Exam 3 Anesthesia Machines (Workstations) (7/8/24) Flashcards
What 5 things should an anesthesia machine provide?
- Accurate and safe gas delivery
- A means for ventilating patients (Primary method)
- Electrical Outlets
- A housing for monitoring devices
- Storage/Shelving
If the Master power switch has been turned off, electrical functions will be disabled except for:
- Battery Charger
- Electrical Outlets
- Oxygen flush valve
- Auxillary oxygen flowmeter
True or False:
Other appliances (not intended for anesthesia monitoring) should be plugged in to the anesthesia machine outlets in order to save wall space.
FALSE:
Other appliances should be plugged into hospital main
If requirements exceed outlet, this happens:
Circuit breaker will activate and entire machine will fail.
What are the 3 parts to the pneumatic system?
- High Pressure
- Intermediate Pressure
- Low Pressure
The machine receives gases from the cylinders at high, variable pressures of about ___ psi and reduces them down to ___ psi.
2200 psi
45 psi
What is utilized by the anesthesia machine to reduce/provide a more constant pressure once gases are received from the cylinders?
A Pressure (1st Stage) Regulator
What is this an image of?
A Hanger Yoke
What are the functions of the Hanger Yoke?
- Orients and supports the cylinder
- Provides a gas-tight seal
- Ensures a unidirectional flow (safety valves inside)
We are required to have at least 1 Hanger yoke for which of the following?
Oxygen
Medical Air
Nitrous
Oxygen and Nitrous
For each of the following, label the name of what each part of the hanger yoke is responsible for:
Tightening the cylinder
Area where gas enters the machine
Prevents attachment of an incorrect cylinder
Forms seal between the cylinder and yoke
Ensures unidirectional flow
Tightening the cylinder: Retaining Screw
Area where gas enters the machine: Nipple
Prevents attachment of an incorrect cylinder: Index Pins
Forms seal between the cylinder and yoke: Washer
Ensures unidirectional flow: Check valve assembly
What does the check valve assembly prevent?
Prevents gas from exiting machine when there is no cylinder in the yoke
Prevents gas from being transferred from a cylinder with higher pressure to one with lower pressure
What are the names of the tubes found in the cylinder pressure indicator?
Describe the look of these tubes.
Bourdon Tubes
Curved and Hollow
The cylinder pressure indicator/gauge is required to be calibrated in which of the following two units?
A. Newtons
B. PSI
C. Pascals
D. Joules
E. Kilopascals (kPa)
B. PSI
E. Kilopascals (kPa)
How is gas introduced into the Intermediate portion of the pressure system?
Receives gases from the pressure regulator or pipeline
(45 psi 1st stage regulator) (50-55 psi pipeline)
The intermediate pressure system includes these 6 things:
- Pneumatic part of master switch
- Pipeline inlet connections and indicators
- Piping
- Oxygen pressure failure devices
- Oxygen flush valve
- Flow control valves
How are the pipeline inlet connections fitted?
Via the DISS (Diameter Index Safety System)
Are the top or bottom pressure indicators reading the pressures from the wall or from the cylinders?
Top: Wall
Bottom: Cylinder
In the intermediate pressure system, the piping must be able to withstand ___ the intended pressure.
It must also not allow leaks to exceed ___ inside the machine.
4x intended pressure
25 ml/min inside the machine
When will the oxygen failure safety device alarm?
If oxygen pressure is reduced to 30 psi
How long will it take for an alarm to sound if there is complete oxygen failure?
5 seconds
This device receives oxygen from pipeline inlet or cylinder pressure regulator and sends O2 to common gas outlet
Oxygen flush
The oxygen flush must have a flow between ___ and ___.
35-75 L/min
The use of the oxygen flush comes with hazards, including these two potential adverse effects patients may experience.
Barotrauma
Awareness (dilution of gas)
Which flow knob must be fluted and larger than other gases so that it looks and feels different?
The oxygen flow knob
The amount of pressure in the low pressure system should be:
A. Slightly above atmospheric pressure and constant
B. Slightly below atmospheric pressure and constant
C. Slightly above atmospheric pressure and variable
D. Slightly below atmospheric pressure and variable
C. Slightly above atmospheric pressure and variable
Depends on flow from flowmeters and backpressure from breathing circuit
The low pressure system includes:
Flowmeters
Hypoxia prevention devices
Unidirectional valves
Pressure relief devices
Common gas outlet
What kind of tubes are flowmeters?
Describe these tubes:
Thorpe Tubes
Smallest diameter at bottom = increases in diameter as you go up
Free floating indicator (flat on the top)
A stop at the top of tube
The 2nd stage regulator is located in the ___ and maintains a psi of ___ - ___.
The 2nd stage regulator is located in the flowmeters and maintains a psi of 14-30.
Standard requires oxygen flowmeter to be placed on which side of the machine?
Why?
Right Side! (closest to the patient)
If there is an oxygen leak and it was in the 1st or 2nd flow meter position = you lose ALL of the gases
If it is on the far right, a leak in the Nitrous and Air won’t cause a leak in the oxygen.
Which of the following display the safest flowmeter sequence?
C and D
(Oxygen flow meter on the far right)
What are the 2 hypoxia prevention devices in the low pressure system that were highlighted in lecture?
- Mandatory Minimum Oxygen Flow
- Minimum Oxygen Ratio
When the master switch is turned on, the mandatory minimum oxygen flow will provide a minimum flow of ___.
50-250 ml/min
What is the minimum oxygen ratio?
When does this kick in?
Mechanical linkage (ratio) when doing a case with nitrous that prevents us from giving ALL nitrous and no oxygen.
When oxygen concentration drops to 25%
Where are the unidirectional valves located in the low pressure system?
Located between vaporizer and common gas outlet, upstream from the oxygen flush valve.
What do the unidirectional valves aim to reduce?
Lessens back pressure from flush or breathing circuit.
Where are the pressure relief devices located?
(Specifically in the low pressure system)
Near the common gas outlet
Because the pressure relief devices open to the atmosphere and vents if preset pressure is exceeded, it has limited ability for ___.
Jet ventilation
The common gas outlet should not be used to deliver ___.
Why?
Supplemental oxygen
- Delay in emergencies
- Potential delivery of inhalational agents
What is the function of the alternative oxygen control?
Delivers oxygen in case of electronic power failure
Correctly identify the primary location (High, Intermediate, Low pressure system) for all of the following components of the anesthesia machine.
Flowmeters:
Pipeline Inlets:
Cylinders:
Pressure relief valve:
Vaporizer:
Flow Control Valve:
Hanger Yoke:
Flowmeters: Low
Pipeline Inlets: Intermediate
Cylinders: High
Pressure relief valve: Intermediate AND Low
Vaporizer: Low
Flow Control Valve: Intermediate
Hanger Yoke: High
This component of the anesthesia machine is found in all the pressure systems (mostly High and Intermediate):
Check Valves
Which locations in the anesthesia machine are the “Filters” and “pressure gauges” most abundant?
High and Intermediate
In which pressure system is the power outlet, oxygen flush and oxygen pressure alarm found?
Intermediate
