When you begin dialysis treatments, whether hemodialysis or peritoneal dialysis (PD), you should begin to feel better as your blood is getting cleaned. To make sure you are getting adequate dialysis, your nephrologist will order lab work to see how well dialysis is working for you. If your doctor sees that your blood is not being adequately cleaned, changes can be made to help you get better treatments.
The urea reduction ratio (URR) is one way of measuring dialysis adequacy—how much waste is removed by hemodialysis. If you receive hemodialysis three times a week, each treatment should reduce your urea level (also called BUN or blood urea nitrogen) by at least 65 percent.
Kt/V, like URR, is a measure of dialysis adequacy.
For hemodialysis three times a week, K/DOQI (Kidney Disease Outcomes Quality Initiative) national guidelines recommend a delivered Kt/V of at least 1.2.
In continuous ambulatory peritoneal dialysis (CAPD), the guidelines recommend a weekly Kt/V of at least 2.0, taking into account any remaining kidney function along with the CAPD treatment. In PD, Kt/V is measured by collecting drained dialysate along with any urine you produce in a 24-hour period.
These lab tests are drawn monthly. For PD, the Kt/V is usually done quarterly. Ask your dialysis nurse what your values are each time. If your values do not reach adequate numbers, work with your healthcare team to raise your dialysis dose.
During hemodialysis, a blood pump is set to a constant speed to push your blood through the dialyzer and back to your body. Your doctor prescribes the blood flow rate. It’s usually between 300 and 500 mL/min (milliliters per minute). Ask your technician to show you how to see the blood flow rate on your machine. With many dialyzers, blood flow rates greater than 400 mL/min can increase the removal of toxins. Blood flow rate is limited by the size of your access, the tubing and the needles.
A hemodialysis machine monitors the pressure of your blood inside the tubing and dialyzer. Depending on the machine, arterial pressure is measured in one of two places. One is between your access and the blood pump (pre-pump arterial pressure). The other is between the blood pump and the dialyzer (post-pump arterial pressure).
An alarm will go off if the pressure is too high or too low, due to:
In the hemodialysis machine, venous pressure is measured between the dialyzer and your access. If your venous pressure rises from week to week, it could mean a narrowing of the blood vessels in your access. Caught early, this can be fixed.
A venous pressure alarm will go off it:
Ask your dialysis team what your arterial and venous pressure numbers should be.
The best judge of how you feel is you, but your doctor will also review your lab tests to see if you are receiving the most effective dialysis treatments.
This site is for informational purposes only and is not intended to be a substitute for medical advice from a physician.
Please check with a physician if you need a diagnosis and/or for treatments as well as information regarding your specific condition. If you are experiencing urgent medical conditions, call 9-1-1