INTRODUCTION In peritoneal dialysis (PD) patients, volume overload is related to cardiac dysfunction and mortality, while intravascular volume depletion is associated with a rapid decline in the residual renal function (RRF). This study sought to determine the clinical usefulness of bioimpedance spectroscopy (BIS)-guided fluid management for preserving RRF and cardiac function in PD patients.

SUBJECTS AND METHODS This is a multicenter, prospective, open-label study that was conducted over a 1-year period (NCT01887262). Non-anuric (urine volume > 500 mL/day) subjects on PD were enrolled. Subjects in the control group received fluid management based on the clinical information alone. Those in the BIS group received BIS-guided fluid management along with clinical information.

RESULTS The subjects (N = 137, mean age 51.3 ± 12.8 years, 54% male) were randomly assigned to the BIS group (n = 67) or to the control group (n = 70). There were no significant differences between the 2 groups with regard to age, sex ratio, cause of kidney failure, duration of PD, baseline comorbidity, RRF, PD method, or peritoneal transport type. At baseline, the 2 groups were not different in terms of RRF (glomerular filtration rate [GFR], 5.1 ± 2.9 vs 5.5 ± 3.7 mL/min/1.73 m²). After follow-up, changes in the GFR between the 2 groups were not different (-1.5 ± 2.4 vs -1.3 ± 2.6 mL/min/1.73 m², p = 0.593). Over the 1-year study period, both groups maintained stability of various fluid status parameters. Between the 2 groups, there were no differences in the net change of various fluid status parameters such as overhydration (OH) and extracellular water/total body water (ECW/TBW). A net change in ECW over 1 year was slightly but significantly higher in the control group (net increase, 0.57 ± 1.27 vs 0.05 ± 1.63 L, p = 0.047). However, this difference was not translated into an improvement in RRF in the BIS group. There were no differences in echocardiographic parameters or arterial stiffness at the end of follow-up.

CONCLUSION Routine BIS-guided fluid management in non-anuric PD patients did not provide additional benefit in volume control, RRF preservation, or cardiovascular (CV) parameters. However, our study cannot be generalized to the whole PD population. Further research is warranted in order to investigate the subpopulation of PD patients who may benefit from routine BIS-guided fluid management.