A device for use with an apparatus for providing agitation inside a patient's body cavity filled with a therapeutic fluid (F) is presented, said apparatus comprising: a gas source (6, 7); an inlet tube (4) for delivering gas (G) from the gas source into a patient's body cavity (C); and an outlet tube (5) for recovering gas from the patient's body cavity; such that substantially all the fluid and/or content present in the body cavity is agitated; wherein the device further comprises at least a chamber (10) for receiving the fluid and gas recovered from the patient's body cavity and the chamber comprises at least one inlet port (11) for recovering fluid and gas from the patient's body cavity.