Dialysis Efficacy Assessment

Primary Measurement Method

The delivered dose of dialysis should be measured using Kt/V, with measurements performed at least monthly for all hemodialysis patients, as recommended by the American Journal of Kidney Diseases 1, 2

Single-pool Kt/V (spKt/V) is the preferred measure, calculated through formal urea kinetic modeling from pre- and post-dialysis blood urea nitrogen (BUN) samples, with a minimum target spKt/V of 1.2 per dialysis session for thrice-weekly treatments, according to the American Journal of Kidney Diseases 1, 3
Equilibrated Kt/V (eKt/V) accounts for post-dialysis urea rebound and provides a more accurate assessment, with a minimum target of 1.0, as stated by the American Journal of Kidney Diseases 2
Both pre- and post-dialysis BUN samples must be drawn during the same treatment session and analyzed together to minimize interassay variability, as recommended by the American Journal of Kidney Diseases 2
Monthly measurements are mandatory for quality assurance, according to the American Journal of Kidney Diseases 1, 2, 5

Total weekly Kt/V of at least 2.0 is recommended for CAPD patients, with total creatinine clearance of at least 60 L/week/1.73 m² for high/high-average transporters and 50 L/week/1.73 m² for low/low-average transporters, as stated by the American Journal of Kidney Diseases 6
All dialysate effluent should be collected over 24 hours with simultaneous timed urine collection, and urea and creatinine concentrations should be measured in pooled dialysate and urine samples, according to the American Journal of Kidney Diseases 7

Residual kidney urea clearance (Kr) should be measured from timed urine collection at regular intervals, and included in adequacy calculations, as recommended by the American Journal of Kidney Diseases 8, 5
Urine output alone does not accurately predict residual kidney function and should not be used as the sole determinant, according to the American Journal of Kidney Diseases 8, 5

Normalized protein catabolic rate (nPCR) should be calculated from urea generation rate, which should be 1.0-1.2 g/kg/day, and monitored longitudinally, as recommended by the American Journal of Kidney Diseases 9

Clinical symptoms alone are unreliable for assessing dialysis adequacy; quantitative measurements are essential, as stated by the American Journal of Kidney Diseases 1, 3
Access recirculation during post-dialysis sampling will falsely elevate Kt/V, leading to undetected underdialysis, according to the American Journal of Kidney Diseases 4

Delivered dose should be compared to prescribed dose monthly to identify problems with vascular access, blood pumps, or dialysate delivery, as recommended by the American Journal of Kidney Diseases 8, 5
Dialyzer function should be monitored through total cell volume (TCV) measurements or ionic clearance, rejecting dialyzers with >10% clearance loss, according to the American Journal of Kidney Diseases 10