Current clinical opinion supports the recommendation that total solute clearance in paediatric patients should meet or exceed that in the guidelines for adults of a combined urinary and peritoneal Kt/V urea value per week of 1.8 [
19] or 1.7 [
10] or a creatinine clearance of 50 L/week per 1.73 m
2 body surface area. In adult anuric patients a minimum peritoneal Kt/V urea value of 1.7 and an optimal target of 1.8 is suggested by Lo et al., based on survival data [
34]. A previous interventional study by the same group clearly demonstrated increased clinical problems, including severe anaemia in patients with a total Kt/V of < 1.7, but no difference in survival outcome between patients with a Kt/V maintained above 2 and those with a value between 1.7 and 2.0, with the difference in Kt/V accounted for by increasing peritoneal clearance only [
35]. The Adequacy of Peritoneal Dialysis in Mexico (ADEMEX) trial measured both peritoneal creatinine clearance and urea clearance as determinants of small-solute clearance and found no difference in 2-year survival rates between the control group and an intervention group with significantly greater clearances after adjusting for factors known to affect survival [
36]. However, the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) clearly identified an increase in the relative risk of death in anuric PD patients if the Kt/V urea value was < 1.5/week and creatinine clearance was < 40 L/week per 1.73 m
2 [
37]. There are no comparable mortality data for children, but the Network 1 Clinical Indicators Project reporting on clinical morbidity in paediatric dialysis patients found that, in a small group of well-dialysed patients on either HD or PD, the exceeding of recommended adequacy guidelines did not influence morbidity [
38]. Indeed, in children on PD, a Kt/V value of > 2.75 was associated with increased albumin losses, which may have an adverse effect on nutrition and growth [
39].