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Updated: Aug 10, 2026

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism
Published on: February 14, 2022
Effect of positional change on ventilation-perfusion distribution in unilateral pleural effusion
1Division of Thoracic Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota.
Abstract:
The effect of pleural effusion on lung function and gas exchange has not been adequately defined. We used the multiple "inert" gas technique to study gas exchange and ventilation-perfusion relationships in both the left and the right lateral decubitus positions in a patient with a moderate unilateral (left) pleural effusion. With position change, only a small change in oxygenation (3 mm Hg) and no change in carbon dioxide tension occurred. The ventilation-perfusion relationships were also nearly identical for both body positions. We conclude that a pleural effusion of moderate size has little effect on overall gas exchange and ventilation-perfusion relationships and that complex mechanisms of the respiratory system compensate for the effusion.
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