Assembly comprising an instillation catheter and a connector (1) for attachment to a tracheal or endotracheal tube has a distal end (1a) attached to the tube and a proximal end (1b) attached to a respirator. It has a branch (5) for inserting the catheter, and contains a valve (2) with an opening made of elastically deformable material that can be opened by inserting the catheter and a distal nose section with a normally closed slit at its tip. An independent claim is also included for a valve as above.
