Do You Continue to Make Urine After Starting Dialysis?

Many patients will continue to produce urine even after starting dialysis. Making urine doesn't necessarily mean you don't need dialysis, however. The decision to initiate and maintain dialysis is based on multiple factors including lab tests and the patient's symptoms and not necessarily on the volume of urine one makes.

This article discusses urine production after starting dialysis, what it means, and how it is related to renal health.

Urine Production After Starting Dialysis

Unless your kidneys have completely shut down and the glomerular filtration rate (GFR) has gone down to absolute zero, you will probably still make urine after you start dialysis. This is known as residual renal function. In simple terms, it means you still have some kidney function, though it could be a very small fraction of what normal kidney function is. 

Factors that determine whether you might preserve residual renal function could include:

• Type of dialysis: in general, patients on peritoneal dialysis will tend to make urine from their kidneys longer than patients on hemodialysis.
• Cause: The cause of your kidney failure can also make a difference.
• Blood pressure control: Drops in blood pressure will tend to accelerate the loss of one's residual renal function.
• Medications: Certain ones could help your cause, while others could hurt (see below).
• Race: Non-White race is associated with a faster loss of residual kidney function.
  

It's Important to Preserve Residual Renal Function

As insignificant as it might seem, residual renal function is a big deal, and maintaining it is important.

These are some reasons why maintaining even a little kidney function after someone gets started on dialysis could make a big difference:

1. Patients who have significant residual renal function tend to live longer. Multiple studies have corroborated this.
2. Patients with intact residual renal function are more likely to receive an adequate dosage of dialysis. (Like any other medication, there is a certain minimum amount/dose of dialysis that one needs to receive to get its benefits.)
3. Quality of life is better. This is partly related to the patient's ability to get away with less strict dietary restrictions. They can also be a little more liberal with their fluid intake.
   

How to Preserve Residual Renal Function for Longer

This is an active area of research in nephrology. So far, researchers know that certain interventions can help preserve residual renal function better and longer. This might translate into a longer lifespan and a better quality of life for dialysis patients. Some of these interventions are:

• Good blood pressure control
• Controlling blood sugar if you have diabetes
• Use of certain medications, called ACE inhibitors, has been shown to help
• Avoiding certain medications that are known to be toxic to the kidneys, like nonsteroidal anti-inflammatory drugs (NSAIDs), aminoglycosides, Amphotericin B, etc.
• Considering starting kidney failure patients preferentially on peritoneal dialysis (called the peritoneal dialysis-first strategy, which remains a subject of debate)
• There are suggestions from some studies that a gradual incremental increase of hemodialysis might lead to better preservation of residual renal function

Summary

If you continue to produce urine after starting dialysis, it's an indication of residual renal function. This means your kidneys are still working to some extent.

Maintaining renal function is important because it can help improve your quality of life and may help extend your life. You can help preserve your renal function by keeping your blood pressure under control, taking medications as prescribed by your healthcare provider, and controlling your blood sugar.

Consider yourself lucky if you still continue to make some urine after starting dialysis. Even though it might seem insignificant, having even a little bit of urine output could make a big difference to your life expectancy as well as quality of life.