Compressible bag 11 which is manipulated by an anaesthetist to control the breathing of a paediatric patient to whom mask 32 is applied, is disposed within a collector dish 12 so that exhaled breath and excess anaesthetic gas can be aspirated away by way of a coupling tube 19 connected to an exhaust duct 26, thereby to avoid pollution of the atmosphere with anaesthetic gas. The dish 12 has a half lid 16 permitting access to the bag 11. <IMAGE>
