Kidney Week

Abstract: TH-PO664

Assessing the Hydration Status of Children with CKD and On Dialysis: A Comparison of Techniques

Session Information

• Pediatric Nephrology
  November 02, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Developmental Biology and Inherited Kidney Diseases

• 403 Pediatric Nephrology

Authors

• Eng, Caroline Siew yin, Hospital Tuanku Jaafar Seremban, SEREMBAN, Malaysia

Caroline Siew yin Eng,

• Shroff, Rukshana, Great Ormond Street Hospital for Children, London, United Kingdom

Rukshana Shroff,

Background

Fluid balance is pivotal in the management of children with chronic kidney disease (CKD) and on dialysis. Although many techniques are available to assess fluid status, there are few studies in children, and none of the techniques have been compared against each other or against cardiovascular outcome measures.

Methods

We performed a longitudinal study in 30 CKD children and 13 age-matched healthy controls (71 measurements) to determine a correlation between optimal weight by bioimpedance spectroscopy (Wt-BIS) and clinical assessment (Wt-CA). The accuracy of Wt-BIS (relative overhydration [Rel-OH]) was compared against indicators of fluid status and cardiovascular measures.

Results

There was poor agreement between Wt-CA and Wt-BIS in children on dialysis when compared to CKD5 or control subjects (p=0.01). We developed a modified chart to plot Rel-OH against systolic BP z-score for the appropriate representation of volume status and BP in children. 25% of measurements showed systolic BP >90^th percentile but not with concurrent overhydration. Rel-OH correlated with peripheral pulse pressure (p=0.03; R=0.3), higher NT-proBNP (p=0.02; R=0.33) and left ventricular end-diastolic diameter (p=0.05;R=0.38). Central aortic mean and pulse pressure significantly associated with the left ventricular end-diastolic diameter (p=0.03;R=0.47 and p=0.01;R=0.50 respectively), but not with Rel-OH. Systolic BP was positively associated with PWV z-score (p=0.04). 40% of children on HD and 30% on PD had increased LVMI.

Conclusion

BIS provides an objective method for the assessment of hydration status in children on dialysis. We noted a marked discrepancy between BP and hydration status in children on dialysis that warrants further investigation.

Relative overhydration (Rel-OH) against systolic blood pressure (SBP) Z-score.

Funding

• Clinical Revenue Support