Development of Sympathetic Nerve Activity Quantitative Analysis System in Anesthesia and Intensive Care Area

我们研制了一套测量肌肉交感神经活动（MSNA）的系统，可以量化它们的活动水平。该系统使用电磁屏蔽和隔离差分前置放大器，用于区分神经中的电爆发电位与手术室或重症监护室中的环境噪声。利用该定量测量系统，我们发现了临床发现：1）星状神经节阻滞对胫神经肌肉交感神经活动的影响。2)正负压呼吸对肌肉交感神经活动的影响。星状神经节阻滞可使心率和体循环血压增加，其原因可能是阻断了主动脉弓上压力感受器的迷走神经活动传入，而左星状神经节阻滞可使胫神经的传出MSNA增加，这是因为传出肌交感神经活动（MSNA）受压力感受器反应的影响。在5、10和15 mmHg下持续正压呼吸（CPPB）水平的增加导致MSNA水平的增加，然而，在持续负压呼吸（CNPB）期间，MSNA几乎是恒定的。CPPB时平均血压降低，心率增加，CPPB时两项指标均无明显变化。CPPB时CVP升高，CNPB时CVP降低。

We have developed the system which could measure muscle sympathetic nerve activity (MSNA) and could quantify the activity level of them. The system used the electro-magnetic shielding and isolated differential preamplifiers for discriminating electrical burst potential in the nerve from the environmental noise in surgical rooms or in the intensive care rooms. By using this quantitative measurement system, we have found the clinical findings : 1) Effects of stellate ganglion block on tibial nerve muscle sympathetic activity. 2) Effects of positive and negative pressure breathing on muscle sympathetic nerve activity. Stellate ganglion block increases heart rate and systemic blood pressure, and the reason is estimated as the block of afferent flux of vagal nerve activity from the baroreceptor on the aortic arch. We have found that the left stellate ganglion block increased efferent MSNA on tibial nerve because of the efferent muscle sympathetic nerve activity (MSNA) is affected by the baroreceptor response. Increasing levels of continuous positive pressure breathing (CPPB) at 5,10, and 15 mmHg produced increasing levels of MSNA,however, during continuos negative pressure breathing (CNPB), MSNA was virtually constant. Mean blood pressure decreased and heart rate increased during CNPB,while neither factor changed significantly during CPPB.CVP increased during CPPB and decreased during CNPB.These results suggest that CPPB and CNPB do not have the inverse effects on MSNA.