Dialysis adequacy targets in continuous ambulatory peritoneal dialysis--higher is not necessarily better

Evidence for the recommendations by the Dialysis Outcomes Quality Initiative (DOQI) on peritoneal dialysis targets was obtained largely from observational studies showing improvement of clinical outcome with higher Kt/V. Recently published interventional studies--including the ADEMEX study and several studies from Asia--did not show significant improvement of outcome with increased peritoneal Kt/V or creatinine clearance. The possible reasons for lack of improvement might include the limitations of increased dialysis with regard to middle-molecule clearance and the harmful effects of excessive dialysis. The body of evidence suggests that a total Kt/V below 1.7 is associated with a poorer outcome. A minimal Kt/V target of 1.7 is suggested, with the dialysis prescription also being guided by other clinical parameters.