General introduction: The resection of lesions in functional areas of the brain (language and motor areas) is a difficult problem in neurosurgery. Traditionally, these surgeries are performed under general anesthesia, and the variation in the location of functional brain areas caused by individual differences and the nudging effect of lesions makes it difficult for the surgeon to make an accurate determination of the functional brain areas intraoperatively, which can easily cause postoperative language, motor and sensory dysfunction and reduce the quality of postoperative survival of the patient, as well as impose a burden on the family and society. In recent years, intraoperative wake-up general anesthesia techniques have gradually gained the attention of neurosurgeons and anesthesiologists. By waking up the patient intraoperatively and using neuronavigation and neurophysiological techniques for intraoperative anatomical and functional localization of brain tissue while the patient is awake, in order to monitor possible brain functional area damage in real time while removing the tumor and maximize the protection of brain function, is a new strategy for current brain functional area surgery. One study reported that the total resection rate of functional brain area surgery under anesthesia wake state reached 83,3% and the secondary resection rate reached 16,7%, and 100% of the postoperative period was free of serious motor, sensory and language dysfunction. Another study reported that in 28 cases of functional brain area surgery under arousal anesthesia, only one case showed aggravation of postoperative aphasia, and the remaining 27 cases showed no obvious deterioration of neurological dysfunction after surgery. The difficulties of intraoperative arousal are: the patient is fully awake during the neurological test and can cooperate with the operator to complete the instructions; the patient is prone to agitation if the analgesia is not sufficient during the awake period; excessive analgesia leads to respiratory depression and hypercapnia; the patient has difficulty in opening the airway due to the surgical position, etc. It is a difficult problem for anesthesiologists to ensure the safety of anesthesia for such patients, and at the same time to make the patients pass smoothly and quickly between the states of “sleep-wake-sleep”. This project uses the latest Supreme mask to maintain mechanical ventilation during anesthesia, and lidocaine cream is applied to the mask surface beforehand to reduce the patient’s discomfort in the throat during awakening. Intraoperatively, multimodal analgesia was used, i.e. general anesthetics with rapid and complete metabolism, long-acting local anesthetic infiltration of the scalp and dura mater, and a combination of analgesics with different mechanisms of action, such as remifentanil and tramadol. After discontinuation of the anesthetic drugs, the patient was rapidly awakened and the mask was removed. The problems of agitation, respiratory depression, circulatory instability, intracranial hypertension, and difficulty in tracheal intubation during reanesthesia due to pain and discomfort of the patient during previous awakenings were solved. The method and the drugs used cause little interference with electrophysiological monitoring. Implementation steps: Patients undergoing craniotomy who require intraoperative arousal for lesions in the functional brain area of neurosurgery in our hospital were selected. Exclusion criteria: ①Patients operated in prone position; ②Patients with severe liver and kidney dysfunction and cardiopulmonary disorders; ③Patients with possible difficult airway (e.g., patients who are overly obese and have sleep apnea syndrome in combination). Anesthesia method: In addition to routine ECG monitoring, direct arterial pressure was monitored by radial artery puncture under local anesthesia and end-expiratory carbon dioxide (PetCO2) and electroencephalographic bifrequency index (BIS) monitoring were performed after the patient was admitted. Anesthesia was induced with propofol and remifentanil, and a Supreme laryngeal mask coated with lidocaine cream was inserted when the patient lost consciousness and the BIS value was maintained between 40 and 60. Mechanical ventilation was used to maintain respiration, and propofol and remifentanil were continuously infused and sevoflurane was inhaled to maintain anesthesia with a BIS between 40 and 60. No inotropic agents were used during the entire anesthesia. The surgical position was lateral, with the head fixed in a cephalic frame and moderate posterior tilt, and local infiltration anesthesia was performed with a long-acting local anesthetic, 0.25% ropivacaine, around the fixed head stud, the surgical incision and the base of the flap. After opening the skull flap, tramadol 1mg/kg was injected intravenously, and a large cotton sheet infiltrated with local anesthetic was covered on the dura mater for 5min, and the dura mater was cut open, while the inhalation of sevoflurane was stopped and the infusion of isoproterenol and remifentanil was stopped. The mask was removed after the patient’s tidal volume was normal and consciousness and orientation were restored. Electrical cortical stimulation was performed to find and localize the functional cortex. After resection of the intracerebral lesion, the Supreme mask was placed after induction of anesthesia with isoproterenol and remifentanil to relieve the patient’s discomfort during cranial closure, and anesthesia was maintained until the end of the operation. The Supreme mask is a new type of disposable mask based on the principle of esophageal drainage mask, which is easier to insert and more precise in alignment due to its unique pre-shaped design conforming to the physiological curvature of the oropharynx. It has less hemodynamic impact during insertion and extraction. 2. The application of multimodal analgesia to intraoperative wake-up anesthesia has enriched the connotation of multimodal analgesia. For example, the application of lidocaine cream on the surface of Supreme mask, the combination of fast-metabolizing general anesthetics and long-acting local anesthetics, and the combination of analgesic drugs with different mechanisms of action such as remifentanil and tramadol are all innovations of this project.