Pulmonary blood flow does not redistribute in dogs with reposition from supine to left lateral position.
Pulmonary blood flow does not redistribute in dogs with reposition from supine to left lateral position.
复制标题
当狗从仰卧位调整到左侧卧位时，肺血流量不会重新分布。
DOI：
10.1097/00000542-199808000-00026
复制
发表时间：
1998
期刊：
影响因子：
8.8
通讯作者：
Glenny,RW
中科院分区：
文献类型：
--
作者：
Mure,M;Domino,KB;Robertson,T;Hlastala,MP;Glenny,RW
近年来的研究对经典的肺灌注重力模型提出了质疑。由于手术中通常采用侧卧位，因此作者使用高空间分辨率技术研究了左侧侧卧位时肺血流的再分布。方法采用15微米直径放射性标记微球静脉注射麻醉犬8只，随机取仰卧位和左侧侧卧位，观察肺血流分布。将无血的肺按全肺容量风干，并将每只动物切成1,498-2,396块（1.7 cm3）。用伽马计数器测量放射性，并根据片重对信号进行校正，并归一化为平均流量。结果侧卧位左肺血流量不增加，右肺血流量不减少。左肺仰卧位和左侧卧位灌注量分别为39.3+/-7.0%和39.2+/-8.8%（平均+/-SD）。对肺血流空间分布的详细评估显示，在侧卧位置缺乏血流重力梯度。仰卧位和左侧侧卧位的血流量分布无明显差异。结论从仰卧位到左侧卧位，各肺灌注量无明显变化。这些发现与基于重力模型的依赖性肺血流量增加和非依赖性肺血流量减少的预测相矛盾。由此可见，犬侧位血流分布以肺血管结构为主。
BackgroundRecent studies have questioned the classical gravitational model of pulmonary perfusion. Because the lateral position is commonly used during surgery, the authors studied the redistribution of pulmonary blood flow in the left lateral decubitus position using a high spatial resolution technique.MethodsDistributions of pulmonary blood flow were measured using intravenously injected 15-microm diameter radioactive-labeled microspheres in eight halothane-anesthetized dogs, which were studied in the supine and left lateral decubitus positions in random order. Lungs flushed free of blood were air-dried at total lung capacity and sectioned into 1,498-2,396 (1.7 cm3) pieces per animal. Radioactivity was measured by a gamma counter, and signals were corrected for piece weight and normalized to mean flow.ResultsBlood flow to the dependent left lung did not increase, and blood flow to the nondependent right lung did not decrease in the lateral position. The left lung received 39.3+/-7.0% and 39.2+/-8.8%(mean+/-SD) of perfusion in the supine and left lateral positions, respectively. Detailed assessment of the spatial distributions of pulmonary blood flow revealed the lack of a gravitational gradient of blood flow in the lateral position. The distributions of blood flow did not differ in the supine and left lateral decubitus positions.ConclusionsPerfusion to each lung did not change with movement from the supine to the left lateral position. These findings contradict the prediction of increased dependent lung and decreased nondependent lung blood flow based on the gravitational model. It was concluded that the distribution of blood flow in the lateral position in dogs is dominated by pulmonary vascular structure.