Spatial pattern of pulmonary blood flow distribution is stable ever days
Spatial pattern of pulmonary blood flow distribution is stable ever days
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DOI：
10.1152/jappl.1997.82.3.902
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发表时间：
1997-03-01
影响因子：
3.3
通讯作者：
Robertson, KT
中科院分区：
文献类型：
--
作者：
Glenny, RW;McKinney, S;Robertson, KT
尽管局部肺灌注在空间上的不均匀分布，但局部灌注在短时间内（20-100分钟）保持稳定。本研究的目的是确定肺灌注的空间分布是否在较长的时间段（1-5天）内保持稳定。在5只清醒站立的狗中，每天测量局部血流量，持续5天。每天将不同颜色的荧光微球注射到肢体静脉中超过30 s。最后一次注射微球后，处死犬，冲洗肺部，清除血液，切除，干燥至总肺容量，并切成类似2 cm（3）的碎片（每只犬n = 1，296 - 1，487）。通过提取荧光染料并确定每种颜色的浓度，确定每天每件的相对血流量。我们确定血流在空间上是不均匀的，变异系数为29.5 ± 2%。每片的血流量与所有天数相同片的血流量高度相关（r = 0.930 +/- 0.006）。在5天内，通过变异系数测量的局部灌注的时间异质性为6.9 +/- 0.7%，并且是非随机的。空间和时间变化的幅度显着小于先前在一项研究中报告的麻醉和机械通气的狗使用。我们的结论是，肺血流的空间分布保持稳定的日子，我们推测，在正常清醒的狗区域灌注主要是由一个固定的结构，如肺血管树的几何形状，而不是由当地的血管活性调节剂。麻醉和/或机械通气可能会增加局部灌注的时间变异性。
Despite the heterogeneous distribution of regional pulmonary perfusion over space, local perfusion remains stable over short time periods (20-100 min). The purpose of this study was to determine whether the spatial distribution of pulmonary perfusion remains stable over longer time periods (1-5 days). Regional blood flow was measured each day for 5 days in five awake standing dogs. Fluorescent microspheres of different colors were injected into a limb vein over 30 s on each day. After the last microsphere injection, the dogs were killed, and lungs were flushed free of blood, excised, dried at total lung capacity, and diced into similar to 2-cm(3) pieces (n = 1,296-1,487 per dog). Relative blood flow to each piece on each day was determined by extracting the fluorescent dyes and determining the concentrations of each color. We established that blood flow is spatially heterogeneous with a coefficient of variation of 29.5 +/- 2%. Blood flow to each piece is highly correlated with flow to the same piece on all days (r = 0.930 +/- 0.006). The temporal heterogeneity of regional perfusion as measured by the coefficient of variation is 6.9 +/- 0.7% over the 5 days and is nonrandom. The magnitude of spatial and temporal variation is significantly less than previously reported in a study in which anesthetized and mechanically ventilated dogs were used. We conclude that spatial distribution of pulmonary blood flow remains stable over days and we speculate that in the normal awake dog regional perfusion is determined primarily by a fixed structure such as the geometry of the pulmonary vascular tree rather than by local vasoactive regulators. Anesthesia and/or mechanical ventilation may increase the temporal variability in regional perfusion.