Effect of left pneumonectomy on lung mechanics in rabbits

Left pneumonectomy was performed in nine rabbits at 10 wk of age. Detailed pulmonary mechanics studies were performed at 14 wk of age in these rabbits and in nine littermate controls. Lung weight, total lung capacity, and static lung pressure-volume curves of the pneumonectomized rabbits were not different from those of the controls, but the forced vital capacity was smaller (P less than 0.05). Tantalum bronchograms of excised right lungs revealed no difference between controls and pneumonectomized rabbits in terms of bronchial diameter or pressure-area behavior of central or peripheral airways. Airways of pneumonectomized rabbits lengthened in accordance with the increase in lung volume. Over the midvolume range, the flow-limiting site moved from the trachea in controls to the right main bronchus in pneumonectomized rabbits. Maximal expiratory flow on air and on 80% He-20% O2 in the pneumonectomized rabbits average 70% of that in controls. This difference in flow was consistent with predictions based on the wave-speed theory of flow limitation.