Method and apparatus for respirating patients, with means for circulating gas in a conduit system, for varying the pressure in the line system, for measuring the gas flow, with connecting means for the patient and supplies for the components of the gas and for withdrawing carbon dioxide, with a first closing device to a discharge line of breathing gas, with in the line system, behind the connecting means to the discharge line a second closing means, and behind that and at a distance there from a third closing means, whilst means are provided by means of which the second and third closing means can be controlled such, that the part of the line system between the second and the third closing means can be closed off, whilst the line system further is provided with means for the generating of a gas flow.
