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Calcimator

Dialysis Adequacy Calculator

Calculate Kt/V and Urea Reduction Ratio (URR) to assess hemodialysis adequacy using the Daugirdas second-generation formula.

Inputs

Results

Single-Pool Kt/V

1.37

Urea Reduction Ratio68.75%
Adequate Dialysis1
Kt/V (simplified)1.16
Weekly Kt/V (3x/week)4.11
How to Use This Calculator
  1. Enter the pre-dialysis BUN (blood urea nitrogen) in mg/dL.
  2. Enter the post-dialysis BUN after the treatment session.
  3. Input the dialysis session duration in hours.
  4. Enter the ultrafiltration volume in liters removed during treatment.
  5. Review the Kt/V value — a Kt/V ≥ 1.2 per session is the standard adequacy target.

How the result changes with Pre-Dialysis Urea (mg/dL)

Pre-Dialysis Urea (mg/dL)Single-Pool Kt/V
390.56
1121.77
1992.49
2712.94

What each input means

Pre-Dialysis Urea (mg/dL)
Blood urea nitrogen level before dialysis session.
Post-Dialysis Urea (mg/dL)
Blood urea nitrogen level after dialysis session.
Dialysis Time (hours)
Duration of the dialysis session.
Ultrafiltration Volume (liters)
Volume of fluid removed during dialysis.
Pre-Dialysis Weight (kg)
Patient weight before the dialysis session.

What each result means

Single-Pool Kt/V
Target: >= 1.2 per session for thrice-weekly dialysis.
Urea Reduction Ratio
Target: >= 65%.
Adequate Dialysis
1 = adequate (Kt/V >= 1.2), 0 = inadequate.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Pre-Dialysis Urea (mg/dL) = 80, Post-Dialysis Urea (mg/dL) = 25, Dialysis Time (hours) = 4, Ultrafiltration Volume (liters) = 2.5 = 5 input(s) provided
  2. Calculate Single-Pool Kt/V
    Single-Pool Kt/V = max(0
    1.37 = 1.37
  3. Calculate Urea Reduction Ratio
    Urea Reduction Ratio = max(0
    68.75 = 68.75
  4. Calculate Adequate Dialysis
    Adequate Dialysis
    1 = 1

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