Dialysis: Measuring How Well It Works - Adventist HealthCare

Dialysis: Measuring How Well It Works

Topic Overview

Dialysis removes urea and other waste products from the blood. To find out how well dialysis is working, you will have blood tests that look at the level of urea in your blood. Usually these tests are done once a month, at the beginning of your session and again at the end. Two measures show how well dialysis is working: urea reduction ratio (URR) and Kt/V.

Urea reduction ratio

One way to measure how well hemodialysis is removing urea from the body is to measure blood urea nitrogen (BUN) level. The BUN is measured before and after your treatment session. Then the two numbers are compared to see how much the urea level in the blood has decreased. This difference is called the urea reduction ratio (URR), and it is usually expressed as a percentage. An adequate dose of hemodialysis should result in an average URR of 65%.

Kt/V

Another way to measure the effectiveness of hemodialysis is to compare the amount of fluid that is cleared of urea during each dialysis session with the amount of fluid that exists in the body. This is called the Kt/V.

  • Kt represents the amount of fluid that is cleared of urea during each dialysis session. It is measured in milliliters per minute (mL/min).
  • V represents the volume of water a person's body contains.

The Kt/V is the most accurate measure of hemodialysis, because it also measures the amount of urea removed with excess fluid and takes into consideration other factors, such as weight loss during dialysis. An adequate dose of hemodialysis should result in an average Kt/V of 1.2.

What to think about

An adequate dose of dialysis can usually be delivered in 3 to 5 hours.

Related Information

Credits

Current as ofMarch 14, 2018

Author: Healthwise Staff
Medical Review: Anne C. Poinier, MD - Internal Medicine
Adam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Tushar J Vachharajani, MD, FASN, FACP - Nephrology

Disclaimer: The information contained in this website, and its associated websites, is provided as a benefit to the local community, and the Internet community in general; it does not constitute medical advice. We try to provide quality information, but we make no claims, promises or guarantees about the accuracy, completeness, or adequacy of the information contained in or linked to this website and its associated sites. As medical advice must be tailored to the specific circumstances of each patient and healthcare is constantly changing, nothing provided herein should be used as a substitute for the advice of a competent physician. Furthermore, in providing this service, Adventist HealthCare does not condone or support all of the content covered in this site. As an Adventist health care organization, Adventist HealthCare acts in accordance with the ethical and religious directives for Adventist health care services.

Find a Doctor

Find an Adventist HealthCare affiliated doctor by calling our FREE physician referral service at 800-642-0101 or by searching our online physician directory.

View Doctors

Set Your Location

Setting your location helps us to show you nearby providers and locations based on your healthcare needs.