Intubation is the insertion of a tube into the trachea during anesthesia, and its indication is the need for tracheal intubation during general anesthesia. Currently, a mixture of anesthesia is commonly used in clinical practice, including inhalation anesthetic drugs as well as some intravenous anesthetic drugs. Commonly used inhalation drugs, such as sevoflurane and isoflurane, and commonly used intravenous anesthetic drugs, such as the barbiturates etomidate and isoproterenol. So when there is general anesthesia the patient’s muscles will be somewhat relaxed and breathing will depend on the ventilator to provide the prime mover. To avoid respiratory failure of the patient during anesthesia, so the patient is given an airway artificially, that is, tracheal intubation, to ensure that the patient has oxygen supply for all physiological functions. In addition, tracheal intubation is also indicated for aspiration of secretions from the upper airway that block the trachea during anesthesia. Sometimes the regurgitated material in the stomach or bleeding from the gastrointestinal tract can easily be aspirated into the lungs by mistake, causing life-threatening conditions, which can be avoided by tracheal intubation and can facilitate resuscitation in case of emergency.