Semi-closed systems

• Mapleson A: Lack Anesthetic circuit: Lack  , Magill .
• Mapleson D: Bain Anesthetic circuit: Bain .
• Mapleson E: T-piece Anesthetic circuit: Ayre's T-piece .
• Multipurpose Mapleson A, D and E - Humphrey ADE system Anesthetic circuit: Humphrey ADE-circle system.
• These commonly used systems prevent re-breathing of carbon dioxide by the provision of adequate fresh gas flows.
• Mapleson classified these systems in 1957 according to component sequence such as the position of the reservoir bag and exhaust valve as these significantly affect efficiency in both spontaneous and controlled ventilation.
• For spontaneous respiration Mapleson A systems are efficient, while Mapleson D and E systems are much less so.
• The reverse is true for controlled ventilation as Mapleson D and E systems are efficient whereas Mapleson A systems cannot be attached to a ventilator.

Efficiency of Mapleson systems during spontaneous respiration

Efficiency of Mapleson systems during controlled ventilation

Recycling systems using CO2 absorption by soda-lime

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Olikowski C E, Ewart M C, Bingham R M (1991) The Humphrey ADE system: evaluation in pediatric use. Br J Anaesth 66 (2), 253-257 PubMed.
• Byrick R J, Rose D K (1986) Will we ever have a universal anaesthetic breathing system. Can Anaesth Soc J 33 (6), 694-697 PubMed.
• Humphrey D, Brock-Utne J G, Downing J W (1986) Single lever Humphrey A.D.E. low flow universal anesthesia breathing system. Part I - Comparison with dual lever A.D.E., Magill and Bain systems in anaesthetized spontaneously breathing adults. Can Anaesth Soc J 33 (6), 698-709 PubMed.
• Dixon J, Chakrabarti M K, Morgan M et al (1984) An assessment of the Humphrey ADE anesthetic system in the Mapleson A mode during spontaneous ventilation. Anaesthesia 39 (6), 593-596 PubMed.