Question
A 20-year old spontaneous breathing patient undergoing incision and drainage under GA, which of the following is the breathing circuit of choice for spontaneous ventilation?
| A. |
Mapleson A
|
| B. |
Mapleson B
|
| C. |
Mapleson C
|
| D. |
Mapleson D
|
Show Answer
|
Correct Answer » A
Explanation
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|
Mapleson breathing systems are classified based on the arrangement of the:
- Fresh gas flow (FGF)
- Reservoir bag
- Adjustable Pressure-Limiting (APL) valve
Their efficiency depends on whether the patient is breathing spontaneously or is undergoing controlled ventilation.
For spontaneous ventilation, the Mapleson A (Magill circuit) is the most efficient because it requires the lowest fresh gas flow to prevent carbon dioxide (CO₂) rebreathing.
A. Mapleson A (Magill circuit)
- Most efficient circuit for spontaneous breathing.
- Requires fresh gas flow approximately equal to minute ventilation.
- Produces minimal CO₂ rebreathing.
- Commonly used in spontaneously breathing patients during short procedures.
Why Other Options are Incorrect
B. Mapleson B
- Less efficient than Mapleson A for spontaneous ventilation.
- Rarely used in modern anesthesia practice.
- Requires higher fresh gas flow.
C. Mapleson C (Waters circuit)
- Compact version of Mapleson B.
- Requires high fresh gas flow for both spontaneous and controlled ventilation.
- Not the circuit of choice for spontaneous breathing.
D. Mapleson D (Bain circuit)
- Most efficient for controlled ventilation.
- Requires higher fresh gas flow during spontaneous breathing.
- Commonly used during mechanical ventilation.
