The most appropriate circuit for ventilating children-

Ans. is 'a' i.e., Jackson Rees modification of Ayre's T piece o Circuit of choice for spontaneous ventilation in adult - Mapleson Ao Circuit of choice for controlled ventilation in adult - Mapleson D (Bain circuit)o Circuit of choice for children - Type F, i.e. Jackson-Rees (first choice) and type E, i.e. Ayre's T piece (second choice)Circuit typeRequired fresh gas flowCommentsSpontaneousControlledType A (Magill circuit)Equal to minute volume(80 ml/kg/min)Very high and difficult to predicto Circuit of choice for spontaneous ventilationo Should not be used for controlled ventilationType B2 x minute volume2 - 2 1/2 minute volume Type C (Water's to and fro)2 x minute volume2 - 2 1/2 minute volumeo It is a coaxial systemType D (Bain circuit)2 - 3 x minute volume1 - 2 x minute volumeo Circuit to choice for controlledo Most commonly used circuit,o Can also be used for spontaneous ventilation.Type E (Ayre's T-piece)2-3 x minute volume3 x minute volumeo Circuit of 2nd choice in childrenType F (Jackson-Rees circuit)2-3 x minute volume2 x minute ventilationo Circuit of choice in childrenNote:- Coaxial system means both fresh gas tube and exhaled gas tube are placed in same axis, i.e., coaxial. Fresh gases are delivered through inner tube and exhaled gas are expired through ofter tube so that mixing of fresh gases and exhaled gases does not occur.