Consciousness and the 21st century operating room.
Consciousness and the 21st century operating room.
复制标题
意识与21世纪手术室。
DOI：
10.1097/aln.0b013e3182a7cad1
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发表时间：
2013
期刊：
影响因子：
8.8
通讯作者：
Mashour,GeorgeA
中科院分区：
文献类型：
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作者：
Mashour,GeorgeA
在与我们的麻醉科住院医师讨论术中监测时，我想描述以下涉及一位新患者和一位相当不寻常的心脏病专家的临床场景。在等待了几个月的预约后，琼斯夫人感到困惑的是，她的“心脏医生”只进行神经系统检查，并根据该检查要求进行压力测试。她惊讶地发现这项测试包括在跑步机上快跑，然后通过脑电图和大脑扫描进行诊断评估。为什么琼斯夫人感到困惑和不安？住院医师和您可以轻松识别问题：心脏病专家正在根据神经系统的数据对心血管系统进行推断，尽管心脏病学的目标器官是心脏。当然，好消息是现实生活中的心脏病学不是这样工作的……坏消息是现实生活中的麻醉学却是这样工作的。在世界各地的手术室中，麻醉医生正在根据心血管系统的数据来推断神经系统，尽管事实上，对于全身麻醉来说，麻醉的目标器官是大脑。在本期《麻醉学》中，Jordan 及其同事采用多种方法来评估人类异丙酚麻醉期间的大脑功能，并为意识神经生物学为我们的临床实践提供信息铺平了道路。 1 简而言之，Jordan 和他的共同研究人员发现，异丙酚引起的无意识与大脑前部结构到后部结构的定向连接减少有关（摘要见图 1）。他们通过使用符号传递熵技术（一种基于信息论的方法）对脑电图进行分析得出了这一结论。这具有神经生物学意义，因为来自前额叶皮层的这种“自上而下”或“反馈”处理被认为对人类意识特别重要。 2 大脑额叶至顶叶区域的反馈连接受损先前已被认为与人类使用丙泊酚、七氟醚和氯胺酮诱导无意识有关（相关研究综述见表 1）3-9 以及大鼠的异氟醚。 10 目前的研究是独一无二的，因为它在两个方向上扩展了调查。首先，除了使用脑电图之外，乔丹和同事还使用功能磁共振成像来评估潜在的大脑事件。其次，他们对高密度脑电图记录进行了单独分析，并确定了额叶区域的选择性变化，这些变化可能适合术中监测。因此，它们帮助弥合了翻译差距，并增进了我们对麻醉机制和麻醉监测的理解。现在，根据他们的神经影像学发现，我们知道，在先前的研究中观察到的自上而下（反馈）处理的丧失与前部和前部之间的功能脱节有关。
During discussions of intraoperative monitoring with our anesthesiology residents, I like to describe the following clinical scenario involving a new patient and a rather unusual cardiologist. After waiting months for an appointment, Mrs. Jones is befuddled that her “heart doctor” performs only a neurologic examination and, on the basis of that examination, has ordered a stress test. She is flabbergasted to discover that this test consists of a brisk run on the treadmill followed by diagnostic evaluations with electroencephalography and brain scanning. Why is Mrs. Jones confused and upset? The residents—and you—can easily identify the problem: the cardiologist is making inferences about the cardiovascular system based on data from the nervous system, despite the fact that the target organ of cardiology is the heart. The good news, of course, is that real-life cardiology doesn’t work this way… the bad news is that real-life anesthesiology does. In operating rooms around the world, anesthesia providers are making inferences about the nervous system based on data from the cardiovascular system, despite the fact that—for general anesthetics—the target organ of anesthesiology is the brain. In this issue of Anesthesiology, Jordan and colleagues take multiple approaches to assessing brain function during propofol anesthesia in humans and pave the way for the neurobiology of consciousness to inform our clinical practice. 1In brief, Jordan and his coinvestigators found that propofol-induced unconsciousness is associated with a reduction of directed connectivity from anterior to posterior brain structures (see fig. 1 for summary). They derived this conclusion from the analysis of electroencephalography using the technique of symbolic transfer entropy, a method based in information theory. This has neurobiological significance, because such “top-down” or “feedback” processing from the prefrontal cortex is thought to be particularly important for human consciousness. 2 Impairment of feedback connectivity from frontal to parietal areas of the brain has previously been associated with induction of unconsciousness using propofol, sevoflurane and ketamine in humans (see table 1 for review of relevant studies) 3–9 as well as isoflurane in rats. 10 The current study is unique because it extended investigation in two directions. First, in addition to using electroencephalography, Jordan and colleagues used functional magnetic resonance imaging to assess underlying brain events. Second, they conducted a separate analysis of their high-density electroencephalography recordings and identified selective changes in the frontal region that could be amenable to intraoperative monitoring. As such, they have helped bridge a translational gap and advanced our understanding of anesthetic mechanisms as well as anesthetic monitoring. We now know based on their neuroimaging findings that the loss of top-down (feedback) processing observed in prior studies is associated with functional disconnections between anterior and