Observational Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. Jul 25, 2022; 11(4): 127-138
Published online Jul 25, 2022. doi: 10.5527/wjn.v11.i4.127
Concordance between bio-impedance analysis and clinical score in fluid-status assessment of maintenance haemodialysis patients: A single centre experience
Kamiti Muchiri, Joshua K Kayima, Elijah N Ogola, Seth McLigeyo, Sally W Ndung’u, Samuel K Kabinga
Kamiti Muchiri, Joshua K Kayima, Seth McLigeyo, Clinical Medicine and Therapeutics, University of Nairobi, Nairobi +254, Kenya
Elijah N Ogola, Department of Clinical Medicine and Therapeutics, University of Nairobi, Nairobi +254, Kenya
Sally W Ndung’u, Department of Public Health, University of Nairobi, Nairobi +254, Kenya
Samuel K Kabinga, East African Kidney Institute, University of Nairobi, Nairobi +254, Kenya
Author contributions: Muchiri K, Kayima JK, Ogola EN, McLigeyo S, and Kabinga SK designed and coordinated the study; Muchiri K performed all the study procedures; Ndung’u SW analysed and interpreted the data; Muchiri K, Kabinga SK, and Ndung’u SW wrote the manuscript; and all authors approved the final version of this article.
Institutional review board statement: The study was reviewed by the Kenyatta National Hospital/University of Nairobi Scientific and Ethical Review Committee and approved under proposal number P822/012/2018 prior to initiation.
Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: Data can be availed on request.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Samuel K Kabinga, MBChB, MD, Doctor, East African Kidney Institute, University of Nairobi, P.O. Box 30197, Nairobi +254, Kenya. kabingas@yahoo.com
Received: June 19, 2021
Peer-review started: June 19, 2021
First decision: July 31, 2021
Revised: September 19, 2021
Accepted: June 21, 2022
Article in press: June 21, 2022
Published online: July 25, 2022
Processing time: 395 Days and 21.4 Hours
ARTICLE HIGHLIGHTS
Research background

Assessment of fluid status in patients with chronic kidney disease (CKD) on haemodialysis (HD) is important to guide treatment. Objective methods of assessment fluid status in this population of patients are needed. In CKD patients on HD, bio-impedance analysis (BIA) is reliable in assessment of fluid status though not available in many clinical situations. Clinical assessments for fluid overload (FO) are more popular in practice, though the individual elements are imprecise and may underestimate FO. There is need to determine the performance of a locally-developed clinical score (CS) in fluid status assessment when evaluated against BIA.

Research motivation

This study was motivated by the need to derive a local method of assessing fluid status in patients on HD and determine how this method compares with the BIA.

Research objectives

The objectives of this study were to assess the hydration status of patients on maintenance HD using BIA and a CS, as well as to evaluate the performance of that CS against BIA in fluid status assessment.

Research methods

This was a single-centre, hospital-based cross-sectional study which recruited adult patients with CKD who were on maintenance HD. The patients were aged 18 years and above and had been on maintenance HD for at least 3 mo. Those with pacemakers, metallic implants, or bilateral limb amputations were excluded. Data on the participants’ clinical history, physical examination, and chest radiograph findings were collected. BIA was performed on each of the study participants using the Quantum® II bio-impedance analyser manufactured by RJL Systems together with the BC 4® software. In evaluating the performance of the CS, BIA was considered as the gold standard test.

Research results

From 100 patients on maintenance HD screened for eligibility, 80 were recruited into this study. Seventy-one (88.75%) patients were fluid overloaded when evaluated using BIA with mean extracellular volume of 3.02 ± 1.79 L as opposed to the forty-seven (58.25%) patients who had FO when evaluated using the CS (P < 0.0001, 95% confidence interval: 0.1758-0.4242). The best cut-off point identified for the CS was four with values > 4 indicating FO and values 4 indicating no FO. At this cut-off point, the CS had 63% and 78% sensitivity and specificity respectively. None of the factors evaluated for association with FO showed statistical significance on the multivariable logistic regression model.

Research conclusions

Fluid overload is very prevalent in patients on chronic HD at the Kenyatta National Hospital Clinical score detects less FO when compared with BIA. The sensitivity and specificity for the CS were 63% and 78% respectively. None of the factors evaluated for association with FO showed statistical significance on the multivariable logistic regression model.

Research perspectives

Almost 90% of the patients had FO by BIA, and 57.5% had gross FO. BIA diagnosed significantly more patients with FO than the CS. The CS had a sensitivity if 63% and a specificity of 78% at a cut-off of 4.