Clinically, there are two major categories of general anesthesia and regional anesthesia. General anesthesia acts on the brain and is usually used in upper body surgery above the abdominal cavity, such as surgery on the heart, brain, lungs and other vital organs. It is administered intravenously and by inhalation to put a person into a state of general anesthesia, and if necessary, breathing can be controlled by a ventilator. Regional anesthesia acts on the nerve conduction system that conducts stimuli, and is divided into large and small regional anesthesia. The former will make the entire lower extremity unconscious, such as lumbar spinal anesthesia or epidural anesthesia, commonly known as hemianesthesia; the latter has a smaller scope of anesthesia, such as hand nerve anesthesia, which can be performed by nerve block method, i.e., generally speaking, nerve block anesthesia. Pre-anesthesia preparation The anesthesiologist must do two things before administering anesthesia. 1. To understand the patient’s preoperative pathological and physiological conditions by reading the relevant examination, in order to determine the choice of anesthetic drugs and the parameters to be monitored with special attention during surgery. 2, Pre-operative visit to explain the anesthesia process to the patient to relieve the patient’s tension and fear, while allowing the patient to get to know the anesthesiologist and increase mutual trust and support. The preoperative visit helps to collect important information that is not easily detected by the patient, such as whether the patient is an alcoholic or has the habit of taking sleeping pills (such patients are more tolerant of anesthesia and must increase the amount of anesthesia). The choice of anesthesia should be based on the safety and need for the most appropriate and simple method of anesthesia for the procedure. Regional anesthesia has less impact on body functions and can keep you awake during the surgery. Of course, anesthetic drugs can be administered to achieve a controlled drowsiness and reduce the patient’s fear of anesthetic surgery, but this is not the same as general anesthesia. The patient should cooperate with the matters before receiving anesthesia 1. 8 hours before anesthesia should be fasted, any food and beverage can not be drunk, the fasting time for young children can be shortened to 4-6 hours. 2.Patients should take off any external objects such as dentures, braces, glasses, earrings, rings, watches, bracelets, hair clips, necklaces, etc. 3.Please do not wear make-up, so as not to affect the observation of normal skin color. 4. Train to urinate and defecate in bed and breathe deeply. Effective deep breathing and proper coughing can reduce the occurrence of postoperative complications, so training exercises should be done first. 5. Adequate rest before surgery. Postoperative pain relief The postoperative pain stimulation will cause adverse effects on all systems in the body and slow down the recovery of the body, and postoperative pain relief can improve this situation. In the past, meperidine was traditionally administered intramuscularly to provide pain relief by stimulation and nerve excitation, but it has been phased out because of its respiratory depression and addiction disadvantages. Currently, the more advanced method is the continuous injection of anesthetic drugs into the epidural cavity and patient-controlled pain relief. The epidural pain relief method is based on the installation of an indwelling catheter in the epidural cavity and the postoperative administration of morphine analgesics, which acts near the central nervous system and requires a small dose. The patient-controlled method, also known as bedside button pain relief, is administered intravenously, and all pain medications are administered through a programmed machine that is pressed when the pain is felt, and the machine receives the command to administer the medication to relieve the pain. In addition, continuous sacral block is mostly used for postoperative pain relief in children. After the child is anesthetized, long-acting anesthetics are injected from the sacral fissure to the epidural cavity, which starts to work after about 15-30 minutes and lasts for 2-6 hours.