Application of Dexmedetomidine Hydrochloride Injection in Anesthesia for Patients Without Tracheal Intubation

Inclusion Criteria: * 1\) 18\~65 years old (including 18 and 65 years old), no gender limit; * 2\) 18 kg/m2 ≤BMI≤30 kg/m2; * 3\) For patients undergoing elective surgery under non-general anesthesia, the expected duration of surgery is ≥30min; * 4\) ASA classification is Ⅰ～Ⅲ; * 5\) After the patient has a full understanding of the purpose and significance of this trial, he/she voluntarily participates in this clinical trial, agrees to contraception during the study period and within 3 days after the study medication, and signs an informed consent Intent. Exclusion Criteria: * 1\) Patients who have received anesthesia or surgery within 7 days before randomization; * 2\) Patients with a history of acute myocardial infarction or unstable angina within 6 months before the screening period; * 3\) Bradycardia (heart rate \<50 beats/min), Ⅱ or Ⅲ degree atrioventricular block (not including Patients with pacemakers) and other severe arrhythmia and heart failure; * 4\) Hypertension patients who are not satisfactorily controlled (systolic blood pressure ≥160 mmHg, and/or diastolic blood pressure ≥100 mmHg), or patients with hypotension (systolic blood pressure \<90 mmHg); * 5\) People with mental system diseases (such as schizophrenia, depression, etc.) or cognitive impairment; Those with a history of epilepsy; * 6\) Those who suffer from bronchial asthma or other severe respiratory diseases; * 7\) Abnormal blood coagulation function (PT prolongation exceeds the upper limit of normal for 3 seconds and/or APTT prolongation exceeds. The upper limit of the normal value is 10 seconds); * 8\) Abnormal liver and kidney function (ALT and/or AST\>2 times the upper limit of normal, total bilirubin\>1.5 Times the upper limit of normal, blood creatinine\>1.5 times the upper limit of normal); * 9\) Those who have used α2 adrenergic receptor agonists or antagonists within 14 days before randomization; * 10\) Those who have used sedatives such as benzodiazepines and barbiturates within 7 days before randomization; * 11\) People with a history of drug abuse, drug abuse and alcohol abuse, among which alcohol abuse is defined as the average daily drinking Liquor exceeds 2 units of alcohol (1 unit = 360 ml of beer or 45 ml of alcohol is 40% white wine or 150 ml wine); * 12\) Those who are allergic to dexmedetomidine, midazolam, fentanyl and other pharmaceutical ingredients or components; * 13\) Women who are pregnant or breastfeeding; * 14\) Those who have participated in other clinical trials within 3 months before randomization; * 15\) The researcher believes that there are any other circumstances that are not suitable for selection.