Peritoneal Dialysis Therapy Prescription Adequacy Predicted with Standard and Fast PET

San Diego—The fast peritoneal equilibration test (PET) is used to determine peritoneal membrane transport status. However, there are few data quantifying the accuracy of using PET to predict parameters of peritoneal dialysis therapy. Researchers recently conducted a study designed to examine the ability of a new version of PD Adequest, a computer software program, to (1) compare mass transfer-area coefficients for urea, creatinine, and glucose during fast and standard PETs and (2) use those parameters to predict PD therapy prescription adequacy.

  1. Ken Leypoldt, PhD, and colleagues reported results of the study during a poster session at Kidney Week 2015. The poster was titled Predicting Peritoneal Dialysis Prescriptions with a Fast Peritoneal Equilibration Test Using PD Adequest.

Fluid and solute transport parameters were determined using data from 104 peritoneal dialysis patients (41 continuous ambulatory peritoneal dialysis, 63 automated peritoneal dialysis) who underwent a 4-hour standard PET and an overnight exchange with the same glucose concentration. Only data obtained at 4-hours during the standard PET and assuming a 200 mL residual volume in the prior exchange were used to compare calculated mass transfer-area coefficient values for standard PET with those for fast PET.

The calculated membrane parameters were used to predict net ultrafiltration, urea Kt/V, and creatinine clearance; those predictions of therapy adequacy were also compared with the mean of three actual measurements of net ultrafiltration, Kt/V, and creatinine clearance for each patient.

During standard PET, median urea, creatinine and glucose mass transfer-area coefficients were 20.9, 10.1, and 9.1 mL/min and 21.0, 10.1, and 9.0 mL/min during fast PET. The corresponding median absolute difference between mass transfer-area coefficients for urea, creatinine, and glucose were 0.6, 0.3, and 0.6 mL/min.

In comparisons of predictions using standard and fast PETs, 81% of net ultrafiltration were within 150 mL, 94% of Kt/V were within 0.1/wk, and 93% of creatinine clearance were within 2L/wk/1.73 m2. The percentages of predicted and actual measured values of net ultrafiltration within 300 mL were 44% for standard PET and 38% for fast PET; for Kt/V within 0.2/wk, the percentages were 63% for standard PET and 64% for fast PET; and for creatinine clearance within 8 L/wk/1.73 m2, the percentages were 77% for standard PET and 77% for fast PET. The differences were not statistically significant.

“These results suggest that the predictions of peritoneal dialysis therapy adequacy using PD Adequest are clinically equivalent when either fast of standard PET is employed,” the researchers said.

Source: Leypoldt JK, Agar BU, Sloand JA, Gellens M. Predicting peritoneal dialysis prescriptions with a fast peritoneal equilibration test using PD Adequest. Abstract of a poster presented during American Society of Nephrology Kidney Week 2015, November 5, 2015, San Diego, California.

This study was funded by Baxter Healthcare Corporation.