Convective Dialysis Probably Reduces Death Risk in Kidney Failure

Key Clinical Takeaways:
• Convective dialysis probably lowers all-cause and cardiovascular mortality compared to standard haemodialysis.
• The treatment shows little to no difference in nonfatal heart problems, severe tiredness, or overall quality of life based on current evidence.
• Evidence updated to April 2025 draws from 62 studies involving 6,897 adult participants.

Evaluating Kidney Failure Treatments Through Convective Dialysis

People with kidney failure rely on treatments like dialysis to remove toxins and fluid when kidneys no longer function well enough to keep a person alive. Standard haemodialysis uses a machine to filter waste and extra water from the blood. Expanded haemodialysis upgrades this process with special filters, while convective dialysis uses a strong flow of water to push larger waste products out of the blood.

Convective dialysis includes three specific modalities: haemofiltration, which relies only on strong water flow; haemodiafiltration, which combines standard filtering with strong water flow; and acetate-free biofiltration, a form of haemodiafiltration using a special fluid to keep blood pressure stable. Researchers wanted to find out if these newer modalities outperform standard haemodialysis in reducing mortality and improving patient well-being.

Clinical Evidence From 62 Studies

To determine efficacy, researchers searched for studies comparing convective dialysis with standard haemodialysis in adults with kidney failure. They identified 62 studies with a total of 6,897 adult participants, with 54 of those studies comparing convective haemodialysis against standard haemodialysis across 6,525 adults. The analysis indicated that convective dialysis probably reduces the risk of death from any cause as well as from heart or blood vessel disease.

At the same time, convective dialysis probably results in little to no difference in nonfatal heart problems. It may result in little to no difference in severe tiredness, problems with the dialysis access point, hospital stays, or overall quality of life. Direct comparisons between the different types of convective therapies proved too small to show any meaningful differences.

Mortality Reductions and Convection Volume in Large Trials

In a collaborative individual patient data meta-analysis of five large randomised controlled trials including more than 4,000 patients, online haemodiafiltration reduces all-cause mortality and cardiovascular mortality, particularly cardiac mortality, compared to conventional haemodialysis. This clinical benefit remains consistent across patient and treatment characteristics. A graded relationship between achieved haemodiafiltration convection volume and mortality risk emerged, showing that higher convection volumes yield greater patient benefit.

These findings build upon the 2023 CONVINCE trial, which reported a reduction in all-cause mortality in favour of high-dose haemodiafiltration. It was noted that while single trials raise questions around clinical practice, implementation should rely on all available evidence combined with updated data on cost-effectiveness and patient-reported outcomes.

Researchers Seek More Evidence on Kidney Failure Treatment Effects

Confidence in the evidence remains moderate for the risk of death, cardiovascular death, and nonfatal heart problems. Researchers have less confidence in results concerning severe tiredness, access point problems, hospital stays, and overall quality of life due to small sample sizes in certain studies and inconsistent treatment setups. Future studies must focus on how these treatments directly affect the daily lives of adults living with kidney failure.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.