The overall purpose is to improve the patient’s tolerance for anesthesia and safety, and to ensure that the surgery is performed smoothly and the postoperative recovery is more rapid. For ASAI patients, general preparation is sufficient; for ASAII patients, the general condition and function of vital organs should be maintained to enhance the patient’s tolerance for anesthesia to the greatest extent; for III, IV and V patients, in addition to general preparation, special preparation must be made according to the individual conditions. (A) Mental state preparation Most patients have various degrees of ideological concerns before surgery, or fear, or nervousness, or anxiety and other psychological fluctuations, emotional excitement or sleepless nights, resulting in excessive central nervous system activity, anesthesia and surgery tolerance is significantly weakened, intraoperative or postoperative shock is likely to occur. For this reason, we must try to relieve the patient’s anxiety and anxiety before surgery, starting with care, comfort, explanation and encouragement, appropriately clarifying the purpose of surgery, anesthesia, surgical position, and possible discomfort during anesthesia or surgery as appropriate, making specific presentations to the patient in kind language, and talking and explaining to the patient in response to concerns and questions, in order to gain the patient’s trust and obtain full cooperation. For patients who are overly nervous and cannot control themselves, start to take appropriate amount of tranquilizers several days before surgery, give sleep medication at night, and then give appropriate amount of sedative sleep medication before anesthesia in the morning of surgery. (B) Improvement of nutritional status Malnutrition leads to insufficient protein and certain vitamins, which can significantly reduce anesthesia and surgical tolerance. Protein deficiency is often accompanied by hypovolemia or anemia, and the tolerance to blood loss and shock is reduced. Hypoproteinemia is often accompanied by tissue edema, which reduces tissue resistance to infection and affects wound healing. Vitamin deficiency can lead to abnormal nutritional metabolism, which can easily lead to abnormal circulatory function or coagulation function during surgery, and low postoperative resistance to infection, which can easily lead to pulmonary infection complications. In malnourished patients, if there is sufficient time before surgery, nutrition should be supplemented orally as much as possible; if there is not sufficient time, or if the patient cannot or does not want to eat or drink orally, it can be corrected by small amounts of multiple blood transfusions and injections of hydrolyzed protein and vitamins; for those with low albumin, it is better to give concentrated albumin injection. (C) Postoperative adaptive social training Regarding postoperative diet, body position, urination and defecation, incisional pain or other discomfort, as well as the possible need for prolonged infusion, oxygen, gastrointestinal decompression, chest drainage, urinary catheterization and various drains, etc., the clinical significance can be explained to the patient before surgery, as appropriate, in order to obtain cooperation. Most patients are not used to urinating and defecating in bed and need to exercise before surgery. The importance of postoperative deep breathing, coughing and coughing up sputum must be clearly explained to the patient and trained in the correct method of execution. (IV) Gastrointestinal preparation In elective surgery, except for superficial minor surgery using local infiltration anesthesia, all other methods of anesthesia, regardless of the type of anesthesia, require routine gastric emptying, with the aim of preventing intraoperative or postoperative reflux, vomiting, and avoiding accidents such as accidental aspiration, pulmonary infection or asphyxia. The normal gastric emptying time is 4 to 6 hours. Gastric emptying can be significantly slowed down by emotion, fear, anxiety or pain and discomfort. For this reason, adults should generally abstain from drinking and eating for at least 8 hours, preferably 12 hours, before anesthesia to ensure complete gastric emptying; pediatric patients should also abstain from drinking and eating for at least 8 hours before surgery, but breastfed infants can be fed glucose water once 4 hours before surgery. The importance of fasting and fasting must be clearly explained to the patient’s family in order to gain cooperation. (E) Preparation of the bladder The patient should be instructed to empty the bladder before being sent to the operating room to prevent intraoperative bedwetting and postoperative urinary retention; for pelvic or hernia surgery emptying the bladder is beneficial for surgical field exposure and prevention of bladder injury. For critically ill patients or complex major surgery, a catheter should be left in place after induction of anesthesia to facilitate observation of urine volume. (vi) Oral hygiene preparation After anesthesia, general bacteria from the upper respiratory tract are easily carried into the lower respiratory tract, which may cause pulmonary infection complications in the case of low postoperative resistance. For this reason, patients should be instructed to brush their teeth in the morning and evening and rinse their mouth after meals immediately after hospitalization; for those suffering from loose caries or periodontal inflammation, they need to be treated by dentistry. Before entering the operating room, the movable dentures should be removed to prevent them from falling off during anesthesia, or even being accidentally inhaled into the trachea or embedded in the esophagus. (vii) Preparation for transfusion and blood transfusion For moderate surgery or above, the patient’s blood type should be checked before surgery, and a certain amount of whole blood should be prepared for a good cross fit test. Anyone who has water, electrolyte or acid-base imbalance should be routinely transfused before surgery to supplement and correct as much as possible. (H) Examination of therapeutic drugs Patients with complex conditions often have received a series of medications before surgery. In addition to requiring a comprehensive examination of the effects of drug therapy before anesthesia, emphasis should be placed on the interactions between certain drugs and anesthetic drugs, some of which may easily lead to adverse reactions in anesthesia. For this reason, certain drugs should be determined whether to continue with, adjust the dose before or stop using. For example, digitalis, insulin, corticosteroids, and antiepileptic drugs generally need to be continued until preoperative, but the dose should be checked and readjusted. In patients who have been on corticosteroids for a longer period of time a month ago and have stopped taking them before surgery, there is a risk of acute adrenocortical hormone insufficiency, so exogenous corticosteroids must be resumed before surgery until several days after surgery. Patients on anticoagulant therapy should be discontinued prior to surgery and attempts should be made to antagonize their residual anticoagulant effects. Long-term use of certain central nervous system depressants, such as barbiturates, opioids, monoamine oxidase inhibitors, tricyclic antidepressants, etc., may affect tolerance to anesthetics or may induce respiratory and circulatory accidents during anesthesia, so they should be discontinued before surgery. Tranquilizers (e.g. phenothiazines – chlorpromazine), anti-hypertensives (e.g. rooibos – reserpine), anti-anginal drugs (e.g.? receptor blockers), etc., may lead to hypotension, bradycardia, and even cardiac contraction weakness during anesthesia, so they should all be considered for continued use, dose adjustment use, or suspension before surgery.