右美托咪定（DEX）为αn 2肾上腺素能受体（αn 2-AR）激动剂，除了在围术期应用外，还应用于门诊检查或治疗中。DEX镇静催眠作用的特点和优势在于，患者可进入类似自然睡眠状态，不仅有利于提高镇静效果，且易于唤醒；很少发生下颌松弛，无明显呼吸抑制。DEX的其他优势还在于其抗应激反应和潜在脏器保护作用，以及对认知功能影响小的特点。DEX主要的不良反应为暂时性高血压、低血压、心动过缓等。DEX的另一特点是药效消失相对较慢，术后患者可能发生嗜睡和体位性低血压。必须注意的是，DEX不能独立作为麻醉药在全麻术中担当主要的镇痛药和镇静药，只能发挥辅助作用，其作用有赖于合理的用法和用量，且作用并非是“全”或“无”的，使用过程中须严密监测患者的生命体征。n “,”Dexamethasidine (DEX) is an alpha-2 adrenoreceptor (αn 2-AR) agonist, which is not only used in the perioperative period, but also in outpatient examination or treatment. The characteristics and advantages of sedation and hypnosis with DEX are that patients can enter a state similar to natural sleep, which is not only beneficial to improve the sedation effect, but also easy to wake up, and there is little jaw relaxation and no obvious respiratory inhibition. The additional advantages of DEX lie in its function of anti-stress response and potential organ protection and its little influence on cognitive function. The main adverse reactions of DEX were temporary hypertension, hypotension, bradycardia, and so on. Another characteristic of DEX is the relatively slow disappearance of drug effect. Patients may have drowsiness and postural hypotension after operation. It must be noted that DEX cannot be used as an independent anesthetic in general anesthesia to act as the main analgesic and sedative, but only to play an auxiliary role, which depends on the reasonable use and dosage and is not “all” or “none”. And the vital signs of patients must be closely monitored during the process of DEX application.n