RenalShield · Clinical Adequacy Tool

Hemodialysis Clearance & Fluid Safety Calculator

Calculate your single-pool Kt/V (Daugirdas II), Urea Reduction Ratio (URR), and Ultrafiltration Rate (UFR) in mL/kg/hr. Understand whether your fluid removal rate stays safely below cardiovascular strain thresholds.

Educational Tool Only: This calculator helps patients and families understand dialysis adequacy numbers from monthly clinic lab sheets. It does not determine clinical prescriptions, dry weight targets, or dialyzer clearance adjustments. Discuss all lab trends with your nephrologist and care team.

Enter Treatment & Monthly Lab Values

Blood urea nitrogen before session
Drawn via slow-flow stop-pump protocol
Typical: 3.5 - 4.5 hours (or nocturnal)
Scale weight exiting the clinic
Total fluid volume pulled on the run

Clearance & Safety Summary

Single-Pool Kt/V
1.51
Target: ≥ 1.2 min (≥ 1.4 goal)
Urea Reduction Ratio (URR)
72.3%
Target: ≥ 65%
Ultrafiltration Rate (UFR)
8.9 mL/kg/hr
Safe (< 10 mL/kg/hr)
Equilibrated eKt/V
1.36
Post-rebound estimated clearance

Why Ultrafiltration Rate (UFR) Matters for Cardiac Health

In hemodialysis, removing waste (urea, potassium, toxins) requires blood flow and diffusion. But removing fluid (ultrafiltration) requires pulling water directly from your circulating plasma.

If fluid is pulled faster than your vascular beds can refill from muscle and tissues, your heart experiences temporary oxygen starvation known as myocardial stunning. Over years, high ultrafiltration rates cause progressive heart muscle stiffness and cardiovascular wear.

  • Safe Range (< 10 mL/kg/hr): Well-tolerated by most cardiovascular systems. Refill rate keeps pace with ultrafiltration.
  • Caution Range (10 – 13 mL/kg/hr): Moderate cardiovascular stress. Associated with post-dialysis fatigue, cramping, and mild blood pressure dips.
  • Critical Ceiling (> 13 mL/kg/hr): Strongly associated in nephrology literature (Flythe et al., 2011) with cardiovascular events, intradialytic hypotension, and chronic myocardial stunning.

Questions for Your Next Dialysis Care-Team Rounds

  • "What was my single-pool Kt/V and URR on my latest monthly lab report?"
  • "Is my current prescribed session length long enough to keep my ultrafiltration rate below 10–12 mL/kg/hr without crashing my blood pressure?"
  • "If I frequently feel wiped out or dizzy after my runs, could extending my treatment time by 15–30 minutes make fluid removal gentler?"
  • "Is my target dry weight still accurate, or have I gained or lost real lean muscle or body fat?"