Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea.
Korean J Pain. 2014 Oct;27(4):313-20. doi: 10.3344/kjp.2014.27.4.313. Epub 2014 Oct 1.
Dexmedetomidine, an imidazoline compound, is a highly selective α2-adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties. In order to minimize the patients' pain and anxiety during minimally invasive spine surgery (MISS) when compared to conventional surgery under general anesthesia, an adequate conscious sedation (CS) or monitored anesthetic care (MAC) should be provided. Commonly used intravenous sedatives and hypnotics, such as midazolam and propofol, are not suitable for operations in a prone position due to undesired respiratory depression. Dexmedetomidine converges on an endogenous non-rapid eye movement (NREM) sleep-promoting pathway to exert its sedative effects. The great merit of dexmedetomidine for CS or MAC is the ability of the operator to recognize nerve damage during percutaneous endoscopic lumbar discectomy, a representative MISS. However, there are 2 shortcomings for dexmedetomidine in MISS: hypotension/bradycardia and delayed emergence. Its hypotension/bradycardiac effects can be prevented by ketamine intraoperatively. Using atipamezole (an α2-adrenoceptor antagonist) might allow doctors to control the rate of recovery from procedural sedation in the future. MAC, with other analgesics such as ketorolac and opioids, creates ideal conditions for MISS. In conclusion, dexmedetomidine provides a favorable surgical condition in patients receiving MISS in a prone position due to its unique properties of conscious sedation followed by unconscious hypnosis with analgesia. However, no respiratory depression occurs based on the dexmedetomidine-related endogenous sleep pathways involves the inhibition of the locus coeruleus in the pons, which facilitates VLPO firing in the anterior hypothalamus.
右美托咪定是一种咪唑啉化合物，是一种高选择性的α2-肾上腺素受体激动剂，具有交感神经阻滞、镇静、遗忘和镇痛作用。为了将微创脊柱手术（MISS）时的患者疼痛和焦虑最小化，与全身麻醉下的常规手术相比，应提供充分的清醒镇静（CS）或监测麻醉护理（MAC）。咪达唑仑和丙泊酚等常用的静脉镇静剂和催眠剂由于不希望的呼吸抑制，不适合俯卧位手术。右美托咪定作用于内源性非快速眼动（NREM）睡眠促进途径发挥其镇静作用。右美托咪定用于 CS 或 MAC 的主要优点是操作者能够在经皮内窥镜腰椎间盘切除术（一种代表性的 MISS）中识别神经损伤。然而，右美托咪定在 MISS 中有 2 个缺点：低血压/心动过缓及苏醒延迟。其低血压/心动过缓作用可通过术中给予氯胺酮预防。未来使用阿替美唑（一种α2-肾上腺素受体拮抗剂）可能使医生能够控制从程序镇静中恢复的速度。MAC 与酮咯酸和阿片类药物等其他镇痛药一起为 MISS 创造了理想的条件。总之，由于其具有清醒镇静继而无意识催眠和镇痛的独特特性，右美托咪定可为接受俯卧位 MISS 的患者提供有利的手术条件。然而，由于右美托咪定相关的内源性睡眠途径涉及对脑桥蓝斑的抑制，从而促进了前下丘脑 VLPO 的放电，因此不会发生呼吸抑制。
