仰卧和俯卧位心脏对肺压迫作用的CT探讨

目的：探讨俯卧位改善肺通气功能的机理。方法：对7例健康成人行仰卧位、俯卧位高分辨率CT扫描，选取气管隆突下、左心房、左心室上、左心室下4个层面，分别测量位于心脏下方肺组织的体积，用配对t检验进行统计分析。结果：仰卧位时左肺的8.2%-44.7%，右肺的5.5%-10.8%位于心脏下区；俯卧位时左肺的0.1%-1.9%，右肺的0.8%-4.2%位于心脏下区。俯卧位时心脏下受压肺组织明显减少（P＜0.01）。结论：俯卧位时可明显改善人体的肺换气功能。

The difference of compression of lungs by the heart in the supine and prone position:a CT study

Objective:To study the potential mechanism of the prone position improving gas exchange of the lungs.Methods:Seven healthy adults were performed high resolution CT scanning in both the supine and the prone position.The four axial tomographic sections between the carina and the diaphragm were selected to measure the relative volume of lung located directly under the heart in the supine and prone position,respectively.Results:When supine,the total volume of left and right lung located under the heart was 8.2% to 44.7% and 5.5% to 10.8%,respectively;When prone,the total volume of the left and right lung located under the heart was 0.1% to 1.9% and 0.8% to 4.2%,respectively.The relative volume of lung is significantly less in prone position than in supine position ( P <0.01).Conclusion:The prone position improves obviously gas exchange of the lung in human.