Different pattern of fluid loss from the lower extremities in normohydrated and overhydrated stage 5 chronic-kidney-disease patients after haemodialysis.

Aim: It is unclear whether fluid is lost from each body segment in a similar manner during haemodialysis (HD) in normohydrated (NH) and overhydrated (OH) patients.

Methods: The authors measured changes in regional-body fluid compartments using segmental multifrequency bioelectrical impedance analysis before and after HD in 26 stage 5 chronic-kidney-disease patients. Patients were divided into NH and OH groups. Correlation between ultrafiltration (UF) amount and per cent changes in extracellular fluid (ECF)/total body water (TBW) ratios measured in five body segments were analysed in NH and OH groups.

Results: No differences were found between the two groups with respect to per cent decreases in body weight, TBW, or intracellular fluid levels. Correlation coefficients between UF amounts and per cent decreases in TBW, intracellular fluid and ECF were higher in the NH group than in the OH group. UF amounts were found to be correlated with per cent ECF/TBW decreases in all body segments in the NH group but, to be only correlated with per cent decreases in ECF/TBW(Left arm) and ECF/TBW(Trunk) in the OH group. Positive correlations were found between UF amounts and per cent ECF/TBW(Right leg) decreases (r = 0.66, P = 0.01), regardless of age in the NH group only.

Conclusion: NH and OH patients show different patterns of fluid loss from regional-body fluid compartments. This may be useful for determining patient hydration status.