Anesthesia Circuits

Fig. 79.1
Breathing systems

Breathing System Questions

  1. 1.

    Identify the breathing systems labeled above as 1–5.


  2. 2.

    By what names are Mapleson systems also known as?


  3. 3.

    Name the components of the Mapleson breathing system?


  4. 4.

    What are the advantages of the Mapleson A system and how does it work?


  5. 5.

    Are there disadvantages of the Mapleson A system?


  6. 6.

    What are the advantages and disadvantages of the Mapleson D system?


  7. 7.

    What is the hardest system to scavenge anesthetic gases?


  8. 8.

    Are there advantages and disadvantages of the Mapleson F system?


  9. 9.

    What are the advantages and disadvantages of the circle system?



  1. 1.

    They are Mapleson systems A, D, E, and F and the circle system (see Fig. 79.1)[15].


  2. 2.

    Mapleson systems are also known as carbon dioxide washout [depend on fresh gas flow (FGF) to wash out carbon dioxide] or flow-controlled breathing systems.


  3. 3.

    Components of the Mapleson breathing systems are (1) fresh gas flow, (2) breathing tube (corrugated for flexibility and kinking resistance), (3) mask, (4) reservoir bag (antistatic or low charged, monitors respiration, accommodates fresh gas flow during expiration, protects from excessive pressure generation), (5) connectors (increase dead space and resistance), (6) adaptors, and (7) adjustable pressure-limiting (APL) expiratory valve (spring-loaded adjustable one-way valve, and also known as pop-off valve, exhaust valve, overspill valve, pressure relief valve, scavenger valve, and expiratory valve).


  4. 4.

    The Mapleson A system is best for spontaneous respiration with the advantage of less waste of fresh gas flows. The APL valve is open during spontaneous respiration. Fresh gas flows equaling minute ventilation (75–100 ml/kg/min) are required for maximal efficiency. Higher fresh gas flows than minute ventilation will force alveolar gas to be vented, whereas lower fresh gas flows than minute ventilation will allow for rebreathing of alveolar gases to occur. Once the reservoir bag is full of fresh gas flow, the APL valve opens and the alveolar gas is vented [3].

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Sep 23, 2017 | Posted by in Uncategorized | Comments Off on Anesthesia Circuits

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