A cardiopulmonary resuscitation CPR device (100 200 400) for delivering intrathoracic pressure pulses to a subject (290) the device comprising an air pressure generator (110 310 410) for delivering air to the airways of the subject (290) wherein the air pressure generator (110 310 410) is configured to: operate a first mode wherein in the first mode the air pressure generator (110 310 410) generates a first output (412 770a 770b) comprising a first plurality of positive pressure pulses (771) for temporally increasing the subjects intrathoracic pressure to induce compressions of the heart of the subject (290) by increasing the volume of the subjects lungs operate a second mode wherein in the second mode the air pressure generator (110 310 410) generates a second output (414 880) comprising a second plurality of positive pressure pulses for providing an assured airflow to the lungs of the subject (290) and deliver a resulting output (425 986 1086) to the airways of the subject (290) the resulting output being the superposition of the first output (412 770a 770b) and of the second output (414 880) wherein said first plurality of positive pressure pulses (771) have an amplitude greater than 30 mbar and a frequency in a range of 40 240 beats per minute and wherein said second plurality of positive pressure pulses have an amplitude smaller than 30 mbar and a frequency in a range of 3 to 20 cycles per minute.
