Anesthesia Machine Flashcards
(135 cards)
1
Q
Where is the high pressure system? What is included?
A
Begins at cylinder and ends at the first pressure regulator
Hanger yoke and yoke block
Cylinder pressure gauge and regulator
2
Q
Where is the intermediate pressure system?
What is included?
A
Begins at pipeline and ends at the flow meters
-Pipeline inlets
-Pressure gauges
-O2 pressure failure device
-O2 second stage regulator
-O2 flush valve
-Vent power inlet
-Flowmeter valve
3
Q
What is the pipeline pressure?
What is the tank pressure after the first pressure regulator?
A
Pipeline = 50 psi
Tank = 45 psi
4
Q
Where is the low pressure system? What is included?
A
Begins at flowmeter tubes and ends at the common gas outlet
-Flowmeter tubes
-Vaporizers
-Check valve
-Common gas outlet
5
Q
What is the low pressure leak test (negative pressure test)?
When should this be done
A
-Checks the low pressure system
-Creates pressure at Negative 65 and if the bulb reinflates within 10 seconds, it fails
6
Q
What is the high pressure leak test?
A
Close the apl valve to 30 and watching the gauge - should remain constant
-Evaluates the low pressure system
7
Q
What signifies a failed low-pressure leak test?
A
If the bulb reinflates within 10 seconds after creating -65 of pressure
8
Q
How much negative pressure should be created for a proper negative pressure test?
A
-65 cm H2O
9
Q
Should the vaporizer be on or off during a low pressure leak test?
A
Off at first but then repeated with them on
10
Q
What are the 5 tasks of oxygen in the anesthesia machine?
A
- O2 pressure failure alarm
-O2 pressure failure device
-O2 flowmeter
-O2 flush valve
-Ventilator drive gas
11
Q
What are the 4 components of the SPDD model?
A
Supply
Processing
Delivery
Disposal
12
Q
The PISS system is used to:
A
prevent the hookup of the wrong cylinder
13
Q
The DISS system is used to:
A
Prevent the wrong hose from being hooked up
14
Q
What does the pressure change to when going from the high pressure system to the low?
A
1900 to 45 PSI
15
Q
What is the PISS configuration of O2?
A
2,5 - green
16
Q
What is the PISS configuration of Air?
A
1,5 - Yellow
17
Q
What is the PISS configuration of NO2?
A
3,5 - Blue
18
Q
Good way to remember the PISS?
A
The second number is always 5
O2 - 2
Air - 1
N20 - 3 (3)
19
Q
What is the best way to identify what gas is in the tank?
A
The LABEL
NOT color
20
Q
How many Liters are in a full tank of O2? What is the PSI?
A
660 L
1,900 PSI
Pin 2,5
21
Q
How many Liters are in a full tank of Air? What is the PSI?
A
625 L
1900 PSI
Pin 1,5
22
Q
How many Liters are in a full tank of N20? What is the PSI?
A
1590 L
745 PSI
Pin 3,5
23
Q
How is N2O stored? What is the only reliable way to measure how much is left?
A
Liquid form till it’s almost empty
Weigh it
24
Q
When should the N2O tank be changed?
A
When the PSI drops
25
How should a cylinder be stored? Changed?
-Always store upright
-Okay to lay down when changing
-Never apply lubrication
-Take plastic cover off before installing
-Place yoke plug if no tank in use
-Never take into an MRI room
-Okay to use one yoke washer but never two
26
What helps prevent a cylinder explosion?
-Never store at temps higher than 130F or 57 C
-Use a fusible plug made from Woods metal; Bismuth, lead, tin, cadmium (BLT w/ Cheese)
-A valve that opens at high temps
-A disk that ruptures under pressure
-Always open slowly
27
How often must a cylinder be tested?
Every 5 years
10 years with a special permit
28
Who sets the standards for the required components of the anesthesia machine?
American Society for testing
29
Who sets the standards for the required anesthesia machine checkout?
FDA
30
Who sets the standards for the required compressed has cylinders?
DOT
31
Who sets the standards for the required volatile gas exposure?
OSHA
32
When is the oxygen pressure failure activated? Where is it located?
O2 supply falls below 20 PSI
Does NOT monitor for a crossover or a flowmeter leak
Intermediate system
33
The hypoxia prevention safety device on the anesthesia machine will limit what?
A hypoxic mixture. Does not allow N2O to be more than 3x the flow of O2
34
What are 4 situations where the proportioning device can not prevent a hypoxic mixture?
A flowmeter leak
A crossover
Defective pneumatics
A third gas
35
What is the minimum FiO2 of the proportioning device?
25%
36
What is Reynolds number?
The flow rate through the tube that determines if something is laminar or turbulent
<2000 - laminar
2000-4000 Transitional
>4000 turbulent
37
Where should the o2 flowmeter be located?
The last one. Furthest to the right
Prevents hypoxic mixture
Because flowmeters are made of glass. If it breaks the glass will leak out.
38
What is the equation for Reynolds number?
Density
*Diameter
*Velocity
Divided by
Viscosity
39
How to calculate FiO2?
FiO2 = (air flow rate * 21) + (O2 flow * 100)
Divided by
Total flow rate
40
What should you do if a vaporizer tips over?
Drain the vaporizer to remove all liquid
Turn the dial to the highest setting and run high FGF for 20-30 minutes
41
What is the T setting on the vaporizer?
Transport mode- Don't need to worry about the vaporizer tipping over
42
What is the most common cause of a vaporizer leak?
Loose filler cap
43
Does a variable bypass vaporizer need to be calibrated for elevation?
No
44
How does the vaporizer minimize the effect of cooling on vapor pressure and vaporizer output?
The temperature compensating valve adjusts the ratio of flow
45
Isoflurane dial is set to 2%. What percent of fresh gas exiting the VAPORIZING CHAMBER is saturated with iso?
(This is a variable bypass)
100%
Some fresh gas enters and saturates with 100%
The remainder of fresh gas bypasses and mixes after the vaporizer
Flow over method
46
How does a TEC 6 vaporizer work? (This is Injector)
Des has a vapor pressure closer to atmospheric pressure
Tec 6 injects a precise amount of vaporized Des directly into the fresh gas flow
Output is increased inside a hyperbaric chamber
Pressurized to two atmospheres
Heated to 39 degrees
Does not split gas
Heat creates vapor
47
Which vaporizers compensate for elevation?
Variable bypass
*Tec 6 needs to be recalibrated
48
Which vaporizer requires electrical power?
Injector (Tec 6)
49
Which vaporizer has a dual circuit design?
Injector (Tec 6)
50
Which device is the first to detect an oxygen pipeline crossover? Where is it located?
O2 analyzer - Inspiratory limb
51
What are the two types of O2 analyzers?
Galvanic fuel cell - must be calibrated daily and replaced
Paramagnetic device - self calibrating, FASTER response time
52
** What is the normal O2 consumption of the average adult?
250mL/min
53
Why will a pyrexic 70kg patient become hypoxic with an O2 flow rate at 250mL/min in a closed circuit system?
Pyrexic patients require more O2 then the standard 250mL.
54
What other conditions increase O2 consumption?
Fever, Sepsis, thyrotoxicosis
55
What are the most critical actions to perform during an O2 pipeline crossover?
-Disconnect the pipeline supply
-Turn on O2 tank
56
What should be at the top of your differentials when the O2 analyzer alarms?
O2 pipeline crossover
57
What minimizes the risk of barotrauma when using the O2 flush valve?
Ventilators with fresh gas decoupling
58
When the O2 flush valve is pressed, What is the flow of O2? What is the pressure?
35-70L
50 Psi from the pipeline
59
Using the O2 flush valve can cause what?
Barotrauma
Awareness from dilution of anesthetic gas
60
What are the two functions of the drive as on a pneumatic ventilator?
1. Compress the bellows
2. Opens and closes the ventilator spill valve
61
Methods to reduce barotrauma?
Fresh gas decoupling (isolate the tidal volume from the flowmeters and O2 flush valve)
Inspiratory pressure limiter (APL valve)
62
What is an off label use for the O2 flush valve?
As a jet ventilator (Not recommended by manufacturer
63
What position is the ventilatory spill valve in during inspiration?
Closed - to ensure delivery of set TV
64
What is the minimum expiratory pressure needed to open the ventilator spill valve?
3 cm h2o
65
If there is a hole or leak in the bellows of a pneumatic ventilator what may happen?
- An INCREASE in the O2 analyzer
- Barotrauma
*bellows can still drive
66
What changes with Descending or upside down bellows
-Falls with expiration
-May continue to rise and fall with circuit disconnect
-May cause low volume and low pressure alarms
67
What is different with a piston driven ventilator?
-Preserves tank oxygen because it is not relying on the gas for the driving pressure
-Allows for a more precise delivery of tidal volumes
68
Which ventilator delivers 3cm h2o of intrinsic peep?
-Bellow driven
69
Which ventilator decouples FGF from Vt
Piston driven
70
Which ventilator contains a negative pressure relief valve?
Piston driven
71
Which ventilator contains a positive pressure relief valve?
Piston driven
72
Does the reservoir bag inflate with expiration on a piston ventilator? On inspiration?
No
Inflates with inspiration
73
Is lung injury increased or decreased with a pressure controlled ventilation?
Decreased
74
Does gas flow accelerate or decelerate during inspiration with PCV?
Decrease
75
What is a disadvantage of PCV?
Increased in airway resistance or decreased lung compliance reduces tidal volume
Requires extra attention with conditions that alter pulmonary resistance or compliance
76
PCV - What conditions decrease compliance?
Pneumoperitoneum
Trendelenburg position
77
PCV - What conditions decrease resistance?
Bronchodilators
Removing airway secretions
78
PCV - What conditions increase compliance?
Release of pneumoperitoneum
Going from Trendelenburg to supine
79
PCV - What conditions increased resistance?
Bronchospasm
Kinked ETT
80
What increases Vt?
increased compliance
decreased resistance
81
What decreases Vt?
Decreased compliance
Increased resistance
82
When is PCV better than VCV?
-Patient has low compliance
-High Pip would be dangerous
-Compensate for a leak
83
What patients are at risk for low compliance?
Pregnancy
Obesity
Laparoscopy
ARDS
84
What patients would high PiP be dangerous?
LMA
Neonate
Emphysema
85
What patients need to compensate for an air leak?
LMA
Uncuffed ETT in children
86
What ventilator mode has a fixed inspiratory flow?
VCV
87
What ventilator mode has a fixed tidal volume?
VCV
88
What ventilator mode has a fixed PiP?
PCV
89
What ventilator mode has a variable Inspiratory flow?
PCV
90
What ventilator mode has variable tidal volume?
PCV
91
What ventilator mode has a variable PIP?
VCV
92
What ventilator mode is best for an LMA
SIMV
Pressure Support
93
When is Inverse Ratio ventilation (IRV) used?
Small FRC and ARDS
*****MUST be paralyzed and sedated
Risk of hyperinflation or auto peep
94
When using assist control, is respiratory acidosis or alkalosis a risk?
Respiratory alkalosis
95
Does pressure support have a backup for apnea?
No
96
Does BiPap require a set Vt?
No
97
At what pH does the ethyl Violet turn purple?
10.3
98
How does soda lime react?
-CO2 and water create carbonic acid
-Carbonic acid creates sodium carbonate
-Sodium carbonate creates calcium carbonate and sodium hydroxide
99
What is the best balance of mesh granules?
4 - 8 Mesh
Granules around 1/4 diameter
100
What are the two main problems with soda lime?
-Exhausted - unable to neutralize CO2
-Desiccated - too dry
101
What role does silica play in CO2?
Provides hardness and minimizes dust production and decreases flow resistance
102
Does turning purple indicate desiccation ?
No. Only if it is exhausted
103
What are the benefits of Calcium hydroxide lime?
- No Carbon monoxide production
-Minimal Compound A production
-Lower risk of fire
104
What are the drawbacks of Calcium hydroxide lime?
Lower CO2 absorption
Frequent cannister changes
More expensive
105
A patient is ventilating spontaneously with an ET tube, a FGF of 10L is required to fill the breathing bag and you determine it is a malfunctioning scavenger system. Why?
An active system is using too much suction because the negative pressure relief valve has failed
106
What is the function of the scavenging system? What is the most critical component?
Remove excess gas from the anesthesia circuit
Interface
107
What happens if they scavenger removes too much gas? Too little?
Too much - negative pressure in circuit
Too little - barotrauma
108
What controls the scavenger during spontaneous ventilation?
APL valve
109
What controls the scavenger during mechanical ventilation?
Ventilator spill valve
110
What are the five components of the scavenging system?
1. Gas collecting assembly
2. Transfer tubing
3. Interface
4. Gas disposal tubing
5. Gas disposal system
111
What determines if the scavenger system is open or closed?
-The interface
112
What type of scavenging system communicates with the atmosphere with pressure valves
Closed
113
What valves must be present on closed interface - active system?
1. Negative and Positive pressure relief valves
114
What is the most common cause of low circuit pressure?
Circuit disconnect
1. Y piece
2. Co2 cannister
115
What is the most common source of preventable equipment related complications?
Circuit disconnect
116
4 ways to evaluate circuit disconnect
-Pressure
-Volume
-EtCO2
-Your vigilance
117
You notice a high-pressure alarm but it goes away when the ventilator is switched over to bag. What is the cause?
Ventilator spill valve malfunctioned
118
What are 4 CV consequences caused by excessive pressure in the breathing circuit?
-Decreased Venous return
-Decreased cardiac output
-Hypotension
-Cardiovascular collapse
119
If the ventilator spill valve fails during a case, what do you do?
Bag
TIVA
120
What are the OSHA recommendations for gas exposure?
Solo Nitrous < 25 ppm
Solo agents < 2 ppm
Combined agents < 0.5 ppm and <25 ppm
121
What would cause a negative pressure inside the breathing circuit?
-Malfunctioned of a closed system scavenger
-OG in the trachea
122
What is the most likely cause of a lower-than-expected concentration of sevo in the breathing circuit?
A bellow leak
123
What would cause a higher concentration of sevo in the breathing circuit?
-Tipped vaporizer
-Pumping effect
-NOT altitude because sevo automatically adjusts
124
What is the minimum pressure when performing a high pressure leak test?
30
125
When will you see a negative deflection in the airway pressure waveform ? What about a positive?
-Negative - The patient is initiating the breath
-Positive - Machine initiated
126
What two devices will notify you of a pipeline crossover?
-O2 Analyzer
-SpO2 (Very very late sign)
127
What is laminar flow dependent on? What law?
Gas viscosity - Poiseuille
128
What is turbulent flow dependent on? What law?
Gas density - Graham
129
How do you determine the tidal volume on a ventilator that uses fresh gas coupling?
Vt = Vt on ventilator + FGF
130
When using a ventilator that couples fresh gas flow to tidal volume, what types of changes will impact the Vt delivered to the patient?
Increase Vt
-Decrease RR
-Increase I:E
-Increase FGF
-Increase bellow height
Decrease Vt
-Increase RR
-Decrease I:E
-Decrease FGF
-Decrease Bellow height
131
If the soda lime is exhausted in the middle of gas what is the best action to take?
1. Replace cannister
2. Increase FGF to convert to a semi-open system from a circle system
132
What is produced from Sevo? What does this lead to?
Compound A
Renal Dysfunction
133
What is produced from Iso and Des? What does this lead to?
Carbon monoxide - carboxyhemoglobinemia
Des > Iso
134
What role does water play in CO2 absorbent?
Required to facilitate the reaction of CO2
Granules are 15% water weight
135
What safety mechanism does not monitor for a disconnection of the breathing circuit?
O2 analyzer - Just monitors the concentration
