kt_v_dialysis: Kt/V for Dialysis Adequacy (Daugirdas Formula)

In cliot: Clinical Indices and Outcomes Tools

Kt/V for Dialysis Adequacy (Daugirdas Formula)

Description

Calculates the single-pool Kt/V (spKt/V) for hemodialysis adequacy using the Daugirdas Second Generation formula. This metric quantifies the dose of dialysis delivered by measuring urea clearance normalized to the patient's total body water volume.

Usage

kt_v_dialysis(pre_bun, post_bun, duration_hours, uf_volume_liters,
              post_weight_kg)

Arguments

pre_bun	Numeric. Pre-dialysis Blood Urea Nitrogen (BUN) level (mg/dL or mmol/L). Units must match post_bun.
post_bun	Numeric. Post-dialysis Blood Urea Nitrogen (BUN) level (mg/dL or mmol/L). Units must match pre_bun.
duration_hours	Numeric. Duration of the dialysis session in hours.
uf_volume_liters	Numeric. Volume of ultrafiltrate removed during the session in Liters.
post_weight_kg	Numeric. Patient's post-dialysis weight in kilograms.

Details

The formula used is the Daugirdas Second Generation Logarithmic Estimate:

Kt/V = -ln(R - 0.008 \times t) + (4 - 3.5 \times R) \times \frac{UF}{W}

Where:

• R = Post-BUN / Pre-BUN

• t = Duration in hours

• UF = Ultrafiltration volume in Liters

• W = Post-dialysis weight in kg

Value

A list containing:

Kt_V_Score	The calculated Kt/V value.
Interpretation	Clinical interpretation based on the standard adequacy target (>= 1.2).

References

Daugirdas JT. Second generation logarithmic estimates of single-pool variable volume Kt/V: an analysis of error. J Am Soc Nephrol. 1993;4(5):1205-1213. doi:10.1681/ASN.V451205

Examples

# Example 1: Adequate Dialysis
# Pre 80, Post 25, 4 hours, 3L UF, 70kg
kt_v_dialysis(80, 25, 4, 3, 70)

# Example 2: Inadequate Dialysis
# Pre 80, Post 40, 3 hours, 2L UF, 80kg
kt_v_dialysis(80, 40, 3, 2, 80)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.