A balloon or cuff is combined with a distally perforated soft plastic tracheal catheter over a wedge in the middle part of the catheter. The catheter is molded from non-pyrogenic thermoplastic material such as polyethylene, polytetrafluorethylene, polypropylene, poly-carbonate or other readily sterilized orientable material which is precurved at its proximate end for insertion percutaneously or is straight for insertion through the mouth and is perforated at its distal end to divert part or all of the ventilating stream passing through the catheter. If improper positioning of the axial outlet in relation to the tracheal lumen occurs, these distal perforations in the straight and precurved species permit air under pressure to be diverted from the axial outlet thereby preventing air embolisms while the air passing through the wedge blows up the balloon to press it against the trachea. These air embolisms occur and are created due only to the diffusion of air into the tissues impinged upon by the high pressure oxygenated gas flow at the axial outlet. At normal flow with proper placement no more than ten to twenty-five percent of the air passes out of the sides and this diversion maintains the desired medial axial positioning of the catheter in the tracheal lumen. This highThis is created cyclically, the wedge diverting pressure from within the catheter to blow up the balloon under the pressure cycle of the ventilator and to permit collapse in the succeeding cycle. When air flow ceases through the wedge of the catheter, the elasticity of the balloon is such as to cause the balloon to collapse and rest against the catheter, thereby providing the function of a cuff. The cuff function of the balloon minimizes retrograde air leak during the inflation cycle.