Introduction: Fluid status assessment in patients undergoing hemodialysis (HD) remains a major clinical challenge, as no single reference method is currently available. Different tools, such as bioelectrical impedance spectroscopy (BIS), point-of-care ultrasound (PoCUS), and clinical assessment, explore distinct pathophysiological domains. The aim of this study was to evaluate the complementary role of different bedside tools assessing volume overload and hemodynamic congestion in HD patients. Materials and Methods: This was a cross-sectional pilot study including 15 prevalent HD patients. A multiparametric pre-dialysis assessment was performed using BIS, PoCUS (lung ultrasound B-lines, inferior vena cava, and portal vein Doppler), and clinical evaluation. Congestion biomarkers, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and carbohydrate antigen 125 (CA-125), were also analyzed. Exploratory descriptive agreement analyses using the weighted kappa coefficient, together with correlation analyses, were performed. Results: BIS identified volume overload in 80% of patients, compared to 26.7% by clinical assessment and 13.3% by PoCUS. Exploratory agreement analyses showed moderate concordance between clinical assessment and PoCUS (κ = 0.59), low concordance between clinical assessment and BIS (κ = 0.19), and very low concordance between BIS and PoCUS (κ = 0.06). PoCUS identified a subgroup of patients with ultrasound findings suggestive of hemodynamic congestion, all corresponding to mild congestion. NT-proBNP levels were associated with both clinical congestion and BIS-estimated volume overload (rho ≈ 0.67; p = 0.007), while CA-125 showed a positive correlation with volume overload (rho ≈ 0.58; p = 0.025). Conclusions: Different bedside tools identified divergent but complementary patterns of extracellular volume overload and hemodynamic congestion in HD patients. BIS, PoCUS, and clinical assessment should not be interpreted as equivalent or interchangeable tools, but rather as complementary methods exploring distinct physiological and hemodynamic domains. These exploratory findings support a multiparametric approach to fluid status evaluation and require confirmation in larger studies.
Bachouti et al. (Fri,) studied this question.