Do Bioimpedance Measurements of Over-Hydration Accurately Reflect Post-Haemodialysis Weight Changes?

Abstract

Introduction: Bioelectrical impedance spectroscopy (BIS) devices are being used to determine ultrafiltration requirements to achieve target weight for haemodialysis (HD) patients. Pre-dialysis measurements are more convenient for both patients and staff. We wished to compare the changes in pre- and post-dialysis hydration measured by BIS with actual weight loss. Methods: We compared paired BIS measurements made pre and post HD using a BIS device based on a 3-compartmental model, designed to provide information on extracellular water (ECW) excess. Results: BIS was measured in 49 HD patients, 35 male (71.4%) with mean age 67.6 ± 14.2. Weight fell significantly from 69.2 ± 17.8 to 67.6 ± 17.4 kg, and BIS over hydration (OH) from 4.5 ± 3.3.4 to 3.4 ± 2.9 litres, and ECW from 16.8 ± 4.8 to 15.5 ± 4.4 litres, but there was no change in the amount of intracellular water. Weight loss correlated positively with the change in ECW, but exceeded the fall in OH; mean bias -0.58 (95% confidence limits -3.6 to 4.8 kg). Summary: We measured OH pre and post HD, but did not find that the change in OH correlated with changes in body weight. Although there was a correlation between changes in OH and ECW, there was none for weight. Our findings do not support total reliance on pre-dialysis BIS alone for assessing volume status in HD patients, but rather BIS should be considered an aid to clinical assessment of volume status.

Effect of Self‐Reported Distress Thermometer Score on the Maximal Handgrip and Pinch Strength Measurements in Hemodialysis Patients

“…We did not find any association between higher scores and loss of muscle mass. We measured muscle mass by bioimpedance, 32 and previous studies have reported differences using bioimpedance devices in HD patients, 7 , 33 and even though we allowed for reequilibration following the dialysis session, 34 further studies using DXA 35 or isotopic methods may be required to confirm our results.…”

Comparison of resting energy equations and total energy expenditure in haemodialysis patients and body composition measured by multi‐frequency bioimpedance

“…Patients with pacemakers, and other implantable cardiac devices, and those unable to stand to measure bioimpedance were excluded from the study. Measurements were performed in a standardized manner, after the mid‐week haemodialysis session, allowing appropriate time for redistribution of fluid between body compartments post‐dialysis . Previous studies have validated this device against dual electron X ray absorptiometry .…”

“…Measurements were performed in a standardized manner, after the mid-week haemodialysis session, 17,18 allowing appropriate time for redistribution of fluid between body compartments post-dialysis. 19,20 Previous studies have validated this device against dual electron X ray absorptiometry. 21 Lean body mass index (LBMI) and fat mass index (FMI) were calculated by lean body mass (LBM) and fat mass (FM) divided by height squared, respectively.…”

Low body cell mass index in hemodialysis patients: Association with clinical parameters and survival

“…1 In clinical practice, Body Composition Monitor ® measurements are made pre-HD due to its important role in the estimation of dry weight as well as extracellular excess fluid. 13,14 Bioimpedance spectroscopy offers reliable assessments of body composition and several studies 15,16 report body composition measurements made before the HD session. 15 Although some authors suggest that the measurement should be made after HD, these studies evaluated the differences in body composition, pre-and post-HD.…”