Residual renal function in incremental haemodialysis

Area of Science:

• Nephrology
• Urea Kinetic Modeling
• Dialysis Therapy

Background:

• Equivalent renal clearance (EKR) and standard clearance (stdK) are continuous measures of urea clearance incorporating residual renal function (RRF).
• RRF is considered qualitatively superior to dialysis when assessed by equivalent urea clearance.
• Current KDOQI 2015 guidelines provide instructions for stdKt/V calculation and targets but lack defined EKR targets.

Purpose of the Study:

• To evaluate the efficacy of EKR/V and stdKt/V in describing haemodialysis urea clearance.
• To introduce and assess a new therapeutic index, adjusted total EKR/V (EKR/V a).
• To determine if adjusted EKR/V targets can facilitate less frequent incremental dialysis.

Main Methods:

• Calculated stdKt/V using classic and Daugirdas models, emphasizing renal contribution.
• Determined EKR/V with nominal and adjusted renal clearance values.
• Generated new dialysis prescriptions with varying continuous clearance targets using a computer program.

Main Results:

• Daugirdas stdKt/V was 7.5% higher than classic stdK/V in patients with RRF.
• Adjusted EKR/V was 14.4% higher than unadjusted EKR/V.
• Flexible weighting of RRF contribution is achievable with EKR/V by adjusting renal clearance.

Conclusions:

• Standard Kt/V is suboptimal for describing haemodialysis urea clearance.
• EKR/V provides a more sensible evaluation of RRF's role in dialysis.
• Utilizing adjusted EKR/V as a target enables less frequent incremental dialysis sessions.