Peritoneal Equilibration Test and Patient Outcomes

Abstract

Background and objectives Although a peritoneal equilibration test yields data on three parameters (4-hour dialysate/plasma creatinine, 4-to 0-hour dialysate glucose, and 4-hour ultrafiltration volume), all studies have focused on the prognostic value of dialysate/plasma creatinine for patients undergoing peritoneal dialysis. Because dialysate 4-to 0-hour glucose and ultrafiltration volume may be superior in predicting daily ultrafiltration, the likely mechanism for the association of peritoneal equilibration test results with outcomes, we hypothesized that they are superior to dialysate/plasma creatinine for risk prediction.Design, setting, participants, & measurements We examined unadjusted and adjusted associations of three peritoneal equilibration test parameters with all-cause mortality, technique failure, and hospitalization rate in 10,142 patients on peritoneal dialysis treated between January 1, 2007 and December 31, 2011 in 764 dialysis facilities operated by a single large dialysis organization in the United States, with a median follow-up period of 15.8 months; 87% were treated with automated peritoneal dialysis.Results Demographic and clinical parameters explained only 8% of the variability in dialysate/plasma creatinine. There was a linear association between dialysate/plasma creatinine and mortality (adjusted hazards ratio per 0.1 unit higher, 1.07; 95% confidence interval, 1.02 to 1.13) and hospitalization rate (adjusted incidence rate ratio per 0.1 unit higher, 1.05; 95% confidence interval, 1.03 to 1.06). Dialysate/plasma creatinine and dialysate glucose were highly correlated (r=20.84) and yielded similar risk prediction. Ultrafiltration volume was inversely related with hospitalization rate but not with all-cause mortality. None of the parameters were associated with technique failure. Adding 4-to 0-hour dialysate glucose, ultrafiltration volume, or both did not result in any improvement in risk prediction with dialysate/plasma creatinine alone.Conclusions This analysis from a large contemporary cohort treated primarily with automated peritoneal dialysis validates dialysate/plasma creatinine as a robust predictor of outcomes in patients treated with peritoneal dialysis.

Thyroid Functional Disease and Mortality in a National Peritoneal Dialysis Cohort

“…All laboratory testing was conducted using automated and standardized methods. We also considered peritoneal equilibration test (PET) data, which included 1) the ratio of the dialysate to plasma creatinine (D/P Cr ratio) at the end of a 4-hour dwell (dichotomized as Ͻ0.65 vs Ն0.65, respectively), as well as 2) the ultrafiltration volume at the end of the 4-hour dwell, defined as "4-hour PET ultrafiltration volume ϭ 4-hour drain volume Ϫ 4-hour infusion volume" (23).…”

Predicting Risk in Peritoneal Dialysis

“…Hence, the diffusion rate of glucose out of the peritoneal cavity, which will determine the osmotic pressure gradient over the time of the dwell and the volume of fluid ultrafiltered over the 4-hour PET, may be more relevant if volume status is a stronger predictor of survival than small solute kinetics. Nonetheless, the study showed that peritoneal D/P creatinine was consistently associated with mortality and hospitalization rates, despite adjustment for comorbidities and the use of APD (14). Ultrafiltration volume from the PET was not associated with mortality but did show a strong association with hospitalization rates.…”

“…Interestingly and reminiscent of the studies discussed above, those with higher D/P creatinine who were treated with continuous ambulatory PD had a greater risk of death and hospitalization than patients treated at any time with APD (14).…”

“…Reanalysis of the CANUSA Study showed that, for every 250 ml daily urine volume, there was a 36% reduction in mortality (11). This important factor was not analyzed in this study and likely had a very strong influence in determining volume status (14).…”

“…In this issue of the Clinical Journal of the American Society of Nephrology, Mehrotra et al (14) examined a large cohort of patients who had baseline PET. The three parameters that were compared for their predictive values were the D/P creatinine, D4/D0 glucose, and the volume ultrafiltered during the 4-hour dwell with 2.5% dialysate.…”