LAUSR

V/ _ Q matching caused by VT increases, allowing VD/VT to remain unchanged in the upper lung field, which already had sufficient ventilated regions (high _ V/ _ Q). Therefore, BPA created more low_ V/ _ Q units and decreased diffusing capacity of the lung for carbon monoxide (DLCO) in the lower lung field, which resonates with our hypothesis. Furthermore, Kapitan et al reported that DLCO remained unchanged even after successful pulmonary endarterectomy and BPA. Throughout the duration of BPA, with treatment to both upper and lower lung fields, DLCO was considered to be counterbalanced; further, its reading remained unchanged after BPA.