Exam 2 Breathing Systems: Part 2 (6/24/24) Flashcards
Why are Mapleson Circuits thought to be mostly obsolete?
They do not have a CO2 absorber
Components of Mapleson Circuits:
- Reservoir Bag (Not all of them)
- Corrugated Tubing (Not all of them)
- APL Valve (Not all of them)
- Fresh Gas Inlet
- Patient Connection
What is missing in the Mapleson Circuits?
CO2 Absorbers
Unidirectional valves
Seperate inspiratory/expiratory limbs
What determines how much rebreathing occurs in the Mapleson Circuits?
Fresh Gas Flow
How would we know if CO2 is being rebreathed while using a Mapleson Circuit?
Monitor ETCO2
Location of FGF entrance and APL valve in a Mapleson A (Magill’s System)?
FGF enters near reservoir bag (opposite of the pt.)
APL is near the pt.
In regard to efficiency, what kind of ventilation is the Mapleson A circuit the best and worst at?
Best: Spontaneous
Worst: Controlled
Rebreathing will occur while using a Mapleson A during controlled ventilation unless the FGF is greater than ___.
> 20 L/min
Location of APL valve, FGF inlet and reservoir bag in a Mapleson B?
APL and FGF inlet are near pt
Reservoir Bag is at the end of the system
The Mapleson C is almost identical to the Mapleson B, but the ____ is omitted.
Corrugated Tubing
Compare the efficiency of the Mapleson C to Mapleson A with spontaneous ventilation:
How does the expiratory pause change the efficiency?
Mapleson C is almost as efficient as Mapleson A.
If expiratory pause is longer, this circuit becomes less efficient
The Mapleson C closely resembles a ___.
Ambu Bag
Used for emergency resuscitation
Location of the Reservoir Bag, APL and FGF inlet in a Mapleson D?
Reservoir at the end
APL near reservoir
FGF inlet near pt.
This Mapleson circuit does not have a reservoir bag or an APL valve:
Mapleson E (Ayre’s T-Piece)
The Mapleson E circuit is preferred in this population:
Why?
Preferred in Pediatrics:
There is a decreased amount of resistance
What is the modification made to the Mapleson E that makes it a Mapleson F (Jackson Rees)?
Addition of a Reservoir bag with a hole at the end
Select the 2 correct systems:
Significant amounts of fresh gas is vented through pop-off at end expiration :
Mapleson A
Mapleson B
Mapleson C
Mapleson D
Mapleson E
Mapleson F
Mapleson B
Mapleson C
Select the 3 correct systems:
FGF drives exhaled alveolar gas away from pt:
Mapleson A
Mapleson B
Mapleson C
Mapleson D
Mapleson E
Mapleson F
Mapleson D
Mapleson E
Mapleson F
Rank the efficiency of the Mapleson Circuits from Most efficient to least efficient for spontaneous ventilation:
- Mapleson A
- Mapleson D, F, E
- Mapleson C, B
Rank the Mapleson circuits from most efficient to least efficient for controlled ventilation:
- Mapleson D, F, E
- Mapleson C, B
- Mapleson A
Which Mapleson circuit is termed “Obsolete”?
Mapleson B
This Mapleson Circuit is the most efficient system for controlled Ventilation:
Mapleson D
This Mapleson circuit is used in spontaneously breathing pts to deliver O2:
Mapleson E
Advantages of Mapleson Circuits:
- Simple, inexpensive, and lightweight
- Changes in FGF composition result in rapid changes in the circuit
- Low resistance to gas flow
- No toxic products d/t lack of CO2 absorbent
- No degradation w/ Volatiles
A couple disadvantages to using Mapleson circuits is that they require ___ and are not suitable for patients with ___.
Require high FGF
Not suitable for Malignant Hyperthermia patients
All of the Mapleson circuits have a challenge with scavenging except for ___.
Mapleson D
Rules to prevent rebreathing in a Circle System
Where must the unidirectional valves be located on both the inspiratory and expiratory limbs?
Between the patient and the reservoir bag
Rules to prevent rebreathing in a Circle System
Where must the Fresh gas flow inlet NOT enter the circuit at?
Between the patient and the Expiratory Valve
Rules to prevent rebreathing in a Circle System
True or False:
The APL valve must be located between the pt and the inspiratory valve
False:
APL valve cannot be located between the pt and the inspiratory valve
In a circle system these 2 things are dependent upon the Fresh Gas Flow:
The extent of rebreathing
Conservation of exhaled gases
Describe the function of a circle system in a “Semi-Closed” circuit:
“Contemporary system”
Partial rebreathing occurs but some waste flow is vented through APL or waste gas valve of ventilator
Example of a semi-closed circuit for a circle system:
What does this mean?
Low Flow Anesthesia:
- FGF is less than Minute ventilation
- 50% of expired gas is rebreathed after CO2 removal