The present invention relates to a catheter for ventilating a patient, with a ventilation channel 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, mm, and the ventilation channel having an open end, and a connector end for connection to a gas flow reversing element. According to the invention, the catheter is 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, with an open measurement end near the open end of the ventilation channel, and a measurement connector piece for connecting a pressure display device. Of particular advantage is a catheter with an expansion body (cuff) that is fluidically connected to a supply channel through which the expansion body can be increased or reduced in size by means of a fluid. The jet ventilation catheter according to the invention permits a novel ventilation principle that can be regarded as a bridge between classical jet ventilation and conventional controlled ventilation and that opens up possibilities for new and improved interventions in the airways.