Clinical Research Directory

Inclusion Criteria: * ASA was classified as I-III * The operation time was less than 120 minutes * Informed consent is signed by all study participants * Elective lower extremity surgery under spinal anesthesia was performed Exclusion Criteria: * Pregnant or lactating women * Patients with Difficult Airways * History of severe neurological and muscular diseases and mental retardation * Patients with severe respiratory and circulatory diseases, including acute heart failure. Unstable angina pectoris. Resting ECG heart rate \<50 beats/min. QTc: ≥470ms in men and ≥480ms in women. Third degree atrioventricular block. Severe arrhythmia. Moderate to severe heart valve disease. Chronic obstructive pulmonary disease. A history of severe asthma. * Abnormal liver and kidney function: ALT and/or AST exceeding 2.5 times the upper limit of the medical reference range * Take diazole drugs and/or opioids in one month or nearly three months * Patients who were allergic to or contraindicated to benzodiazepines, opioids, propofol, flumazenil, naloxone, etc * Patients who could not monitor the depth of anesthesia for various reasons