Exam 3- Anesthesia Machine I (7/11/23) Flashcards
What group oversees the standards of the anesthesia machine?
- American Society for Testing and Materials
What should the anesthesia machine do?
- Provide accurate and safe gas delivery
- Provide a means for ventilating patients
- Provide electrical outlets
- Provide a housing for monitoring devices
- Provide storage/shelving
What features of the anesthesia works if the Master Switch is OFF?
- Battery charger
- Electrical outlets
- Oxygen flush valve is active
What is the best way to save power on your ventilator if you lose power during an operation?
- Switch from control ventilator to manual ventilation
What are the electrical outlets on the anesthesia machine used to power?
- Anesthesia monitors
- Other appliances should be plugged into hospital’s main outlets
- If requirements exceed outlet; circuit breaker will activate
What are the 3 parts of the pneumatic system?
- High Pressure
- Intermediate Pressure
- Low Pressure
The high-pressure system receives gas from the _______ at high variable pressure.
- Cylinders
The pressure needs to be reduced to a lower, more constant pressure suitable for use in the anesthesia machine
What is the purpose of the Hanger Yoke?
- Orients and support the cylinder
- Provide a gas-tight seal
- Ensures unidirectional flow
It is required to have one hanger yoke for oxygen and one hanger yoke for nitrous
What are the parts of the Hanger Yoke?
- Body- principal framework
- Retaining screw- tightens cylinder (clamp)
- Nipple- thru which gas enters the machine
- Index pins- prevents attaching an incorrect cylinder (PISS)
- Washer- forms seal between cylinder and yoke
- Check valve assembly- ensure unidirectional flow
What is the purpose of the check valve assembly of the hanger yoke?
- Ensures unidirectional flow
- Prevent gas from exiting the machine when there is no cylinder in the yoke
- Prevent gas from being transferred from a cylinder with higher pressure to one with lower pressure
How do cylinder pressure indicators work?
- The Bourdon gauge consists of a tube bent into a coil or an arc.
- As the pressure in the tube increases, the coil unwinds/straightens.
- A pointer connected to the end of the tube can be attached to a lever and a pointer calibrated to indicate pressure.
Gauge required to be calibrated to kPa or psi
What is the purpose of pressure regulators?
- Reduce high, variable pressure in cylinders to lower constant pressure for the machine.
- One pressure regulator must be present for each cylinder
Pressure regulators are also called reducing valves
What were the components of the high-pressure system?
- Cylinder
- Hanger Yoke
- Bourdon Gauge
- Pressure Reducing Valve
Where does the intermediate system get its pressure from?
- Receives pressure from the cylinder, specifically the psi regulator (45 psi)
- Receives pressure from the pipeline (50-55 psi)
What is the intermediate pressure system pressure if the master switch is OFF?
- 0 mmHg
What is included in the intermediate pressure system?
- Pneumatic part of the master switch
- Pipeline inlet connections
- Piping
- Oxygen pressure failure devices
- Oxygen flush valve
- Flow control valves
What is the pipeline inlet connection?
- The entry point for gases from the pipelines.
Pipeline inlet connects are fitted with a diameter index safety system (DISS)
The anesthesia machines are required to have pipeline inlets for what gases?
- Required: Oxygen and Nitrous
- Most also have air
What will prevent the anesthesia machine gas from returning to the pipeline?
- Unidirectional check valve
Where is the pipeline pressure indicator located?
- Found on the front of the anesthesia machine
Picture next to the pressure indicator signifies whether gas is from the pipeline or cylinder.
The piping connects the components inside the machine and must be able to withstand ______ times the intended pressure.
- 4 times (about 200 psi)
Leaks must not exceed __________ ml/min inside the anesthesia machine.
- 25 ml/min
How does the oxygen failure safety device work?
- If O2 pressure is reduced to 30 psi, other gases like nitrous will decrease or discontinue to maintain at least 19% O2 concentration at the common gas outlet.
Oxygen failure alarm will sound within 5 seconds
What two places does the oxygen flush get its supply?
- Receives oxygen from pipeline inlet
- Receives oxygen from cylinder pressure regulator
What are the standards for the oxygen flush?
- Must be operable with 1 hand
- Single purpose
- Self-closing
- Designed to minimize accidental use
- Have flow between 35-75 L/min (can cause barotrauma)
What are the hazards of using the oxygen flush?
- Barotrauma
- Awareness
What is the function of the flow adjustment control?
- Regulate the flow of oxygen, air, and other gases
What is unique about the oxygen flow knob?
- It must be fluted and larger than other gases (looks and feels different)
What are the components of the low-pressure system?
- Flowmeters
- Hypoxia prevention devices
- Unidirectional valves (within the machine)
- Pressure relief devices
- Common gas outlet
The low-pressure system is downstream of ___________.
- flow control devices (knobs)
What indicates the rate that gas passes through?
- Flowmeter
Thorpe tube design, small diameter at the bottom, wider at the top
What is the flowmeter sequence?
- Normal gas flow bottom to top
- Left to right
The standard requires __________ flowmeter to be placed on the right side.
- Oxygen
By having the O2 flowmeter on the right, there is the least chance of leaking and being hypoxic.
What are the hypoxia prevention devices?
- Mandatory Minimum Oxygen Flow
- Minimum Oxygen Ratio
The mandatory minimum oxygen flow is _______ ml/min.
- 50 to 250 ml/min
Master switch needs to be ON for mandatory minimum oxygen flow to work.
What is the minimum oxygen ratio?
- Gas ratio between oxygen and nitrous
- Link engages when oxgyen concentration is 25%.`
Where are the unidirectional valves located in the low-pressure system?
- Located between the vaporizer and common gas outlet.
The low-pressure unidirectional valves are upstream (before) from the _________ valve.
- Oxygen Flush
Theses unidirectional valves will lessen the back pressure from flush or breathing circuit
What is the drawback to the pressure relief valve of the low-pressure system?
- Limits the ability of the machine to provide adequate jet ventilation
The common gas outlet should not be used for __________.
- Supplemental oxygen
This can cause delay in emergencies and cause potential delivery of inhalation agents.
What component receives all gases from the machine and delivers the mixture to the circle system?
- Common gas outlet
What can deliver oxygen in case of an electronic power failure?
- Alternate Oxygen Control
If you press this button, everything shuts off but this oxygen back up supply.
