Correlation between peritoneal equilibration test and dialysis adequacy and transport test, for peritoneal transport type characterization

Objective:The aim of this study was to analyze the correlation between the peritoneal equilibration test (PET) and the dialysis adequacy and transport test (DATT) for peritoneal transport type characterization, and the degree of patients' acceptance for each test. Design: Cross-sectional, observational multicenter study. Setting: Five referral (tertiary) dialysis centers of institutional practic e. Patients:The study included 107 adult continuous ambulatory peritoneal dial ysis (CAPD) patients with a prescription of four exchanges of 2 L per day, irrespective of age, gender, cause of end-stage renal disease, time on dial ysis, nutritional status, or residual renal function. Patients on immunosup pressive therapy and those with cancer, hepatitis B, or HIV, and those havi ng a peritonitis episode within the previous 30 days, or three or more epis odes during the previous 12 months, were excluded. Main Measures: Peritoneal transport type as classified by creatinine and ur ea dialysis-to-plasma (DIP) ratios by PET and DATT. Results: Correlation coefficients between DIP ratios for creatinine and ure a, obtained for the PET and the DATT, were 0.73 for D/P creatinine and 0.36 for D/P urea. Patients were classified into high, high-average, low-averag e, and low transport categories according to the mean and standard deviatio n of DIP creatinine values obtained from the PET at 4 hours. These values s howed excellent concordance with those generated from the DATT data (kappa = 0.32, 95% confidence interval 0.67 - 0.93). Nineteen percent of patients showed discordance in their category when classified according to the PET v ersus the DATT. Patients' acceptance was better for the DATT than for the P ET, as evaluated with a questionnaire. Conclusion:The DATT is an easy, inexpensive, and reliable test to assess pe ritoneal transport type, and it also provides information about peritoneal clearance of solutes and ultrafiltration. The DATT has better patient accep tance than the PET. Since the DATT has only been validated for patients on a fixed CAPD daily schedule of 4 x 2 L, the results should be confined only to patients receiving such a prescription.