Kidney Week

Abstract: FR-PO496

Assessment of Fluid Transport Between Extra- and Intraperitoneal Spaces During Peritoneal Dialysis Using Segmental Bioimpedance

Session Information

• Peritoneal Dialysis: Current Topics
  November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 702 Dialysis: Home Dialysis and Peritoneal Dialysis

Authors

• Zhu, Fansan, Renal Research Institute, New York, New York, United States

Fansan Zhu,

• Rosales, Laura, Renal Research Institute, New York, New York, United States

Laura Rosales,

• Tisdale, Lela, Renal Research Institute, New York, New York, United States

Lela Tisdale,

• Villarama, Maricar, Mount Sinai Hospital Mount Sinai Heart, New York, New York, United States

Maricar Villarama,

• Kotanko, Peter, Renal Research Institute, New York, New York, United States

Peter Kotanko,

Background

In peritoneal dialysis (PD), ultrafiltration (UF) failure is generally attributed to excessive absorption of dialysate from the peritoneal cavity. Currently, we are lacking methods to measure the peritoneal fluid absorption rate. Our goal was to evaluate whether fluid absorption and UF can be assessed by monitoring intraperitoneal fluid volume using segmental bioimpedance analysis (SBIA).

Methods

Twenty PD patients were studied during either a peritoneal equilibration test (PET; n=7) or automated PD (APD; n=13). Eight electrodes were placed on the lower abdomen (Fig.1) and connected to a bioimpedance device (Hydra 4200). The abdominal extracellular volume (V_ABD) was measured comprising the tissues surrounding the peritoneal cavity (V_EPF) plus the intraperitoneal (V_IPF) fluid (Fig.2). Baseline was defined as the V_ABD at the state prior to dialysate fill (V_IPF = 0). ΔV_EPF was calculated after dialysate drainage (V_IPF = 0) minus the baseline. ΔV_Dwell was defined as V_ABD at the end, minus V_ABD at the start of the dialysate dwell. The change in ΔV_Dwell was due to UF or fluid absorption. The clinically measured UF volume (UVF_Clin) was calculated as the weight of the drained dialysate fluid minus the dialysate fill (2 L; approximated as 2 kg).

Results

UFV_Clin and UFV_SBIA were highly correlated (PET: R²=0.98, p<0.0001; APD: R²=0.94, p<0.0001) (Fig.3). ΔV_Dwell decreased in eight patients (2 PET; 6 APD) (Fig.4) which indicated absorption of V_ABD; it was stable in nine patients (4 PET; 5 APD) (Fig.5) and increased in three (1 PET; 2 APD). Stable ΔV_EPF (ΔV_EPF=0) was observed in three PET patients, allowing us to explore its association with membrane transport status; notably, stable ΔV_EPF was associated with high glucose transport.

Conclusion

This pilot study demonstrated a new bioimpedance approach to monitor fluid changes between extra- and intraperitoneal compartments. If confirmed in a larger population, the method may provide a direct measurement of fluid transport across the peritoneal membrane.

Fig1