Investigation of the brain stem function using three different parameters analyzing the relation among respiration, heart rate variability, and direct arterial pressure.

第一年：我们开发了使用患者监护仪中的三个不同参数的分析方法；通过测量心电图(ECG)、直接动脉压(DAP)、呼吸道压力(RAP)和呼气末二氧化碳分压的R-R间期节段来测量心率变异性(HRV)。我们也开始为这一分析开发计算机程序。这种分析方法是基于快速傅立叶分析和脉冲响应分析。使用该计算机程序，我们在实验动物和临床条件下研究了RAP对HRV和HRV对DAP的影响。第二年：利用该计算机程序，我们继续在实验动物和临床条件下考察了RAP对HRV和HRV对DAP的影响。在脑损伤兔模型上，虽然RAP对DAP的HRV依赖于脑损伤的情况，但RAP对HRV没有任何影响。在重症监护的临床调查中，DAP的HRV随意识水平的升高而明显，而RAP对HRV的影响未观察到。我们必须改进RAP对HRV的分析方法，因为RAP和呼气末二氧化碳所代表的参数不足以进行调查。在下一步的研究中，胸阻抗可以代替这些参数。结论：尽管受试者接受了人工呼吸，但HRV严重依赖于呼吸状况。然而，在动物模型和人类研究中，RAP和HRV之间的关系并不明显。因此，需要进一步研究RAP与HRV、HRV与DAP之间的关系，以便临床应用。

1st year :We developed analytical procedures using 3 different parameters from patients monitor ; heart rate variability (HRV) by measuring R-R interval segments from electrocardiogram (ECG), direct arterial pressure (DAP), and respiratory airway pressure (RAP) and endtidal CO2. We also started to develop computer program for this analysis. This analytical procedures are based on the fast Fourier analysis and impulse response analysis. With this computer program, we investigated the effects between RAP on HRV and HRV on DAP in the experimental animals and in the clinical conditions.2nd year :With this computer program, we continued to investigate the effects between RAP on HRV and HRV on DAP in the experimental animals and in the clinical conditions. In the model of brain-damaged rabbits, it was turned out that artificial respiration did not produce any effect of RAP on HRV,although HRV on DAP was dependent on the condition of brain damage. In clinical investigation in the intensiv care, HRV on DAP was apparent with the level of consciousness, while any effect of RAP on HRV was not observed. We have to improve the analytical procedure using RAP on HRV because the parameters represented by RAP and endtidal CO2 were not sufficient enough for the investigation. Instead of these parameters, thoracic impedance would be appropriate in the next step investigation.Conclusion :It was concluded that HRV was seriously depending on the respiratory condition although the subjects were artificially ventilated. However, it was not apparent that relation between RAP and HRV in both animal models and human studies. It is therefore further needed to investigate the relation between RAP and HRV,and between HRV and DAP for clinical application.