General anesthesia, called general anesthesia, is one of the most important modern anesthesia methods. General anesthesia refers to the state in which the patient enters the blood circulation through intravenous injection or respiratory inhalation, and finally reaches the brain, where the central nervous system is temporarily inhibited, causing the patient to lose consciousness and no pain sensation around the body. The clinical manifestations are mainly the loss of the patient’s consciousness, the disappearance of generalized pain sensation, amnesia, and the inhibition of various reflexes, as well as the use of anesthesia-assisted drugs such as muscle relaxants, which will have a relaxing effect on the skeletal muscles so that the surgeon can easily operate during surgery. The degree of central nervous system depression by anesthetics is related to the concentration of the drug in the blood, and the concentration is strong. When the amount of drugs entering the brain is gradually reduced or completely removed, the mental and various reflexes will gradually return to the state before anesthesia, which means that general anesthesia is reversible.