Fluid status in dialysis patients:continuous ambulatory peritoneal dialysis versus hemodialysis

Objective To compare the fluid status between continuous ambulatory peritoneal dialysis (CAPD) patients and hemodialysis (HD) patients.Methods Forty-five CAPD patients and 44 HD patients were included in the study,46 healthy adults were served as control group. Volume status such as extracellular water (ECW) was measured using a Xitron-4200 bioelectrical impedance assessment device and was normalized by patients' ideal weight which equals to height minus 105.Results The normalized ECW of CAPD patients was 0.2918±0.0423, which was higher than that of control group (0.2397±0.0192), pre-HD patients (0.2718±0.0362) and post-HD patients (0.2328±0.0345).The nECW of pre-HD patients was higher than that of control group,while after HD there was no significant difference.Besides,the distribution of body fluid (ECW/TBW) was significantly different among the four groups.There was no significant difference of the calculated dry weight between HD and CAPD patients.However,the difference between dry weight and actual body weight in CAPD patients [(2.6±2.4) kg] was significantly higher than that in post-HD patients [(0.3±2.5) kg].No difference of the weekly total fluid removal was found between CAPD and HD patients.Conclusion Extracellular water and the difference between dry weight and actual weight in CAPD patients were significantly higher than those of post-HD patients.It suggested that CAPD patients might be in a constant fluid overloaded state.The fluid overload in CAPD patients may be ascribe to high fluid and salt intake.