For licensed healthcare professionals only. Not a diagnostic tool. See full disclaimer.
Kt/V (Dialysis Adequacy)
Input
mg/dL
mg/dL
L
kg
hours
Kt/V
—
Urea Reduction Ratio
—
About
Kt/V is the primary measure of hemodialysis adequacy. It quantifies the fractional clearance of urea during a dialysis session, where K = dialyzer clearance, t = time, and V = volume of distribution of urea. The Daugirdas second-generation formula accounts for ultrafiltration and urea generation during dialysis. KDOQI guidelines recommend a minimum single-pool Kt/V of ≥ 1.2 for thrice-weekly hemodialysis.
Formula
Kt/V = −ln(R − 0.008 × t) + (4 − 3.5 × R) × UF/W
R = Post-dialysis BUN / Pre-dialysis BUN
t = dialysis time (hours), UF = ultrafiltration (L), W = post-dialysis weight (kg)
URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100
Interpretation
| Kt/V | URR | Interpretation |
|---|---|---|
| ≥ 1.4 | ≥ 70% | Excellent |
| 1.2 – 1.4 | 65–70% | Adequate (target) |
| 1.0 – 1.2 | 60–65% | Borderline |
| < 1.0 | < 60% | Inadequate |
FAQ
Disclaimer
For educational and informational purposes only. Not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional.