Transient paradoxical dissociation of alveolar volume indices after single-lung transplantation in a patient with severe emphysema: A case report.

Measurement of the alveolar volume (VA) yields two distinct values, VA-MB and VA-SB; theoretically, the VA-MB should exceed the VA-SB. This report describes a case in which the VA-MB was less than the VA-SB following unilateral lung transplantation. After the exclusion of mechanical errors and suboptimal procedural techniques, further analysis revealed that, following unilateral lung transplantation, substantial disparities in respiratory function between the left and right lungs, as seen in severe emphysema, may trigger a physiological mechanism that reverses VA-SB and VA-MB. As a result, the pulmonary diffusing capacity of each lung may not be accurately reflected by these measurements.