Electrical stimulation in dialysis is still an open question

Design

Cochrane systematic review and random-effects meta-analysis, RoB 2 and GRADE assessed

Population

12 randomised trials, 439 participants randomised, 299 contributing data, haemodialysis units in eight countries

Primary outcome

life participation, cardiovascular outcomes, death, fatigue, pain, infection and vascular access problems

Effect

systolic BP MD 5.54 mmHg (95% CI −4.02 to 15.09); diastolic 2.72 (−2.85 to 8.29); resting heart rate 4.58 (−2.67 to 11.82), all low certainty

Muscle wasting in dialysis is common and consequential, exercise helps, and most patients cannot or will not do it — which is why passive neuromuscular electrical stimulation during a dialysis session is an attractive idea. This Cochrane review assessed whether it works.

Twelve randomised trials published between 2011 and 2025 met the criteria, across haemodialysis units in eight countries. Of 439 participants randomised across all arms, 348 were in eligible groups and 299 contributed to at least one meta-analysis. Intervention duration ranged from four to 20 weeks, and the stimulation parameters varied enormously: 5 to 100 Hz, 20 to 60 minutes a session, two to five sessions a week.

The results are mostly absences. Neuromuscular electrical stimulation may make little or no difference to systolic blood pressure (mean difference 5.54 mmHg, 95% CI −4.02 to 15.09), diastolic pressure (2.72, −2.85 to 8.29) or resting heart rate (4.58, −2.67 to 11.82), all low certainty. Effects on life participation (one study, 20 participants) and death (one study, 22 participants) are very uncertain. No study reported fatigue, pain, infection or vascular access problems — four of the outcomes the review considered critical. No study included peritoneal dialysis.

So the honest position is that this has been studied for fifteen years without anyone measuring what patients say matters. It is not that stimulation has been shown not to work; it is that the trials have not asked.

• Do not adopt neuromuscular stimulation as routine practice on this evidence
• If used locally, record fatigue and function — the outcomes no trial has reported
• Keep offering conventional intradialytic exercise where a patient will engage with it
• Note that nothing here applies to peritoneal dialysis

Why it matters

Fifteen years of trials have not measured the outcomes patients on dialysis say matter most.

Don't overread it

Absence of demonstrated benefit here reflects small, heterogeneous trials measuring the wrong things, not proof that stimulation is ineffective.

The statistics, in plain English

Every confidence interval here spans zero in both directions, so none of these results distinguishes benefit from harm. Low certainty means the true effect could differ substantially from the estimate; very low means the estimate carries almost no information. A single study with 22 participants reporting a risk ratio of 0.24 for death, interval 0.01 to 5.26, is not evidence about mortality in any direction. The absence of reported fatigue and pain outcomes is the most telling finding in the review.

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