Experimental Pulmonary Atelectasis. Changes in Chest Mechanics Following Block of One Lung

¹ From the Department of Surgery and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, New York

The effects of unilateral main stem bronchial occlusion upon the contralateral ventilation were studied in anesthetized dogs, with emphasis on the purely mechanical effects. Changes in the pressure-volume relationships of the open lung were found due to increased chest wall compliance since the blocked lung transmits force from that side of the chest wall and diaphragm through the mediastinum to act on the open lung. This chest wall compliance change is related to the quantity of blocked lung rather than to the quantity of gas it contains at the time of occlusion, and explains the tidal volume increase in the open lung. When one lung is blocked after either withdrawal or addition of gas to it, this lung's volume change is reflected partly by contralateral open lung volume change in the reverse direction and partly by chest volume change.