Liver Tissue Blood Flow Measurement Using the Microbubble Method

首先在家兔模型上用彩色微球法进行器官血流量测量，建立了微泡法测量肝组织血流量的方法。虽然机械通气可以减少呼吸肌的工作负荷，但通气设置对呼吸肌和主要器官血流量的影响研究很少。采用不同颜色微球法，对家兔模型在不同机械通气条件下呼吸肌和主要器官的局部血流量进行了测量。新西兰白色家兔10只，氯胺酮和异丙酚持续静脉麻醉后气管切开。通过左颈动脉将19G导管插入左心室以注射有色微球。对右股动脉进行插管以采集血样。应用肌松剂，观察压力支持通气（PSV）0、6、12cmH_2O和压力控制通气（PCV）6、12cmH_2O时膈肌、肾脏和肝脏局部血流的变化。PSV 6、PCV 6、12cmH_2O时膈肌血流量明显小于PSV 0cmH_2O时（p<0.05）。其他器官包括肾脏和肝脏的血流量在实验设置中没有显着变化。我们推测，膈肌血流量的差异是由于呼吸机和动物之间的吸气阻力。通过本研究，我们可以建立一种测量器官血流量的方法。目前我们正在尝试建立一种以彩色微球法测得的数值作为对照值的微泡法来测量局部肝组织血流量。

At first organ blood flow measurements were conducted in a rabbit model using the colored-microsphere method to establish the liver tissue blood flow measurement by the micobubble method. Although mechanical ventilation reduces the respiratory muscle workload, the effects of ventilatory settings on blood flows of respiratory muscle and major organs have been little studied. Using the different-colored microspheres method, we measured the regional blood flow of respiratory muscle and major organs at different mechanical ventilatory settings in a rabbit model. Ten New Zealand white rabbits were anesthetized by continuous infusion of ketamine and propofol and then tracheostomized. A 19G catheter was inserted into the left ventricle via the left carotid artery to inject colored microspheres. The right femoral artery was cannulated for blood sampling. The regional blood flows in diaphragm (Diaphcost, crur), kidney and liver were studied during pressure support ventilation (PSV) of 0, 6, 12 cmH_2O and then pressure controlled ventilation (PCV) of 6 and 12 cmH_2O after the administration of muscle relaxant. Blood flows in diaphragm during PSV6, PCV 6, 12cmH_2O were significantly smaller than that during PSV0cmH_2O (p<0.05). Blood flows in other organs including kidney and liver did not change significantly among ventilatory settings. We speculate that the difference of blood flow in diaphragm was derived from the inspiratory asynchrony between the ventilator and the animal. With this study we could establish a method to measure organ blood flow. Now we are trying to establish the microbubble method to measure regional liver tissue blood flow using the values measured by the coloredmicrosphere method as control values.