Monitoring of Intraperitoneal Fluid Volume during Peritoneal Equilibration Testing using Segmental Bioimpedance

Abstract

Background: Ultrafiltration failure and fluid overload are common in peritoneal dialysis (PD) patients. Knowledge of intraperitoneal volume (IPV) and time to peak IPV during a dwell would permit improved PD prescription. This study aimed to utilize trunk segmental bioimpedance analysis (SBIA) to quasi-continuously monitor IPV (IPVSBIA) during the peritoneal dwell. Methods: IPVSBIA was measured every minute using lower-trunk SBIA (Hydra 4200; Xitron Technologies Inc., CA, USA) in 10 PD patients during a standard 240-min peritoneal equilibration test (PET). The known dialysate volume (2 L) rendered IPVSBIA calibration and calculation of instantaneous ultrafiltration volume (UFVSBIA) possible. UFVSBIA was defined as IPVSBIA – 2 L. Results: Based on dialysate-to-plasma creatinine ratio, 2 patients were high, 7 high-average, and 1 low-average transporters. Technically sound IPVSBIA measurements were obtained in 9 patients (age 59.0 ± 8.8 years, 7 females, 5 African Americans). Drained ultrafiltration volume (UFVdrain) was 0.47 ± 0.21 L and correlated (r = 0.74; p < 0.05) with end-dwell UFVSBIA (0.55 ± 0.17 L). Peak UFVSBIA was 1.04 ± 0.32 L, it was reached 177 ± 61 min into the dwell and exceeded end-dwell UFVSBIA by 0.49 ± 0.28 L (95% CI: 0.27–0.7) and UFVdrain by 0.52 ± 0.31 L (95% CI: 0.29–0.76), respectively. Conclusion: This pilot study demonstrates the feasibility of trunk segmental bioimpedance to quasi-continuously monitor IPVSBIA and identify the time to peak UFVSBIA during a standard PET. Such new insights into the dynamics of intraperitoneal fluid volume during the dwell may advance our understanding of the underlying transport physiology and eventually assist in improving PD treatment prescriptions.

The role of segmental bioelectrical impedance technique in the assessment of intraperitoneal ultrafiltration volume with peritoneal dialysis patients

“…There is some difference with the results of Fan san Zhu et al. [ 12 ]. The possible reasons may be as follows.…”

Evidence on continuous flow peritoneal dialysis: A review

“…This may in theory result in damage to the peritoneal membrane at the catheter tip due to negative pressures. Yet, a system to control and/or monitor intraperitoneal volume during treatment seems important, for example, by measurement of intraperitoneal pressure (e.g., via the abdominal catheter after short cessation of the flow) or bioimpedance, 44 although it is questionable whether these techniques are accurate enough.…”

“…Increased intraperitoneal pressure due to overfilling was reported by Nourse et al in one pediatric patient, which was solved by peritoneal fluid drainage. However, the authors did not report which adverse events occurred due to the overfilling 44 18,28,35,36 .…”

“…As cultures revealed no infectious microorganism, this suggests occurrence of sterile perito- However, the authors did not report which adverse events occurred due to the overfilling. 44 Ultrafiltrate could be periodically or continuously drained during treatment, for example, by setting the…”

“…44 although it is questionable whether these techniques are accurate enough.Of note, 83% of CFPD studies used two single-lumen catheters or a double-lumen catheter (not commercially available), while prevalent PD patients have a single-lumen catheter. Thus far, it is unknown whether application of alternate in-and outflow with high flow rates via a single lumen catheter-as applied by Van Gelder (pigs), Roberts (pigs), Htay (patients), and Raj (patients)-can be a reasonable alternative to continuous flow via two catheter(s) (lumens).…”