Residual renal function in children on haemodialysis and peritoneal dialysis therapy

Residual renal function was studied in 28 haemodialysis (HD) and 31 peritoneal dialysis (PD) patients aged 1-20 years observed over 6-43 (median 19) months. After the start of dialysis urine volume (UV) decreased to 57%, 46% and 26% of initial mean values in HD patients after 6, 12 and 24 months, respectively. In PD patients the corresponding figures were 57%, 69% and 62%. Mean UV calculated from all individual mean UV measurements observed was higher in PD than HD patients (954 vs. 537 ml/m2 per 24 h, P < 0.01). A better conservation of diuresis in PD patients was also suggested by a significantly longer persistence of a UV greater than 500 ml/m2 per 24 h compared with HD patients. Cox proportional hazard analysis identified dialysis modality and pre-dialysis UV of less than 1,000 ml/m2 per 24 h as the only significant risk factors for UV survival. However, the decline of UV per time was similar in both modes of treatment. No significant changes of glomerular filtration rate were observed during both HD and PD treatment.