Aspiration is the process of sucking out secretions from the airway through an aspirator or suction machine to prevent obstruction of the airway. If the operation is improper, such as excessive pressure of aspiration may lead to soft tissue contusion, such as damage to the mucosal wall of the trachea is likely to aggravate bleeding and edema, and even aggravate its inflammatory response. In addition, frequent aspiration may lead to imbalance in the secretion of airway secretions, resulting in the continuous occurrence of foreign body sensation in the airway and causing reflex coughing and coughing. In addition, if aspiration is performed without attention to asepsis it is likely to bring in more pathogens, such as purulent bacterial infections, which will instead aggravate the inflammatory response of the airways.