 Tracheal intubation , usually simply referred to as intubation , is the placement of a flexible plastic tube into the trachea ( windpipe ) to maintain an open airway or to serve as a conduit through which to administer certain drugs . It is frequently performed in critically injured , ill , or anesthetized patients to facilitate ventilation of the lungs , including mechanical ventilation , and to prevent the possibility of asphyxiation or airway obstruction . 
