The MultiCircuit System. 2. A study during spontaneous ventilation in awake volunteers using the Mapleson A mode

Mapleson's A and D are the most efficient semiclosed nonabsorbing circuits used for spontaneous and controlled ventilation. A new device, the MultiCircuit System, allows single-lever selection of Mapleson A or D functions, when used with the conventional two hoses or Mera F coaxial circuit attached. In the A mode, in a study performed on awake volunteers, the MultiCircuit System with two hoses performed comparably to the Magill attachment. When coupled with the Mera F circuit as a coaxial system, the MultiCircuit System was less efficient than the Magill, and had a resistance to expiration exceeding 2cm H2O pressure at a gas flow of 30 l/minute.