Arrangement comprising a switchable connector and a gas flow reversing element which is suitable for exploiting a gas supply under positive pressure for selectively generating a gas flow from or to a line connector which is connectable to airways of a patient by way of a lumen of the arrangement; wherein the gas flow reversing element is embodied at least as a main piece with a branching piece, wherein the main piece connects a pressure connector for connection to the gas supply with at least one closable outlet opening and the branching piece connects, by way of a first line, the main piece to the line connector, wherein a nozzle is embodied and arranged in the main piece in such a way that a gas flow flowing from the pressure connector through the nozzle to the outlet opening also is able to produce a gas flow through the first line in the direction of the outlet opening in the main piece if the outlet opening is open, wherein the switchable connector is arranged at the branching piece or at the line connector and switchably connects at least a second line of the arrangement to the first line, wherein the switchable connector has at least two switching positions (16, 17), wherein, in the first switching position, the first line is open and the second line is closed such that the gas flow can flow through the switchable connector in both directions along the first line; in the second switching position, if the switchable connector is arranged at the branching piece, the second line is flow-connected via the switchable connector to the line connector and to the lumen, by which the line connector is connectable to the airways of a patient, or, if the switchable connector is arranged at the line connector, the second line is flow-connected to the lumen, by which the line connector is connectable to the airways of a patient; and in the second switching position the first line in the direction to the main piece is closed and the second line is flow-connected via the switchable connector only to the line connector and/or to the lumen, by which the line connector is connectable to the airways of a patient, so that at no point in time the second line is flow-connectable to the main piece. in the first switching position, the first line is open and the second line is closed such that the gas flow can flow through the switchable connector in both directions along the first line; in the second switching position, if the switchable connector is arranged at the branching piece, the second line is flow-connected via the switchable connector to the line connector and to the lumen, by which the line connector is connectable to the airways of a patient, or, if the switchable connector is arranged at the line connector, the second line is flow-connected to the lumen, by which the line connector is connectable to the airways of a patient; and in the second switching position the first line in the direction to the main piece is closed and the second line is flow-connected via the switchable connector only to the line connector and/or to the lumen, by which the line connector is connectable to the airways of a patient, so that at no point in time the second line is flow-connectable to the main piece.