Dynamic Relationship between Transvascular Fluid Shift and Cardiac Output.

为了研究不同病理生理状态下的跨血管液体移动，研制了一种连续测量循环血容量的装置。为了利用稀释原理测量血容量，用Cr51标记的红细胞作为示踪剂，用股动脉和股静脉进行体外分流。在体外分流管内放置伽玛射线计数器。放射性计数时间设定为每30秒一次，并将数据传输至微型计算机系统。该系统测量血容量的准确率超过98%，足以检测液体在血管壁中的移动。实验分为三种方案：1)二氧化碳应激，2)全脊髓阻滞。3)尼卡地平控制性低血压。在对照组和应激期，分别以1ml/kg/min的速度静脉滴注乳酸林格液10min，以测定跨血管滤过系数、血管顺应性和组织间隙顺应性，循环参数如心输出量、动脉压或静脉压与其他研究者报道的基本相同。然而，血容量和静脉压之间的关系发生了显著的变化。经血管滤过系数和组织间隙顺应性的计算值在每次实验中基本相同。尼卡地平组血管顺应性增加，二氧化碳和全脊髓阻滞组血管顺应性降低。血管形成延迟顺应性在所有应激阶段均降低。因此，我们得出结论，延迟顺应性是由自主神经系统调节的。

To investigate transvascular fluid shift under various pathophysiological states, a device for continuous measurement of circulating blood volume was developed. To use the dilution principle for measuring blood volume, Cr 51 tagged red blood cells were employed as a tracer and an extracorporeal shunt was made of the femoral artery and vein. Gamma ray counter was placed within the extracorporeal shunt. Counting time for the radioactivity was set at every 30 second and the data was transferred to microcomputer system. The accuracy of the blood volume determination was more than 98% with this system and it was sufficient to detect the movement of fluid shift through the vascular wall.Experiments with three different protocols were performed: 1) Carbon dioxide stress, 2) Total spinal block. 3) Nicardipine induced hypotension. To determine the transvascular filtration coefficient, the vascular compliance and the compliance of interstitial fluid space in whole body, lactate Ringer's solution was infused intravenously for 10 minutes at a rate of 1 ml/kg/min in the control phase and in those of stress phases.Circulatory parameters such as cardiac output, arterial pressure or venous pressure were almost same as reported by another investigators. However, significant changes in the relationship between blood volume and venous pressure were obtained. Calculated values of transvascular filtration coefficients and compliance of interstitial fluid space were almost same in each experiment. Compliance of vascularture were increased in Nicardipine group and decreased in carbon dioxide and total spinal block groups. Delayed compliance of vascularture were decreased in all stress stages. Hence, we conclude that the delayed compliance is regulated by autonomic nervous systems.