Alternative breathing systems For Bain-type and circle co-axial systems, perform an occlusion test on the inner tube and check that the adjustable pressure limiting (APL) valve, where fitted, can be fully opened and closed. Correct gas outlet Particular care must be exercised in machines with an auxiliary common gas outlet (ACGO). Incidents of patient harm have resulted from misconnection of a breathing system to an ACGO or misselection of the ACGO [12]. Whenever a breathing system is changed, either during a case or a list, its integrity and correct configuration must be confirmed. This is particularly important for paediatric lists when breathing systems may be changed frequently during a list
