Effect of acetate and bicarbonate dialysate on whole body bioimpedance (BIS) and segmental (thoracic) bioimpedance in hemodialysed (HD) patients.

There are sparse data about the influence of dialysis itself on bioimpedance measurement. The aim of this study was to evaluate the influence of dialysis without ultrafiltration on bioimpedance of thorax and bioimpedance of the whole body in hemodialysed patients. Isovolemic HD was performed during the first hour of dialysis session, using bicarbonate and then acetate dialysate. Thoracic impedance, whole body bioimpedance, blood pressure and blood density were measured. After bicarbonate dialysis significant TI lowering was observed with simultaneous R increase. There was a significant blood density lowering. Acetate hemodialysis caused no significant changes in TI but significant increase in R values. Blood density did not change after acetate HD. The influence of other factors, not only hydration status changes, must be considered in interpretation of bioimpedance measurement analysis.