Comparison of a 2.5% and a 4.25% Dextrose Peritoneal Equilibration Test

Background Ultrafiltration (UF) failure develops over time in some patients on peritoneal dialysis. The workup of UF failure can be difficult and the 4.25% peritoneal equilibration test (PET) has been suggested to be more useful than the 2.5% PET for the workup of UF failure. It is unknown how a 4.25% PET compares to a 2.5% PET in individual patients. Objectives To assess the differences in drain volumes and sodium sieving using a 4.25% PET compared to a 2.5% PET, and to determine whether peritoneal transport rates, in terms of dialysate-to-plasma (D/P) ratios, are comparable between the two. Design Pilot study with each patient serving as his or her own control. Setting Outpatient dialysis facility of Wake Forest University Baptist Medical Center. Patients 47 patients, all of whom had a 2.5% PET and a 4.25% PET performed within 1 week of each other. Outcome Measures Dialysate-to-plasma ratios of urea and creatinine, dialysate total protein, and dialysate glucose compared to time zero (D/D 0 ) at 0, 2, and 4 hours. Four-hour drain volumes and sodium sieving at 2 hours were also measured. Results There was reproducibility between the 2.5% and 4.25% PET for D/P ratios of urea and creatinine and for dialysate total protein. There were expected differences in drain volume, sodium sieving, and D/D 0 glucose between the two methods. Conclusions The use of a 4.25% PET may be more useful for the workup of UF failure because of the accentuation of drain volume and sodium sieving, while remaining useful for prescription management.