The impact of volume overload on technique failure in incident peritoneal dialysis patients

Background

Technique failure in peritoneal dialysis (PD) can be due to patient- and procedure-related factors. With this analysis, we investigated the association of volume overload at the start and during the early phase of PD and technique failure.

Methods

In this observational, international cohort study with longitudinal follow-up of incident PD patients, technique failure was defined as either transfer to haemodialysis or death, and transplantation was considered as a competing risk. We explored parameters at baseline or within the first 6 months and the association with technique failure between 6 and 18 months, using a competing risk model.

Results

Out of 1092 patients of the complete cohort, 719 met specific inclusion and exclusion criteria for this analysis. Being volume overloaded, either at baseline or Month 6, or at both time points, was associated with an increased risk of technique failure compared with the patient group that was euvolaemic at both time points. Undergoing treatment at a centre with a high proportion of PD patients was associated with a lower risk of technique failure.

Conclusions

Volume overload at start of PD and/or at 6 months was associated with a higher risk of technique failure in the subsequent year. The risk was modified by centre characteristics, which varied among regions.

Evolution Over Time of Volume Status and PD-Related Practice Patterns in an Incident Peritoneal Dialysis Cohort

BACKGROUND AND OBJECTIVES

Volume overload is frequent in prevalent patients on kidney replacement therapies and is associated with outcome. This study was devised to follow-up volume status of an incident population on peritoneal dialysis (PD) and to relate this to patient-relevant outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This prospective cohort study was implemented in 135 study centers from 28 countries. Incident participants on PD were enrolled just before the actual PD treatment was started. Volume status was measured using bioimpedance spectroscopy before start of PD and thereafter in 3-month intervals, together with clinical and laboratory parameters, and PD prescription. The association of volume overload with time to death was tested using a competing risk Cox model.

RESULTS

In this population of 1054 participants incident on PD, volume overload before start of PD amounted to 1.9±2.3 L, and decreased to 1.2±1.8 L during the first year. At all time points, men and participants with diabetes were at higher risk to be volume overloaded. Dropout from PD during 3 years of observation by transfer to hemodialysis or transplantation (23% and 22%) was more prevalent than death (13%). Relative volume overload >17.3% was independently associated with higher risk of death (adjusted hazard ratio, 1.59; 95% confidence interval, 1.08 to 2.33) compared with relative volume overload ≤17.3%. Different practice patterns were observed between regions with respect to proportion of patients on PD versus hemodialysis, selection of PD modality, and prescription of hypertonic solutions.

CONCLUSIONS

In this large cohort of incident participants on PD, with different treatment practices across centers and regions, we found substantial volume overload already at start of dialysis. Volume overload improved over time, and was associated with survival.

Repeated Bioimpedance Measurements Predict Prognosis of Peritoneal Dialysis Patients

BACKGROUND

Fluid overload is a major risk factor for mortality in patients undergoing peritoneal dialysis (PD). However, few studies have investigated the effect of chronic exposure to sustained fluid overload on long-term outcomes.

METHOD

A total of 284 prevalent PD patients were included in this prospective study. Repeated multifrequency body composition analysis was performed 12 months apart, and 1-year cumulative chronic fluid overload were used to predict all-cause mortality and the risk for transfer to hemodialysis (HD) during the ensuing 15.6 ± 9.1 months.

RESULTS

The prevalence of fluid overload was approximately 27%. Interestingly, a substantial number of hypervolemic patients at first test were persistently hypervolemic at their second test. With this, chronic fluid overload was observed in 18.3% (n = 52). Notably, most of chronic fluid overload patients had diabetes (86.5%), and it was accompanied by concomitant changes in peritoneal membrane characteristics, a higher progression rate to high transporter. The risk of transfer to HD increased 2.8 times in patients with chronic fluid overload than in those without. Also, it significantly increased the risk of mortality (p = 0.038). Surprisingly, subgroup analysis found that patients with euvolemic status at follow-up experienced no mortality despite being in a fluid overload state at baseline.

CONCLUSIONS

One-year chronic exposure to fluid overload is a strong independent risk factor for transfer to HD and death in prevalent PD patients. Although the fluid status of most PD patients is not easily changed over time, becoming euvolemic during the entire PD treatment period seems to be very important.

Peritoneal dialysis is not associated with myocardial stunning

BACKGROUND

Hemodynamic changes during hemodialysis can precipitate subclinical myocardial ischemia, which over time contributes to the development of cardiac failure and is associated with a poor prognosis. Peritoneal dialysis (PD) is also associated with acute changes in systemic hemodynamics and a similarly high incidence of cardiovascular disease; we therefore sought to examine whether the hemodynamic effects of a PD exchange would be sufficient to induce subclinical myocardial ischemia.

METHODS

10 patients on PD entered a prospective observational study to determine whether left ventricular (LV) regional wall motion abnormalities (RWMAs) developed following a dialysate exchange. Serial echocardiography with quantitative analysis was used to assess ejection fraction and regional systolic LV function (shortening fraction). Blood pressure (BP) and hemodynamic variables were measured using continuous pulse wave analysis.

RESULTS

We observed a very low frequency of RWMA development (5/100 regions). Only 1 patient had more than 1 RWMA and 6 patients were entirely unaffected. Overall mean shortening fraction increased when comparing pre and post values for both 2-chamber (from 3.06% ± 1.5% to 4.26% ± 1.3%, p = 0.001) and 4-chamber (from 3.00% ± 0.7% to 3.67% ± 0.9%, p = 0.021) analyses. Mean arterial pressure fell by a small degree during drainage of dialysate, with a larger rise in BP observed during instillation. These changes were driven by changes in peripheral resistance that fell during drainage and rose during instillation.

CONCLUSIONS

In contrast to hemodialysis, the acute effects of PD do not result in subclinical myocardial ischemia.