By interposing an adapter between the endotracheal or tracheal tube inserted to a patient and the ventilation and suction systems that are connected to the endotracheal tube, a catheter could be inserted via an input port built into the adapter so as to enable a medical personnel to provide localized treatments in the lungs of a patient without having to disconnect either one of the systems connected to the endotracheal tube. The adapter is configured to have a securing mechanism that allows the medical personnel to secure the medication catheter in place. A one way valve fitted to the apertured arm that forms the input port of the adapter prevents any back flow of fluid from the input port. The catheter is manufactured with calibration markings, most likely equally spaced, and a radiopaque line along its length to enhance the maneuvering and the positioning thereof in the patient so that the distal tip of the catheter could be accurately positioned to the desired location of the patient's tracheal/bronchial tree. As a result, the localized treatment such as the injection of a medicament is accurately provided to the appropriate location where the need is the greatest.