The cardiovascular morbidity and mortality of chronic haemodialysis patients is markedly influenced by fluid status. We evaluated the possibilities of dual-frequency bioimpedance spectroscopy to assess the fluid status and specification of dry weight. We examined fifty-seven patients, who were included in the chronic haemodialysis programme at our workplace. Measuring was repeatedly performed after the haemodialysis session. A dual-frequency bioimpedance spectroscopy (DBIA) analyser (Inbody 230, Biospace Co. Ltd, Seoul, Korea) was used to measure body composition, i.e. fat, lean mass and total body water content. The median of difference between measuring was 0.37 % of total body water (TBW). All patients were clinically and radiologically examined before the haemodialysis; blood pressure values were monitored. The patients were divided into normovolemic and hypervolemic. The first subgroup of 31 normovolemic patients with arterial pressure under 140/90 and the second subgroup of 26 clinically or radiologically hypervolemic and all hypertensive patients were compared by DBIA against each other. We used the Student’s t-test for sets with different variability. A highly significant difference (p < 0.001) in body water fraction (TBW/body weight) was detected. The median of TBW/BW in normovolemic and hypervolemic patients was 48.1 % and 61.1 % respectively. Later we considered TBW/ BW in various BMI subgroups and found the same results. We commend its use to specify dry weight, particularly in hypertensive patients and patients with frequent intradialytic hypotension.

Department of Internal Medicine and Hepatogastroenterology Faculty Hospital and Faculty of Medicine Masaryk University Brno

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