 carries gases from bottom to disposal system) * Open ports at top of canister provide positive and negative pressure relief * Flow control valve regulates scavenging flow
58
What are the features of the closed interface system?
Connects to atmosphere through valves Positive pressure valve required Negative pressure valve required only if active scavenging Reservoir not required
59
T or F: Passive disposal systems have piping directly to the atmosphere
TRUE
60
What is the gas that cannot be absorbed by passive disposal systems?
N2O (nitrous oxide)
61
An open interface should only be used with what type of gas disposal?
Active
62
What is always required with a closed interface?
Positive pressure relief valve
63
What gas can not be absorbed?
Nitrous
64
What is always required with an active duct system?
Negative pressure relief valve Positive pressure relief valve
65
What colors are associated with scavenging?
Purple and yellow
66
Which CO2 cannister will you change out first, the top or the bottom?
TOP
67
Why do you change out top cannister first?
Because flow starts are top and distributes down
68
What is the fresh gas inlet?
Where fresh gases with/without anesthetics enter the breathing circuit
69
Name some functions of the reservoir bag?
Allows gas to accumulate during exhalation Provides method for generating positive-pressure vent Provides way to monitor spontaneous respiration Protects pt from excessive pressure in breathing system
70
What is the gas called that pushes the bellows down during \_\_\_\_\_\_\_\_\_\_?
Drive gas Inspiration
71
What is the primary gas that pushes the bellows up during \_\_\_\_\_\_\_\_\_\_?
Patients expiratory breath Expiration
72
What does the repirometer measure?
Ventilatory volumes
73
What are the circle system design objectives?
Maximize inclusion of fresh gas Maximize venting of alveolar gases Minimize absorbent dessication Minimize absorbent consumption Provide accurate repirometer readings
74
List the order of the circuit system from patient expiration to when the gas gets the inspiratory limb (spontaneous breathing)
Pt lungs, Y-piece, Expiratory limb, expiratroy check valve, reservoir bag until full, excess flows out APL valve AT START OF INSPIRATION Reservoir bag, CO2 canister, fresh gas inlet, inhalation check valve, inspiratory limb, Y piece, Pt lung
75
List the order of the circuit system from fresh gas inlet to fresh gas inlet when on mechanical ventilation
Fresh gas inlet, inhalation check valve, Inspiratory limb, Y-piece, pt During expiration Y-piece, expiratory limb, exhalation check valve, Ventilator (bellows), CO2 canister, Fresh gas inlet
76
What is the difference in the drager circle system and datex circle system?
Drager has piston ventilation, so patients expiration does not push bellows up during mechanical ventilation. FRESH GAS FLOW FILLS THE PISTON IN DRAGER
77
Name the advantages of the circle system
Economy Reduced OR pollution / reduced environmental pollution Good estimation of anesthetic agent uptake / O2 consumption Heat and humidity conservation Reduced barotrauma risk
78
What are the disadvantages to the circle system?
Larger overall circuit size / increased complexity Less portable Increased resistance Canot predict inspired gas concentrations with low FGF Faster absorbent exhaustion Hypercarcbia risk
79
What are the main locations for gas collecting assemblies?
Breathing systems Ventilators Respirtory gas monitor Leak sites
80
What organization is responsible for the standards associated with scavenging?
ASTM American society of testing and materials
81
Open interface can only be used with what type of disposal?
Active disposal
82
All of the following are true about closed interface except: A) Positive pressure relief valve always required B) Negative pressure required only with active disposal C) Reservoir not required D) All are true
D) all are true
83
With a passive disposal system, what type of interface should be used?
A closed interface with only positive pressure relief
84
T or F : With passive disposal system, the negative pressure relief valve is always closed
TRUE
85
What are the advantages of passive disposal ?
Simpler Less expensive
86
What are some disadvantages to passive disposal?
Not as effective in lower trace gas levels because positive pressure promotes outward leaks
87
What are some advantages to active disposal?
More effective at keeping pollution levels low Allows small bore tubing No excessive resistance Aid in room air exchange
88
What are some disadvantages to active disposal?
Expensive Not automatic More complex Requires interface to have negative pressure relief
89
What is the size of the waste gas reservoir bag?
3 L