出血会导致麻醉大鼠肺部的肺泡间灌注分布不均。

Hemorrhage causes interalveolar perfusion maldistribution in the lungs of anesthetized rats.

作者信息

Conhaim Robert L, Watson Kal E, Heisey Dennis M, Leverson Glen E, Harms Bruce A

机构信息

Department of Surgery, Medical School, University of Wisconsin-Madison, BX 3236, 600 Highland Avenue, Madison, WI 53792-7375, USA.

出版信息

J Trauma. 2006 Jan;60(1):158-63. doi: 10.1097/01.ta.0000203110.03258.d0.

DOI:10.1097/01.ta.0000203110.03258.d0

PMID:16456450

Abstract

BACKGROUND

Lung injury often occurs following hemorrhage and we hypothesized that this might be due to the effects of hemorrhage on perfusion distribution among alveoli. To test this, we measured interalveolar perfusion distribution in anesthetized, spontaneously breathing rats subjected to blood losses of 0%, 10%, 20%, or 30% of calculated blood volume.

METHODS

We measured interalveolar perfusion distribution by analyzing trapping patterns of 4-mum diameter fluorescent latex particles infused into the pulmonary circulation. The particles (2 x 10) were infused 1 hour after each animal had been bled, and the lungs were then removed and air-dried. Using a confocal fluorescence microscope, we collected images of the particles in eight sections of each lung. Each image encompassed 3,360 x 3,360 x 100 microm (approximately 5,000 alveoli), and included 3-4,000 particles. Particle distributions in the images were measured using the method of dispersion index (DI) analysis. A DI value of zero corresponds to a statistically random distribution; the more DI exceeds zero, the more the distribution is clustered or inhomogenous.

RESULTS

The largest DI values for the four groups were: 0%, 0.69 +/- 0.41; 10%, 0.57 +/- 0.58; 20%, 0.72 +/- 0.34; 30%, 1.38 +/- 0.41. The 30% blood loss group had a max DI value approximately twofold greater than those of the other three (p < 0.0001).

CONCLUSIONS

Our results suggest that interalveolar perfusion distribution becomes markedly maldistributed at blood losses of 30%. This contributes to ventilation-perfusion mismatching, and may be a precipitating event for lung injury following hemorrhage.

摘要

背景

出血后常发生肺损伤，我们推测这可能是由于出血对肺泡间灌注分布的影响所致。为验证这一点，我们在麻醉、自主呼吸的大鼠中测量了肺泡间灌注分布，这些大鼠的失血量分别为计算血容量的0%、10%、20%或30%。

方法

我们通过分析注入肺循环的4微米直径荧光乳胶颗粒的捕获模式来测量肺泡间灌注分布。在每只动物出血1小时后注入颗粒（2×10），然后取出肺并风干。使用共聚焦荧光显微镜，我们在每个肺的八个切片中收集颗粒图像。每个图像涵盖3360×3360×100微米（约5000个肺泡），并包含3000 - 4000个颗粒。使用离散指数（DI）分析方法测量图像中的颗粒分布。DI值为零对应于统计上的随机分布；DI超过零越多，分布越聚集或不均匀。