Effect of renal transplantation on pulmonary function in patients with end-stage renal failure

Ten patients with end-stage renal failure on maintenance dialysis underwent serial lung function tests before and at monthly intervals after renal transplantation. Mean values of forced expiratory volume within 1 s, forced vital capacity, and total lung capacity were within the normal range before and up to 6, months after transplantation. The mean value of residual volume (RV) was above the normal range during all periods measured (157.8 +/- 21.5% predicted before transplantation and 121.2 +/- 17.0% predicted at 6 months after transplantation). No statistically significant changes in lung volumes were detected over a course of 6 months, but there was a trend for a reduction in RV after transplantation. The single-breath diffusion capacity for carbon monoxide (DLCO) was in the high-normal range before transplantation (115.7 +/- 9.5% predicted). It remained high at 1 month after transplantation (124.5 +/- 12.2% predicted), but it gradually came down to the normal range from the 2nd month onwards. At 6 months after transplantation the mean DLCO was 83.8 +/- 7.3% of predicted which was significantly (p < 0.0001) lower than the value before transplantation. We conclude that raised DLCO and RV values occurred in patients with end-stage renal failure on maintenance dialysis which were most likely the result of pulmonary vascular congestion, and these abnormalities tend to improve after renal transplantation.