Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, 02114, USA.
Curr Pharm Des. 2012;18(38):6232-40. doi: 10.2174/138161212803832344.
Though general anesthetics have now been used clinically for well over a century, both their mechanisms of action as well as the nature of any potentially neurotoxic side effects remain elusive. With roughly 234 million people undergoing surgery each year worldwide, it remains imperative that any potentially deleterious effects of anesthetics be investigated and addressed. The issue of anesthetic- induced neurotoxicity in certain subsets of patients has continued to garner attention over the past decade, as more pre-clinical and clinical studies released are suggesting that inhalational and intravenous anesthetics may both cause and mitigate existing significant neuropathology. Pre-clinically, both cell-culture and animal studies suggest that anesthetics may cause neuroapoptosis, caspase activation, neurodegeneration, β-amyloid protein (Aβ) accumulation and oligomerization, and ultimately, deficits in neurocognition. Interestingly, however, newer data suggest that certain volatile anesthetics, such as desflurane, may have a less harmful neurotoxic profile compared to others in the pre-clinical and clinical settings. Continued pre-clinical investigation may have significant impact on clinical practice in the near future. Clinically, recent studies have raised awareness that exposure to general anesthetics during childhood may be associated with an increased risk for subsequent deficits in learning, memory, and cognition. Furthermore, retrospective studies continue to allude to the potential effects of surgery and anesthesia on cognitive trajectory, and more specifically, post-operative cognitive dysfunction (POCD) in the elderly. Studies to date regarding both of these clinical topics, however, are fraught with confounders, and many are underpowered statistically. The aim of this review is to examine the current data (both pre-clinical and clinical) on anesthetic-induced neurotoxicity and argue that further data are needed to either support or refute the potential connection between anesthetics and neurotoxicity.
尽管全身麻醉在临床上已经应用了一个多世纪,但它们的作用机制以及任何潜在的神经毒性副作用的性质仍然难以捉摸。全球每年约有 2.34 亿人接受手术,因此必须调查和解决任何潜在的麻醉剂有害影响。在过去的十年中,麻醉诱导的神经毒性在某些特定患者群体中一直受到关注,因为越来越多的临床前和临床研究表明,吸入性和静脉内麻醉剂都可能导致和减轻现有的显著神经病理学。在临床前,细胞培养和动物研究都表明,麻醉剂可能导致神经细胞凋亡、半胱天冬酶激活、神经退行性变、β-淀粉样蛋白(Aβ)积累和寡聚化,最终导致神经认知功能障碍。然而,有趣的是,新的数据表明,某些挥发性麻醉剂,如地氟烷,与其他麻醉剂相比,在临床前和临床环境中可能具有较少的神经毒性。持续的临床前研究可能对不久的将来的临床实践产生重大影响。在临床上,最近的研究引起了人们的注意,即在儿童时期接触全身麻醉可能与随后学习、记忆和认知能力下降的风险增加有关。此外,回顾性研究继续暗示手术和麻醉对认知轨迹的潜在影响,更具体地说,对老年人术后认知功能障碍(POCD)的影响。然而,迄今为止关于这两个临床主题的研究都存在混杂因素,而且许多研究在统计学上的效力都不足。本综述的目的是检查关于麻醉诱导的神经毒性的当前数据(临床前和临床),并认为需要进一步的数据来支持或反驳麻醉剂和神经毒性之间的潜在联系。