A device (100, 200, 250) for positive pressure ventilation and continuous positive airway pressure (CPAP) treatment comprising: - a fresh gas flow inlet, arranged to receive a fresh gas flow from a fresh gas flow tube connectable thereto; - a patient interface end, arranged to be connected with a patient interface; - an outlet having an open end; - a variable flow CPAP generator comprising first, second and third connection portions (10, 11, 12), wherein the first connection portion is connected with the fresh gas flow inlet, the second connection portion is connected with the patient interface end, and the third connection portion is connected with the outlet, wherein the device is configured such that a CPAP level generated by the variable flow CPAP generator is adjustable by varying the fresh gas flow to the fresh gas flow inlet and thereby to the variable flow CPAP generator; and - an internal leakage channel arranged to extend between the fresh gas flow inlet and at least one of the patient interface end and the outlet, such to create an internal fresh gas leakage flow there between, bypassing the first connection portion of the variable flow CPAP generator, which internal fresh gas leakage flow is added to the fresh gas flow provided by the variable flow CPAP generator in the PPV mode, characterized in that the internal leakage channel comprises a hole extending through an internal wall portion, which extends between the fresh gas flow inlet and one of the second connection portion, the third connection portion, and a pressure release connection portion, arranged partially in parallel with the second connection portion, and having a first end connected with the patient interface end and a second end connectable with a pressure release tube. - a fresh gas flow inlet, arranged to receive a fresh gas flow from a fresh gas flow tube connectable thereto; - a patient interface end, arranged to be connected with a patient interface; - an outlet having an open end; - a variable flow CPAP generator comprising first, second and third connection portions (10, 11, 12), wherein the first connection portion is connected with the fresh gas flow inlet, the second connection portion is connected with the patient interface end, and the third connection portion is connected with the outlet, wherein the device is configured such that a CPAP level generated by the variable flow CPAP generator is adjustable by varying the fresh gas flow to the fresh gas flow inlet and thereby to the variable flow CPAP generator; and - an internal leakage channel arranged to extend between the fresh gas flow inlet and at least one of the patient interface end and the outlet, such to create an internal fresh gas leakage flow there between, bypassing the first connection portion of the variable flow CPAP generator, which internal fresh gas leakage flow is added to the fresh gas flow provided by the variable flow CPAP generator in the PPV mode, characterized in that the internal leakage channel comprises a hole extending through an internal wall portion, which extends between the fresh gas flow inlet and one of the second connection portion, the third connection portion, and a pressure release connection portion, arranged partially in parallel with the second connection portion, and having a first end connected with the patient interface end and a second end connectable with a pressure release tube.