Advances in Understanding and Management of Residual Renal Function in Patients with Chronic Kidney Disease.

BACKGROUND: Residual renal function (RRF), defined as the ability of native kidneys to eliminate water and uremic toxins, is closely correlated with mortality and morbidity rates among patients receiving either peritoneal dialysis (PD) or hemodialysis (HD) via continuous clearance of middle-sized molecules and protein-bound solutes. Therefore, preserving RRF is considered to be one of the primary goals in managing patients with end-stage renal disease (ESRD).

SUMMARY AND KEY MESSAGES: In this article, we provide a review on the understanding and management of RRF in patients on dialysis. RRF may be estimated and measured by calculating the mean 24-hour urine creatinine level and urea clearance. Currently, several middle-sized molecules are reported but rarely used in practice. Many risk factors such as original renal diseases, dietary intake, and nephrotoxic agents impair RRF. Targeting such factors may halt the decline in RRF and offer better outcomes for patients on PD or HD. Except for in PD patients, RRF is a powerful predictor of survival in HD patients. RRF requires more clinical and research attention in the care of patients with ESRD on dialysis.