URR & KT/V

How Does the Kt/V Compare with the URR?

The Kt/V is mathematically related to the URR and is in fact derived from it, except that the Kt/V also takes into account two additional factors:

• Urea generated by the body during dialysis
• extra urea removed during dialysis along with excess fluid

Is a URR of 65 percent or a Kt/V of 1.2 good enough?

These dialysis adequacy guidelines were determined on the basis of studies in large groups of patients. These studies generally showed that patients with lower Kt/V and URR numbers had more health problems and a greater risk of death. However, the HEMO study showed that a Kt/V greater than 1.2 did not result in improved outcomes.

If a patient’s Kt/V is always above 1.2 and the URR is close to 65 percent, then the patient’s treatment is meeting adequacy guidelines. The patient’s URR may be a few points below 65 if the person has large fluid losses during dialysis.

FIND OUT MORE