Respiratory evaluation of patients on continuous ambulatory peritoneal dialysis prior to renal transplantation

BACKGROUND AND AIM: Pulmonary function tests (PFTs) and cardiopulmonary exercise tests (CPETs) are important in predicting preoperative pulmonary complications and mortality rate in potentially renal transplant recipients. There is no adequate clinical research aimed at learning the effect of empty and full status of the peritoneal cavity on PFTs and CPET for estimating decide PFTs and CPET timing in preoperative evaluation. The aim of this study was to investigate whether PFT and CPET results are altered in patients on continuous ambulatory peritoneal dialysis (CAPD) according to the presence of dialysis solution in the abdomen. SUBJECTS AND METHODS: 22 subjects were included (12 male, 10 female, mean age 29.64 +/- 8.29 years, CAPD duration, 37.35 +/- 7.15 months). Data were collected from each patient when the peritoneal cavity was filled with solution (full status) and again when the cavity had been drained (empty status). Forced expiratory volume in 1 s (FEV1), ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), total lung capacity (TLC), and residual volume (RV) were calculated. Peak oxygen uptake (peak VO2) and exercise duration were determined by cardiopulmonary exercise testing. RESULTS: When the peritoneal cavity was empty, mean (+/- SD) values for the parameters tested were % predicted FEV1: 85 +/- 17%, %FEV1/FVC: 84 +/- 8%, % predicted TLC: 98 +/- 17%, % predicted RV: 108 +/- 25%, % predicted DLCO: 90 +/- 14%, peak VO2: 43 +/- 11 ml/kg/min, test duration: 6.8 +/- 1.6 min. When the peritoneal cavity was full, mean (+/- SD) values were % predicted FEV1: 86 +/- 17%, %FEV1/FVC: 83 +/- 7%, % predicted TLC: 91 +/- 14%, % predicted RV: 95 +/- 22%, % predicted DLCO: 87 +/- 16%, peak VO2: 42 +/- 8 ml/kg/min, test duration 6.5 +/- 1.7 min. % predicted FEV1, %FEV1/FVC, % predicted DLCO and peak VO2 were not statistically significant between the mean values at empty status versus those at full status (p < 0.05 for all). There were significant decreases between the mean values for % predicted TLC and % predicted RV at full status versus empty status (p < 0.002 for TLC, p < 0.001 for RV). No statistically significant correlation was found between PFTs and % change ratio of dialysate. CONCLUSION: FEV1, %FEV1/FVC, % predicted DLCO and CPET test results do not differ according to abdomen status in CAPD patients suggesting that the timing of PFT maneuver does not affect preoperative transplantation evaluation. Therefore, when evaluating the results of these tests prior to transplantation period, the presence of dialysis solution in the abdomen may be ignored.