Comparison of a 2.5% and a 4.25% dextrose peritoneal equilibration test

Abstract

◆ 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/D0) 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/D0 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.