The Study is Being Conducted to Evaluate the Efficacy and Safety of Dexmedetomidine Hydrochloride Microneedles for Preoperative Sedation in Children

Inclusion Criteria: * Aged 2 years to 6 years (inclusive ), any genders; * Body weight meeting the criteria: * Scheduled to undergo general anesthesia for surgery/procedure * American Society of Anesthesiologists（ASA） I\~II * Provide written informed consent from the legal guardian Exclusion Criteria: * Allergy to any component of the Dexmedetomidine Hydrochloride Microneedle Patch, history of allergy to other sedative drugs, or known allergy to α2-adrenergic receptor-related products or excipients; * Having received other sedative-hypnotic or analgesic drugs prior to randomization, where the time since last dose is less than 7 half-lives; * History of bronchial asthma, chronic respiratory diseases, or other severe respiratory system diseases; * History of neurological diseases such as ischemic encephalopathy encephalopathy, craniocerebral injury, etc., which in the investigator's judgment may affect the evaluation of the investigational product; * History of thoracic, cardiac, or brain surgery; * Presence of large areas of skin damage or skin conditions unsuitable for topical patch application on the inner aspects of both forearms or the outer aspects of both thighs; * Abnormal liver/kidney function test values (ALT or AST \>1.5 times the upper limit of normal \[ULN\], or bilirubin \>1.5 × ULN, or serum creatinine \>1.5 × ULN); * Severe cardiovascular diseases (e.g., fulminant myocarditis, high-grade or third-degree atrioventricular block, sick sinus syndrome, severe arrhythmia, cardiomyopathy, severe pulmonary hypertension, pulmonary atresia, heart failure); * Anemia requiring treatment, as judged by the investigator (hemoglobin \<80 g/L); * Use of highly selective α2 agonists or antagonists prior to randomization, where the time since last dose is less than 7 half-lives; * Participation in another clinical trial (meaning having received an investigational drug or device) within 3 months prior to screening; * Presence of severe psychiatric illness at screening leading to inability or unwillingness to cooperate; * Other situations deemed by the investigator as unsuitable for inclusion.