Kidney Week

Abstract: TH-PO298

Continuous Measurement of Intraperitoneal Volume Using Bioimpedance: Importance of Electrode Placement Sites

Session Information

• Peritoneal Dialysis: CVD, Fluid, Nutrition
  November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 703 Dialysis: 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,

• Villarama, Maricar, Renal Research Institute, New York, New York, United States

Maricar Villarama,

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

Peter Kotanko,

Background

Continuous monitoring of intraperitoneal volume (IPV) may benefit peritoneal dialysis (PD) patients, e.g. by determining the peak ultrafiltration volume (UFV). The aim of this study was to optimize the placement sites of bioimpedance electrodes.

Methods

Six PD patients (age 61.3±7.6 years, 5 males, weight 87.3±25 kg) were studied with two different electrode placement sites. In group A, we used 4 and in group B 8 standard ECG electrodes (3M Red Dot Electrode; locations shown in Fig. 1 A and B). Measurements were done with the patients in a sitting position and their legs placed horizontally. We used the Hydra 4200 bioimpedance device (Xitron Technologies) for continuous measurement during the PD session. The PD sessions comprised three phases: filling (dialysate volume 2 L), dialysate dwell time (4 hours), and draining. The drain volume was weighted; we assumed that 1 kg equals 1 L.

Results

The average drain volume was 2.3±0.3 L. 5 kHz resistance data were extracted to assess intraperitoneal fluid changes. While in group A the 3 treatment phases are not obvious (Fig. 2 A), they can be clearly discerned in group B (Fig. 2 B).

Conclusion

These results show that electrode placement is key to successful continuous IPV measurements. In setup A (Fig. 1 A), 2 resistors are in parallel and the interstitial resistance (R_IT) is smaller than the peritoneal resistance (R_P); hence the measurement provides information only about the interstitial space. In setup B (Fig. 1B), the current travels through the peritoneal cavity so that IPV changes translate into resistance changes. If corroborated in larger studies, setup B has the potential to evolve into a future standard.