Kidney Week

Abstract: SA-PO449

Identification of Body Fluid Distribution in Patients on Hemodialysis and Peritoneal Dialysis Using Whole-Body and Segmental Bioimpedance Analysis

Session Information

• Home Dialysis - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 802 Dialysis: Home Dialysis and Peritoneal Dialysis

Authors

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

Fansan Zhu, PhD

• Abbas, Samer R., Renal Research Institute, New York, New York, United States

Samer R. Abbas, MSc, PhD

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

Laura Rosales M., MD, MPH

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

Peter Kotanko, MD, FASN

Background

The understanding of fluid transport in dialysis patients is based on a two-compartment model between the whole body's extracellular volume (ECV) and the intravascular compartment. We developed a segmental method to measure ECV in the arm, trunk, and leg. This study aims to evaluate change in ECV in the segments of hemodialysis (HD, Fig.1) and peritoneal dialysis (PD, Fig. 2) patients during dialysis.

Methods

Twenty HD (9 females, age 68.7±24.4 year) and 19 PD patients (10 females, age 54.6±11.6 year) were studied. Whole body and segmental bioimpedance spectroscopy (Hydra 4200) were performed pre and post-treatment (Fig. 3). Changes in the whole body ECV (ΔECV_W) and in the arm (ΔECV_A), trunk (ΔECV_T), and leg (ΔECV_L) were estimated (post – pre ECV). Ultrafiltration volumes (UFV) were recorded. The difference between UFV and ΔECV_W was calculated (DIFF=UFV – ΔECV_W). The ratios of changes in segmental ECVs to UFV (2*ΔECV_A/UFV; ΔECV_T/UFV; and 2*ΔECV_L/UFV) were defined as effective removed volume (ERV, %).

Results

UFV in HD patients was larger compared to PD patients (2.65±0.83 L vs. 0.36±0.22 L, p<0.0001), but treatment time did not differ (3.82±0.67 h vs. 4.00 h, p=0.27). DIFF in HD was larger than in PD patients (Fig. 4). In HD patients, the mean of leg ERV (-44±45 %) was larger than in the trunk ERV (-29±20 %; p=0.23), as well as larger than in the arms (-4±28 %; p<0.01) (Fig. 5). In contrast, in PD patients, trunk ERV (-57±21%) was larger compared to ERV of leg (-33±26%, p=0.1) and arms (-9±55 %, p=0.07) (Fig. 6).

Conclusion

In HD patients, more than 40% of UFV was removed from the legs, while in PD patients more than 50% of UFV was removed from the trunk. These different fluid distributions may cause errors in the estimation of fluid removed by the whole body bioimpedance method. Fluid distribution models may further make a better understanding of fluid dynamics in patients treated with different dialysis modalities, and therefore, improve precision care.