The present invention relates to a catheter (1) for ventilating a patient, with a ventilation channel (2) for alternately delivering and removing air and/or oxygen to and from the patient"s airways, the catheter having a maximum external diameter of at most 6 mm, preferably 1.5 to 4.5 mm, and the ventilation channel having an open end (3), and a connector end (4) for connection to a supply system (19) for expiratory assistance. According to the invention, the catheter is optionally provided with means or elements for measuring the pressure outside the ventilation channel near the open end. The catheter preferably has a pressure measurement channel (5), with an open measurement end (6) near the open end of the ventilation channel, and a measurement connector piece (7) for connecting a pressure display device.
