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

我们开发了一种测量肌肉交感神经活动的系统，可以量化它们的活动水平。该系统利用电磁屏蔽和隔离差分前置放大器，在手术室或重症监护室中识别神经突发电位和环境噪声。通过该定量测量系统，我们发现：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。星状神经节阻滞使心率和全身血压升高，其原因估计是主动脉弓上压力感受器的迷走神经活动传入通量被阻滞。我们发现，由于传出肌交感神经活动（MSNA）受到压力感受器反应的影响，左侧星状神经节阻滞增加了胫骨神经的传出肌MSNA。在5、10和15 mmHg时，持续正压呼吸（CPPB）水平的增加会导致MSNA水平的增加，然而，在持续负压呼吸（CNPB）期间，MSNA实际上是恒定的。在CPPB期间，平均血压下降，心率升高，而在CPPB期间，这两个因素都没有显著变化。CPPB期间CVP升高，CNPB期间CVP降低。这些结果表明，CPPB和CNPB对MSNA没有相反的影响。

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.