Unmasking fluid overload in children on peritoneal dialysis: a multimodal diagnostic approach.

Background: This study aimed to assess fluid status in pediatric patients on peritoneal dialysis by combining ultrasonography and bioimpedance spectroscopy (BIS). It specifically focused on examining the changes in volume status following a 2-h dwell time ultrafiltration exchange and evaluating the reliability of these techniques.

Methods: Thirteen pediatric patients on peritoneal dialysis were enrolled in this study, and their hydration status was assessed clinically. In addition, 56 lung ultrasound measurements, inferior vena cava (IVC) collapsibility index assessments, and BIS evaluations were performed both before and after a 2-h dwell exchange using 2.27%/2.5% dextrose dialysate.

Results: The mean age of the patients was 8.6 ± 4.1 years, and eight of them (61.5%) were male. The IVC collapsibility index significantly increased (26.3 ± 10.0% vs. 44.4 ± 9.4%; p < 0.001), and the total number of B-lines significantly decreased (median 22 vs. 11.5; p < 0.001) after a 2-h dwell exchange using 2.27%/2.5% dextrose dialysate. A positive correlation was observed between the total number of B-lines and fluid overload measured using BIS both pre-dialysis (r = 0.504, p = 0.006) and post-dialysis (r = 0.528, p = 0.004). A significant reduction in the total number of B-lines was observed across all hydration groups after dialysis (p < 0.001). The area under the receiver-operating characteristic curve (AUC) for the total number of B-lines in predicting severe overhydration was 0.685 (p = 0.097) when assessed using BIS and 0.740 (p = 0.181) when assessed by weight.

Conclusion: Our results highlight marked changes in fluid status parameters from pre- to post-dialysis, underscoring the clinical value of combining lung ultrasonography and BIS for monitoring fluid overload in pediatric patients undergoing peritoneal dialysis.