The invention relates to a device for immobilizing oxygen-administering tubes in anaesthetized patients, where the corresponding endotracheal tube comprises, on the distal end thereof, a balloon or bag to be placed in the branch of the trachea of the patient, characterised in that a pair of balloons or bags are connected to the endotracheal tube itself, one of them having an omega shape, and the other being spherical and larger, and both being arranged inside the mouth of the patient and being associated with respective valves for the inflation thereof.
