I. Anesthesia Workstation Flashcards
(96 cards)
1
Q
Who created the first Anesthesia delivery system?
A
Dr. Crawford long (1842)
LONG time ago
2
Q
What was Dr. Crawford Long’s mechanism of anesthetic delivery?
A
Ether soaked towel
3
Q
Who created the second anesthesia delivery system and when?
A
William Morton, 1846
Morton Etherizer
4
Q
What is Joseph clover responsible for?
A
Joseph Chloroform Clover
Clover’s Chloroform Apparatus (1862)
Clover’s Portable regulating ether inhaler (1877)
5
Q
Who is responsible for creating the Nargraf Machine which allowed for fine adjustments of anesthetic, gases, measurement, recording, and suctioning?
A
Elmer McKesson (1930)
Elmer Fud shot a Narwall
6
Q
Who developed the Connel apparatus?
A
Dr. Karl Connel, 1936
7
Q
What were the first two Anesthesia machines?
A
Drager Romulus (1952)
Datex-Ohmeda Excel (1987)
8
Q
What are the two major anesthesia machine suppliers?
A
North American Drager
GE Datex-Ohmeda
9
Q
Which supplier has the following models: Aisha, Aespire, Avance?
A
Drager
10
Q
Which Anesthesia supplier has the following models: Apollo, Perseus, Fabius GS?
A
GE Datex-Ohmeda
11
Q
What are the five basic functions of an anesthesia machine?
A
- Control the patient’s inspired gas composition.
- Control and monitor the patient’s minute ventilation and ventilatory pattern.
- Monitor physiological functions and breathing circuit gas composition.
- Prevent OR contamination with anesthetic waste gases
- Provide safety controls.
12
Q
What are the two main types of systems?
A
- Electrical system.
- Pneumatic system.
13
Q
What are common features of the electrical system?
A
- Master switch.
- Power failure indicator.
- Back up battery power.
- Electrical outlets
- Circuit breakers.
14
Q
What are the three stages of pneumatic systems?
A
- High-pressure.
- Intermediate pressure.
- Low pressure.
15
Q
What are the two types of gas supply?
A
- Pipeline.
- Cylinder.
16
Q
What is the primary gas source?
A
Pipeline supply
17
Q
What are the common gases found within a pipeline supply?
A
- Oxygen.
- Nitrous.
- Air.
- Carbon Dioxide
- Helium
- Xenon
(Vacuum lines also)
18
Q
What is the normal working pressure?
A
45-50 psi
19
Q
What safety system do pipeline attachments use?
A
DISS
20
Q
What is the color code for oxygen?
A
Green
21
Q
What is the color code for air?
A
Yellow
22
Q
What is the color code for nitrous oxide?
A
Blue
23
Q
What is the color code for vacuum?
A
White
24
Q
What psi is measured at the wall outlet for oxygen?
A
50 psi
25
What two gases are used to operate pneumatic surgical tools?
1. Compressed air (200 psi)
2. Nitrogen (200 psi)
26
What gas is used for insufflation?
Carbon dioxide
27
What are two other functions of the pipeline they do not directly involve the addition of gases?
1. Vacuum (negative pressure for suction)
2. AGSS (Anesthesia gas scavenging system)
28
What does the anesthesia gas scavenging system do?
It captures and dispose is volatile gases
29
How is oxygen stored for use by the hospital?
Oxygen stored as a bulk liquid in a remote location away from the hospital
30
 Where does the air supply come from for the hospital?
It is usually created by special hospital compressors with a quarterly air quality monitoring
31
How is nitrous oxide stored for used by the hospital?
Nitrous is stored in banks of G or H cylinders with automatic switching
(Nitrogen, and carbon dioxide [95/5] is stored the same way)
32
Where are pipeline alarm systems normally found
Near engineering, respiratory therapy, or in local areas, such as OR, PACU, ICU
Alarms are not available in every room
33
Where are medical gas shut off valves found
Inside the gas shut off zone box
34
What is the gas control panel used for?
For operation of surgical appliances
35
What are components found on the Anesthesia utility columns?
1. Oxygen.
2. Vacuum.
3. Nitrous oxide.
4. Air.
5. Scavenging.
6. Electrical power signals.
36
What is the gas supply for the high-pressure system?
Cylinders
37
What range of pressures are found within the high-pressure system?
2200 - 45 psi
38
What components are found within the high-pressure system?
1. First stage regulator.
2. Check valves.
3. Gas supply modules.
4. Hanger yoke assembly.
5. Pressure gauges
6. Cylinders
39
What is the first stage pressure regulator responsible for?
Reducing high pressures found within the cylinders to working pressure of 45 psi
40
What type of cylinders are reserve cylinders?
E-cylinders
41
What is the primary function of the E cylinder?
To provide a alternate gas source for pipeline failures
42
Should the E-cylinder remain open or closed when not in use?
Closed
43
What safety system does cylinders utilize?
PISS
44
What is the maximum pressure found within oxygen cylinder?
2000 PSI
45
What is the maximum pressure found within an air cylinder?
1800 psi
46
What is the maximum pressure found within a nitrous oxide cylinder?
745 psi
47
What component of the high-pressure system reduces high pressures found within the cylinders to a lower, working pressure of 45 psi?
First stage pressure regulator
48
What are the three landmarks on the pin index safety system?
1. Valve stem.
2. Valve outlet.
3. Index holes.
49
what are the three functions of the hanger yolk assembly?
1. Orient the cylinder.
2. Provides Unidirectional flow.
3. **Ensures gas tight seal via check valve.**
Hint: SOF eat their egg YOLKS
50
What are two functions of the check valve found within the hanger yolk assembly?
1. The check valve prevents gas from exiting the machine when a cylinder is being replaced. (Unidirectional flow)
2. It also prevents trans-filling (transfer of gas from one cylinder to another.)
51
What is an important caveat concerning the check valve?
It is not a permanent seal, in other words it may leak when a yolk is left vacant
52
What are the two measurement gauges found on each of the gas supply clusters?
1. Pipeline supply.
2. Cylinder supply.
53
What color code corresponds with the carbon dioxide cylinder?
Gray
54
What is oxygens physical state within a cylinder?
Gas
55
What is nitrous oxides physical state within the cylinder?
Liquid and gas
56
What is carbon dioxide physical state within the cylinder?
Liquid and gas
57
What is air’s physical state within the cylinder?
Gas
58
how many liters of oxygen are held within a full cylinder?
625
59
How many liters of nitrous oxide can be held within a full cylinder
1590
60
How many liters of carbon dioxide can be held within a full tank
1590
61
How many liters of air can be held with a full tank?
625
62
What is the weight of an empty E cylinder?
5.9 kg
63
What is the weight of a full cylinder filled with nitrous oxide?
8.8 kg.
64
What is the weight of a full cylinder filled with carbon dioxide?
8.9 kg.
65
What is the weight of a full cylinder filled with oxygen?
6.76 kg.
66
What is the maximum pressure of a full carbon dioxide cylinder?
838
67
What is the conversion factor for determining the remaining volume of OXYGEN or AIR remaining in the cylinder and how is it derived?
(Total Liters/Total PSI)
OXYGEN & AIR: 625L/2000 psi = ~0.3
N20: 1590L/750 = ~2.1
68
How do you calculate the time remaining before E cylinder of oxygen runs out?
1. (Pressure Remaining) x (Conversion Factor) = Remaining Volume (liters)
Ex: (1000 psi) x (0.3) = 300 L
2. (Liters Remaining)/(flow rate [L/min]) = Minutes Remaining
Ex: (300 L)/(0.5 L/min) = 600 min
69
At room temperature, in what physical state is nitrous oxide?
Both a liquid and gas
70
What is interesting about the pressure of a nitrous oxide cylinder as it is being used?
- The pressure remains 750 psi, even as the volume is being reduced
- however once the volume reaches 25% capacity, the pressure begins to fall below 750 psi
- Therefore in order to get an accurate measurement of remaining volume it is necessary to weigh the nitrous oxide Tank.
71
How many liters does 25% cylinder capacity of nitrous oxide correspond to?
400 L
72
What is unique about the nitrous oxide tank calculation regarding the ideal gas law?
The ideal gas law can only be applied to nitrous oxide in gaseous form (remember: nitrous oxide is present in both gas and liquid form in the tank) once the cylinder pressure drops below 750 psi.
73
Visual representation of nitrous oxide cylinder as it is depleted:
74
What is the other name for the first stage regulator?
Pressure reducing valve
75
What pressures are found within the intermediate pressure system
45 - 50 PSI
76
What is the gas supply for the intermediate pressure system?
1. Direct pipeline inlet.
2. REGULATED cylinder.
77
What components are found within the intermediate pressure system?
1. Pressure gauges.
2. Failsafe valve.
3. Oxygen supply, low pressure alarm
4. **Second stage pressure regulator**
5. **Oxygen flush valve**
78
What is the oxygen failure protection device (OFPD)?
- this is a **pressure sensor shut off valve**
- This failsafe valve triggers, a certain action in case of a failure in order to **prevent administration of hypoxic mixture** to patient
- Ensures oxygen flow through common gas outlet even as supply pressures fall
- **loss of oxygen pressure will result in a high priority alarm, both audio and visual**
79
To what levels of psi do the **second stage regulators** reduce *oxygen* and *nitrous oxide*?
O2: 12 -19 PSI
N2O: 26 PSI
80
What is the other key function of the second stage regulator?
It minimizes pressure fluctuations within machine
81
What does the oxygen flush valve do?
1. Provides direct communication between intermediate and low pressure systems.
2. Delivers 35 to 75 L per minute oxygen to the patient circuit. 
82
When should you never use the oxygen flush valve?
Do not use during inspiratory phase of positive pressure ventilation. This risk high pressure barotrauma.
83
What is the other consideration when using the oxygen flush valve?
The oxygen flush valve bypasses vaporizers and dilutes anesthetic agent concentration
84
What pressures are found within the low pressure system?
Ambient room pressure
85
What are the components of a low pressure system?
1. Flow meters.
2. Vaporizers.
3. Pressure relief valve.
4. Outlet check valve.
5. Common gas outlet.
86
Illustration of flow meter diagram
87
What is the other name for the flow meter?
Thorpe Tube
88
When gas enters the flow meter what does it elevate?
Either the “bobbin” or “float”
89
What are the three factors that affect the rate of gas flow through the flow meter tube?
1. Resistance to gas flow.
2. Physical properties (density, and viscosity) of gas
3. Pressure dropped along the length of tube.
90
How to read the flow meter diagram:
Ball: read center
Float: read top
91
What are the four flow meter safety features?
1. One knob for each gas.
2. Oxygen on right (nearest route of egress)
3. Oxygen downstream.
4. Color-coded.
92
Illustration describing flow meter placement:
93
What are the four flowmeter knob, safety features?
1. Oxygen knob is larger.
2. Oxygen knob protrudes.
3. Oxygen knob is fluted.
4. Color-coded.
94
What is the link 25?
- The link 25 is a hypoxic guard system
- it is a proportioning system that prevents delivery of a hypoxic mixture.
- Depending on the model, nitrous and oxygen are interfaced mechanically or pneumatically
- The **minimum** allowable **oxygen concentration** delivered at the common gas outlet is **23 to 25%**
- **minimum ratio of oxygen to nitrous is 3:1**
*(The older Datex Ohmeda mechanical version is called the link 25 is it maintains a minimum of 25% oxygen)*
95
What are five reasons a hypoxic mixture can occur?
1. **Oxygen delivery is less** than consumption by the patient.
2. **Wrong supply gas** in oxygen pipeline or cylinder.
3. **Defective** pneumatic, mechanical, or electronic **components**
4. **Leaks exist** downstream of flow control valves.
5. If third **inert gas** (such as helium) is used (not true of electronic gas mixtures)
96
What are six different uses of oxygen in the anesthesia machine?
1. Drives the ventilator (bellows)
2. contributes to fresh gas flow (FGF)
3. Provides gas for oxygen flush
4. Trigger for low, oxygen alarm.
5. Trigger for the failsafe valves.
6. Plays roll in hypoxic guard system.
