Assessment of degree of hydration in dialysis patients using whole body and calf bioimpedance analysis

• Published in: Journal of physics. Conference series Vol. 224; no. 1; p. 012124
• Main Authors: Zhu, F, Kotanko, P, Handelman, G J, Raimann, J, Liu, L, Carter, M, Kuhlmann, M K, Siebert, E, Leonard, E F, Levin, N W
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.04.2010
• Subjects: Blood pressure; Body size; Body weight; Electrical resistivity; Hemodialysis; Hydration; Physics
• ISSN: 1742-6596; 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/224/1/012124

Prescription of an appropriate post hemodialysis (HD) dialysis target weight requires accurate evaluation of the degree of hydration. The aim of this study was to investigate whether a state of normal hydration as defined by calf bioimpedance spectroscopy (cBIS) could be characterized in HD and normal subjects (NS). cBIS was performed in 62 NS (33 m/29 f) and 30 HD patients (16 m /14 f) pre- and post-dialysis to measure extracellular resistance. Normalized calf resistivity at 5 kHz (ρN,5) was defined as resistivity divided by body mass index. Measurements were made at baseline (BL) and at a state of normal hydration (NH) established following the progressive reduction of post-HD weight over successive dialysis treatments until the ρN,5 was in the range of NS. Blood pressures were measured pre- and post-HD treatment. ρN,5 in males and females differed significantly in NS (20.5±1.99 vs 21.7±2.6 10-2 Ωm3/kg, p>0.05). In patients, ρN,5 notably increased and reached NH range due to progressive decrease in body weight, and systolic blood pressure (SBP) significantly decreased pre- and post-HD between BL and NBH respectively. This establishes the use of ρN,5 as a new comparator allowing the clinician to incrementally monitor the effect of removal of extracellular fluid from patients over a course of dialysis treatments.