The ASA is a grading scale developed by the American Society of Anesthesiologists, which classifies patients requiring anesthesia into six grades so that anesthesiologists can decide whether or not anesthesia is needed based on this scale. 1. Level 1: The patient is generally in good health, and the functioning of all organs of the body is relatively normal. 2. Grade 2: Except for surgical diseases, vital organs such as the heart, lungs, brain and kidneys are functioning well with mild complications. 3. Grade 3: Complications of vital organ functions such as heart, lungs, brain and kidneys are serious, physical strength is limited and normal life is possible. 4. Grade 4: The complications of the heart, lungs, brain, kidneys and other vital organs are very serious, and the ability to take care of oneself is lost, and the life is in danger. 5. Grade 5: Regardless of whether or not the patient receives surgical treatment, the patient’s life can hardly be maintained for 24 hours, and he/she is a patient on the verge of death. 6. Grade 6: Brain death is confirmed and the organs are intended to be used for other organ transplantation surgical treatment.