Clinical impact of residual function in haemodialysis.

The term residual renal function (RRF) refers to the small renal function activity persisting in patients affected by chronic renal failure in the uraemic phase. It is associated with better clinical features as well as better laboratory values (1). Nevertheless, RRF usually decreases with variable rates over time; in particular peritoneal dialysis is associated with a better preservation of RRF than haemodialysis.