How is anesthesia classified and how do I choose? Clinical anesthesia methods are broadly classified into five categories: (1) Acupuncture anesthesia: stimulation at certain acupuncture points or specific areas of the body to achieve analgesic effects. Some people consider it not to be a category of anesthesia. (2) General anesthesia: The use of anesthetic drugs to temporarily suppress the functions of the patient’s central nervous system and produce a state of anesthesia. There are three forms of general anesthesia: general anesthesia by inhalation through the nose and mouth, intravenous input and preoperative medication to sedate the patient or deep sleep. (3) Intraspinal anesthesia: commonly known as hemianesthesia. Drugs are injected into the subarachnoid space or epidural space to temporarily anesthetize the nerves leading to the surgical site and provide analgesia. The patient is awake after the anesthesia and can even feel the surgery being performed by the surgeon. (4) Local anesthesia: The drug is injected around the incision or sprayed on the mucosal surface to temporarily block the nerves in a certain area of the body, which has the characteristics of simplicity, safety, quick onset, rapid disappearance of the drug effect and small side effects. (5) Complex anesthesia: As the name implies, multiple drugs or anesthesia methods are used simultaneously. This method can selectively control the effect of drugs, better play the effect of drugs and reduce adverse reactions. Anesthesia is required to be safe and effective, to minimize the patient’s pain and to maintain the patient’s normal physiological function under the premise of active cooperation with surgery. Therefore, the choice of anesthesia must be based on the patient’s physical condition, age, disease, surgical method and requirements for anesthesia, available equipment and drugs, and the technical level of the anesthesiologist. This is because during the operation, the surgeon concentrates on the operation and the patient’s vital signs are monitored and adjusted by the anesthesiologist. The anesthesiologist brings the patient to the state of anesthesia through the operation of anesthesia itself, and constantly observes the changes in blood pressure, pulse, respiration and peripheral circulation during the operation, analyzes the changes in the condition at any time, adjusts the drugs according to the patient’s degree of response to the anesthetic drugs or adverse reactions, and meets the requirements of the operation with minimal physiological disturbance of the patient. During surgery, they also work with the operating room nurses to manage the transfusion of blood and fluids, appropriately regulate the rate and dosage of fluids, and correct circulatory disorders and disorders of water-electrolyte balance. The anesthesiologist will also escort the patient back to the ward after surgery, check blood pressure, pulse and respiration, and hand over to the ward duty staff before leaving. Why is it important for the anesthesiologist to see the patient before surgery? The day before surgery, the anesthesiologist will visit the patient in the ward to understand the patient’s general condition, laboratory results and the intended surgery, estimate the patient’s physical and mental status, ask about the patient’s previous history of surgical anesthesia and drug allergies, and develop a general anesthetic plan based on the above. The patient will also be asked about the medications he or she has taken recently to determine if there are any medications that are potentially dangerous and contraindicated for anesthesia, especially general anesthesia, such as compound antihypertensive tablets, corticosteroids, monoamine oxidase inhibitors and certain sedatives, and if they are taken, appropriate measures should be taken to avoid potentially dangerous episodes under the influence of surgery by even stopping the surgery. Finally, the anesthesiologist explains to the patient and his family the purpose of anesthesia, the way of anesthesia, what accidents may occur in anesthesia and what consequences there are, so that the patient’s family is prepared for certain thoughts, and obtains the consent of the patient himself, his family and his unit by signing to dispel the patient’s or his family’s doubts, so that the patient feels informed and happily accepts anesthesia and surgery. Does general anesthesia have any effect on the brain? Most of the higher centers of the body’s sensory, motor, emotional and intellectual abilities are located in the cerebral cortex and the subcortical neurofunctional areas. General anesthesia is a temporary suppression of the brain to achieve pain relief or even loss of consciousness, which will have some effects on brain cells, but this is reversible. When the drug is excreted from the body and broken down in the body, the effect of the drug disappears, and the patient gradually wakes up without leaving any after-effects, and the morphological structure of brain tissue does not change in any way. Therefore, the fear that general anesthesia will make people stupid is not necessary. It is very rare for a patient to have brain cell damage due to excessive general anesthesia. Are there any risks of anesthesia and what are the complications and accidents The risks of anesthesia are the complications and accidents during anesthesia. Any anesthesia or surgery is a foreign invasion to the patient, and its drug effects and the operation itself have various effects on the patient’s organs: ① Allergic reactions to anesthetic drugs. ②The direct effect of anesthesia decreases ventilation and respiration, and sometimes even causes respiratory arrest, which needs to be controlled by artificial respiration; anesthesia also has different inhibitions on the heart and brain, reducing their activities; anesthetic drugs have to be detoxified, metabolized and excreted through the liver and kidneys, which also have effects on them. ③Anesthesia-induced hypoxia and hypotension can also have a negative effect on the systemic organs. ④Infection, catheter breakage, and airway obstruction due to operation. In addition, different anesthesia methods may cause different complications. For example, nausea and vomiting, postoperative headache, hypotension, and low back pain are associated with lumbar anesthesia; respiratory obstruction, pulmonary complications, blood pressure changes, and fever are associated with general anesthesia. There may also be some unpredictable conditions in anesthesia, which may be related to individual patient differences, although rare, but like penicillin allergy can cause damage to the patient. Nevertheless, these impairments are rare and mostly transient and can be recovered quickly. The risks of anesthesia are decreasing with the continuous improvement of techniques and equipment.