24-Hour Dialysate Collection for Determination of Peritoneal Membrane Transport Characteristics: Longitudinal Follow-Up Data for the Dialysis Adequacy and Transport Test (Datt)

Abstract

Objective

To determine the ability of the dialysis adequacy and transport test (DATT) to monitor changes in peritoneal transport characteristics over time.

Setting

University-based peritoneal dialysis program.

Patients

One hundred patients on continuous ambulatory peritoneal dialysis who underwent 226 simultaneous DATTs and peritoneal equilibration tests (PET).

Methods

Retrospective analysis of DA TT and PET data.

Results

The mean 24-hour dialysate-to-plasma creatinine (cr) concentration ratio (DIP cr) from the DATT was 0.70±0.10, and the mean four-hour DIP crfrorn the PET was 0.68 ± 0.10. The correlation coefficient between the fourhour and 24-hour DIP cr was 0.81, and the standard error of estimate was 0.065. The mean (±SD) difference between the four-hour and 24-hour DIP cr was 0.023 ± 0.061. Fifty eight patients had two or more sequential DA TTs and PETs. For these 94sets of sequential DATTs and PETs, the mean (±SD) difference between the change in the four-hour DIP cr and the change in the 24-hour DIP cr was 0.020 ± 0.024, and the standard error of estimate was 0.064. In 17 patients a change in dwell volume from 2.0 L to 2.5 L occurred between the first and second measures of peritoneal membrane transport characteristics. The mean (±SD) difference between the change in the four-hour DIP cr and the change in the 24-hour DIP cr was 0.036 ± 0.055, and the standard error of estimate was 0.087.

Conclusion

The DATT can be used to monitor for changes in peritoneal transport over time. It should not be used in patients receiving cycler therapy or in patients whose dwell times and dextrose concentrations vary markedly from day to day.