Dialysis Adequacy and Residual Kidney Function

Dialysis adequacy refers to the effectiveness of haemodialysis or peritoneal dialysis in removing toxins, maintaining fluid balance and preserving long‐term health in patients with end‐stage renal disease. Central to this concept is residual kidney function (RKF), the remaining native glomerular filtration and urine output that continues to clear solutes and fluid between dialysis sessions. RKF contributes significantly to middle‐molecule and protein‐bound toxin removal, volume control and nutritional stability, and is strongly linked to better survival, fewer cardiovascular events and improved quality of life. Contemporary practice aims to personalise dialysis prescriptions according to patient size, comorbidities and the rate of RKF decline, with incremental or infrequent regimens increasingly adopted to preserve residual function. Accurate assessment of adequacy typically employs metrics such as Kt/Vurea alongside interdialytic urine volume, and relies on careful monitoring of blood pressure, fluid status and nutritional markers. Global research continues to refine strategies that balance the removal of uraemic toxins with minimisation of intradialytic hypotension and unintentional volume depletion, seeking to extend the benefits of RKF for as long as possible.

Research from Nature Portfolio

Recent observational data have demonstrated that initiating peritoneal dialysis with fewer daily exchanges—known as incremental peritoneal dialysis—can slow the progression to anuria without compromising patient or technique survival. In a large single‐centre cohort study, patients who began with one or two daily exchanges maintained higher residual renal function and exhibited a 39 % lower risk of developing anuria compared with those on full‐dose regimens. Survival outcomes, episodes of peritonitis and hospital admission rates were similar between groups, supporting a tailored stepwise increase in dialysis dose as RKF declines.

Dialysis Adequacy and Residual Kidney Function publication trend

The graph below shows the total number of articles in dialysis adequacy and residual kidney function across all publications each year (not limited to Nature Index journals).

Technical terms

Dialysis adequacy: A measure of how effectively dialysis clears toxins and fluid, often quantified by Kt/Vurea or urea clearance.

Residual kidney function (RKF): The remaining glomerular filtration and urine output in dialysis patients that contributes to solute and fluid removal.

Kt/Vurea: A dimensionless index representing dialysis efficacy, where K is dialyser clearance, t is treatment time and V is patient’s volume of distribution of urea.

Incremental dialysis: A strategy of initiating dialysis with lower frequency or dose, increasing as RKF decreases.

Anuria: The absence of urine production, often defined as urine output below 100 mL per day.

Bio‐impedance spectroscopy: A non‐invasive technique to estimate body fluid compartments by measuring electrical resistance through tissues.

References

1. Bio-impedance spectroscopy added to a fluid management protocol does not improve preservation of residual kidney function in incident hemodialysis patients in a randomized controlled trial. Kidney International (2023).
2. Incremental Peritoneal Dialysis May be Beneficial for Preserving Residual Renal Function Compared to Full-dose Peritoneal Dialysis. Scientific Reports (2019).
3. IHDIP: a controlled randomized trial to assess the security and effectiveness of the incremental hemodialysis in incident patients. BMC Nephrology (2019).