Effect of preoperative hyperinflation on static lung volumes after lung transplantation.

It is still not known whether persistent increases in functional residual capacity (FRC) and residual volume (RV) after lung transplantation are due to preexisting hyperinflation. Therefore, the aim of this study was to determine the effects of chronic lung hyperinflation on static lung volumes after heart/lung (HLT) and bilateral lung transplantation (BLT). Static lung volumes were measured in 33 patients before and at 6 month intervals for up to 3 yrs after HLT (n=25) or BLT (n=8). The preoperative diagnosis was cystic fibrosis in 25 patients and other chronic hyperinflated lung diseases in eight patients. After surgery, total lung capacity returned to predicted normal values but FRC and RV remained greater than expected for either the recipient or the donor. At 1 yr after surgery, mean+/-SD FRC and RV were 130+/-18% and 151+/-34% of the predicted values for the recipient (p<0.001), and these figures did not change significantly over time. Similar abnormalities were found in patients with and without cystic fibrosis. After transplantation for lung diseases producing chronic hyperinflation, there is a persistent increase in functional residual capacity and residual volume. This alteration is present in patients operated on for diseases developed in both childhood and adulthood and is not recovered over time. It may be due to irreversible changes in the structure of the ribcage.