# Kt/V from PRU

Quantify hemodialysis adequacy

### Questions

## About

Result 1 is calculated using the following formula:

Kt/V = (0.026 - PRU) - 0.460

Result 2 is calculated using the following formula:

Kt/V = (0.24 - PRU) - 0.276

Recall that:

Percent Reduction Urea (PRU) = (1 - [postdialysis BUN ÷ predialysis BUN]) X 100%

These equations are frequently used because of their simplicity, and though reasonably accurate, are generally felt to be inferior to the forumula used in our calculator entitled "Kt/V Daugirdas". Although using the PRU is useful as an epidemiologic tool, its utility in individual patients is more limited because of the considerable range of Kt/V that can be seen for any given PRU. Part of this variability is due to the fact that PRU does not take into account urea removal that occurs with ultrafiltration.

## References

Daugirdas JT.

Rapid methods of estimating Kt/V: three formulas compared.

ASAIO Transactions 1990, 36 (3): M362-4

Lowrie EG, Lew NL.

The urea reduction ratio (URR). A simple method for evaluating hemodialysis treatment. Contemp Dial Nephrol 1992; 12:11.

The Kt/V from PRU calculator is created by QxMD.

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