Effects of Changing Body Position upon Improved Ventilation-Perfusion Relationships

Abstract

Ventilation-perfusion relationships were studied in patients in the lateral and supine positions by monitoring blood gas tensions of peripheral arterial and pulmonary vein blood samples. West observed in erect subjects that the apex of the lung, while oxygenating less blood than the base, effected a higher P o o2 . This study shows that in patients not in the erect position the nondependent lung, lobe or portion of lung achieved higher P o o2 values than the dependent. The supine position was found to be associated with low peripheral arterial oxygen tensions. The simple maneuver of having the patient turn to a lateral position was found to increase oxygen tensions to satisfactory levels.