Closed suction set is used for who needs suction therapy. Free Trachea Closed Suction Set is classified as tracheobronchial suction catheter that is intended to aspirate liquid or semi-solid matters from a patient’s upper airway. Patients who need to maintain the patency and integrity of the airway and who need to remove accumulated pulmonary secretions. Patients have an ineffective cough and unable to clear the secretion spontaneously.