Exam 2- Breathing Systems II (6/27/23) Flashcards
What is a Mapleson Circuit?
- The Mapleson Circuit Systems are used for the delivery of oxygen and anesthetic agents and the removal of carbon dioxide
How many types of Mapleson Circuits are there?
- Six Types (A → F)
What are the components of the Mapleson Circuit?
- Patient connection/Facemask (Patient end)
- Reservoir bag (operator end)
- Corrugated tubing
- APL valve (variable positioning)
- Fresh gas inlet (variable positioning)
What components are absent in all Mapleson Circuit Systems?
- CO2 absorber
- Unidirectional Valves
- Separate Inspiratory and Expiratory Limbs
What is another name for the Mapleson Circuit Systems?
- Carbon Dioxide Washout Circuits
- Flow-controlled Breathing Systems
How does the Mapleson Circuit System prevent rebreathing without a CO2 absorber?
- FGF must be significantly greater than minute ventilation to “washout” the CO2.
What is another name for Mapleson A?
- Magill’s System
Where does fresh gas flow enter in the Mapleson A circuit?
Where is the APL valve located in the Mapleson A circuit?
- FGF enters from the operator end, near the reservoir bag
- APL valve located on patient end
Of all the systems, what is Mapleson A best at?
What is Mapleson A the worst at?
- Best efficiency of all systems for spontaneous ventilation
- Worst efficiency of systems for controlled ventilation
Mapleson A Circuit:
What is vented out from the APL valve in spontaneous ventilation during expiration?
- Dead space gas (yellow)
- Alveolar gas (red)
Mapleson A Circuit:
What is vented out from the APL valve in controlled ventilation during expiration?
- APL valve does not open
Mapleson A Circuit:
What is vented out from the APL valve in controlled ventilation during inspiration?
- Mostly fresh gas (blue)
- Some alveolar gas (red)
- Increase the risk of rebreathing alveolar gas (red)
Where are the APL Valve and Fresh gas inlet located in the Mapleson B Circuit?
- APL and FG inlet located near the patient
Why is the Mapleson B Circuit considered inefficient and obsolete?
- Significant fresh gas is vented through APL during exhalation
- Blue (FGF)
- Red (alveolar gas)
FGF should be ______ times the minute volume during spontaneous and controlled ventilation to prevent rebreathing in the Mapleson B circuit.
- FGF should be 2x minute volume
Where are the APL Valve and Fresh gas inlet located in the Mapleson C Circuit?
- APL and FGF located near the patient
Mapleson C is identical to Mapleson B except for what specific difference?
- Omission of the corrugated tubing
How much FGF is needed for the Mapleson C circuit to prevent rebreathing?
- FGF needs to be 2x minute volume to maintain efficiency
When are Mapleson’s C circuits usually used?
- Emergency resuscitation
Where are the APL Valve and Fresh gas inlet located in the Mapleson D Circuit?
- APL valve is located near the reservoir bag
- FGF inlet is located near the patient
Which circuits are known to have “T-modifications” or are known as the “T-group”?
- Mapleson D
- Mapleson E
- Mapleson F
Which circuit is the MOST efficient for controlled ventilation?
- Mapleson D
What kind of valve can be added to Mapleson D circuits?
- PEEP Valve
FGF rate should be _______ times minute ventilation in Mapleson D circuits.
- 2 to 2.5 times
What circuit is a modification of Mapleson D?
What is modified?
- Bain Circuit
- Fresh gas flows through a narrow inner tube (coaxial) nested within the outer corrugated tube.
- The central fresh gas tubing enters the corrugated hose near the reservoir bag, but the fresh gas actually empties into the circuit at the patient’s end. Exhaled gases pass down the corrugated hose, around the central tubing, and are vented through the pop-off valve near the reservoir bag.
- Exhaled gases passing down the outer corrugated hose add warmth to the inspired fresh gases by countercurrent heat exchange.
What is another name for Mapleson E?
- Arye’s T-piece
What is missing in the Mapleson E circuit?
- No reservoir bag
- No APL valve
Where does FGF enter the Mapleson E circuit?
- Near the patient
What forms the reservoir if there is no Reservoir Bag on the Mapleson E circuit?
- Corrugated Tubing
What patient population is the Mapleson E circuit designated for?
- Spontaneous breathing pediatric patients to deliver O2
- Age: Less than 5 years
- Weight: Less than 20 kg
How would you increase the pressure of the Mapleson E circuit without an APL valve?
- Occluding the end of the corrugated tubing
What is the other name for the Mapleson F circuit?
- The Jackson Rees Circuit
What is missing in the Mapleson F circuit?
- No APL Valve
Where is the FGF inlet on the Mapleson F circuit?
Where is the Reservoir Bag on the Mapleson F Circuit?
Is there anything special about the Reservoir Bag on the Mapleson F Circuit.
- FGF inlet near patient
- Reservoir Bag on the operator side
- Reservoir Bag is open
How can pressure be generated in the Mapleson F Circuit?
- The reservoir bag hole may be occluded by the operator’s hand to control bag distension and pressure or fitted with a pop-off or PEEP valve for more precise control.
What does the reservoir bag on the Mapleson F circuit allow?
- Allow for easy tactile and visual monitoring of the patient’s respiratory effort.
What is the FGF rate for the Mapleson F circuit?
- 2-2.5 x minute ventilation
Improved rebreathing efficiency is due to what factor?
- Location of the pop-off valve relative to FGF
FGF located near patients will experience less rebreathing.
Which Mapleson Circuits will experience significant amounts of fresh gas vented through pop-off at end-expiration?
- Mapleson B
- Mapleson C
Which systems have FGF drives that drive exhaled alveolar gas away from pt
- Mapleson D
- Mapleson E
- Mapleson F
Rank the groupings of the Mapleson Circuit in efficiency for spontaneous ventilation.
- Mapleson A
- Maplesons DFE
- Maplesons CB
Rank the groupings of the Mapleson Circuit in efficiency for controlled ventilation.
- Maplesons DFE
- Maplesons BC
- Mapleson A