Background: Bioimpedance spectroscopy (BIS) is used to assess volume status in peritoneal dialysis (PD) patients. However, it is proposed that it may be troubling in patients with abnormal fluid distribution and body geometry. It is not clear whether having an empty abdomen or not interferes with the BIS results and its relation with echocardiographic findings in PD patients.
Methods: Twenty-five prevalent PD patients were enrolled. Echocardiography and body composition analysis using BIS technique (50 frequencies, the Body Composition Monitor, BCM) were performed. Overhydration (OH), extracellular water (ECW) in liters and OH/ECW ratio were used as volume status indices. Differences in volume and echocardiographic findings, in patients with empty and with full abdomen, and their correlations with echocardiographic parameters were investigated.
Results: Mean age and PD duration were 61 ± 2.5 years and 42 ± 33 months, respectively. Sixty-four percent were male and 24% were diabetic. Mean left ventricular mass index (LVMi) was 131 ± 43 g/m (,) (2) mean left atrium diameter (LA) was 4.1 ± 0.1 cm, mean left ventricular ejection fraction (EF) was 64 ± 10%. Mean OH in patients with full abdomen were 1.67 ± 1.51 L and 1.68 ± 1.48 L, depending on the inclusion or exclusion of the dialysate volume, respectively. In patients with an empty abdomen, mean OHs were 2.12 ± 1.76 L and 1.91 ± 1.56 L, depending on the inclusion or exclusion of the dialysate volume. BIS measurements with an empty, but not with a full abdomen, was related to the echocardiographic parameters.
Conclusion: BIS is a reliable method to evaluate volume status in PD patients. BIS performed after peritoneal equilibration test with an empty abdomen, better reflects overhydration and is related to echocardiographic parameters.