Anaesthesia General e027ce11 The most appropriate circuit for ventilating a spontaneously breathing infant during anaesthesia is – A Jackson Rees modification of Ayres T piece B Mapleson A or Magill's circuit C Mapleson C or Waters to and frocanister D Bains circuit High-Yield Explanation The Ayre's T-piece with Jakson-Rees modification remains the mainstay of pediatric anaesthesia.