A tracheal coupling for interfacing between a patient and a gases source, the connector comprising a patient port (33) for connecting to the trachea interface/insert, an outlet port (36), and inlet port (31) between patient port and outlet port for receiving a flow of gases from the gases flow source, the connector restricting expiratory flow in use to produce PEEP of at least 1 cm H2O when flow to the inlet port is 50 liters per minute. A system or method for supplying gases to a patient using the connector is also disclosed. Flow restriction is implemented using an orifice that can be adjustable, jetting or turbulence induced by a directed flow nozzle (30). PEEP can also be varied by flow control of gas source.