When is the best time to start dialysis?

To find out whether someone is at risk of kidney failure or already has it, people with chronic kidney disease have regular check-ups. Doctors look for the symptoms listed above. They also measure the glomerular filtration rate (GFR) to monitor how well the kidneys are working.

People with healthy kidneys have a GFR of 85 to 135 mL/min/1.73 m² of body surface area. This value decreases with age – that’s normal and isn’t necessarily a sign of kidney disease.

But if the kidneys become increasingly weaker in someone with chronic kidney disease, the GFR will continue to drop. The point at which dialysis become necessary isn’t determined by one specific GFR value. The symptoms that could be signs of kidney failure play a much more decisive role – or if there are major changes in blood pressure or fluid imbalances. If there are no such symptoms, dialysis can still be put off. The typical symptoms usually start to occur at a GFR of 5 to 10 mL/min/1.73 m² though.

One study has looked into the question of when dialysis should ideally start. Over 800 adults with advanced chronic kidney disease took part in the study. They were divided into two groups: In one group, dialysis was started earlier – on average at a GFR of 9 mL/min/1.73 m². In the other group, dialysis was started later. There the GFR had already dropped to 7.2 mL/min/1.73 m² on average.

The comparison of the two groups showed no differences between starting dialysis earlier and later: For example, there was no difference in terms of deaths or heart attacks. Infections of the arteriovenous fistula (shunt, see below) were also equally common.

So it’s still possible to wait a little and use the time to carefully prepare for the dialysis if there are no symptoms that make it an urgent need.

Dialysis is a treatment that you have for the rest of your life and it becomes a part of your everyday routine. Even the decision of which method is the best for you personally will take some time to make. That also applies to the preparations such as the surgical procedures that are necessary. For peritoneal dialysis, a catheter needs to be inserted into the abdominal cavity and attached to the abdominal wall. After a recovery period of two to four weeks, peritoneal dialysis can be started. For hemodialysis, an arteriovenous fistula (shunt) needs to be created using surgery. This is a connection between a vein and an artery in the forearm that is used to access the bloodstream in hemodialysis. It’s best to plan the procedure several months before starting dialysis. This is because several examinations need to be done first, and the shunt needs several weeks to develop so that it can be used over the long term.

Creating a shunt apparently works better if you are first transferred to a kidney specialist (nephrologist) long enough before dialysis is started. That is what researchers from the Cochrane Collaboration found based on 15 studies with a total of about 5,600 participants. Complications such as shunt infections were less common too. By analyzing other studies, the researchers also found out that life expectancy increases when a kidney specialist is involved early on.