The influence of lung volume on gas transfer in scoliosis

Abstract

Single-breath carbon monoxide transfer factor (DL co) and diffusion coefficient (K co) have been compared with vital capacity and total lung capacity in 119 subjects with scoliosis, 74 with idiopathic scoliosis, 32 with congenital osteogenic scoliosis and 13 with paralytic scoliosis. In each group mean values of DL co were below, and for K co above, predicted values. Furthermore, in each group, DL co was correlated with lung volume and K co inversely correlated with lung volume. The reduction in DL co is probably due to the reduction in the total alveolar surface area and the increased values for K co probably result from an increase in pulmonary capillary blood volume per unit alveolar volume at low lung volumes.