intradialytic neuromuscular electrical stimulation improves functional capacity and muscle strength in people receiving haemodialysis: a systematic review

Questions: Does neuromuscular electrical stimulation (NMES) applied during haemodialysis sessions improve functional capacity in people with end-stage renal disease? Does NMES used in this way also improve muscle strength, muscle mass/architecture, psychological outcomes, cardiovascular outcomes and biochemical variables? Does it have any adverse effects? Design: Systematic review of randomised controlled trials with meta-analysis. PubMed, Web of Science, Scopus and SPORTDiscus were searched from inception to 15 October 2019. Participants: Patients receiving haemodialysis for end-stage renal disease. Intervention: NMES administered during haemodialysis sessions versus control. Outcomes measures: Functional capacity, muscle strength, muscle mass, psychological outcomes, cardiovascular outcomes, biochemical variables and adverse events. Data analysis: Data were meta-analysed where possible and results were expressed as the pooled mean difference between groups with a 95% confidence interval. Results: Eight studies (221 patients) were included in the analysis. Overall, the methodological quality of the studies was fair to good. NMES improved functional capacity as assessed by the 6-minute walk distance test (MD 31 m, 95% CI 13 to 49) and peak workload attained in incremental exercise (MD 12.5 W, 95% CI 3.2 to 21.9). NMES increased knee extensor muscle strength (MD 3.5 kg, 95% CI 2.3 to 4.7) and handgrip strength (MD 2.4 kg, 95% CI 0.4 to 4.4). Muscle mass/architecture was not substantially affected. NMES was estimated to be beneficial for several domains of quality of life in several studies, although most of these estimates were imprecise. No benefits were found for cardiovascular outcomes. The available data did not establish any clear effects on cardiovascular outcomes or biochemical variables (dialysis efficiency, urea and creatinine). No major NMES-related adverse events were observed. Conclusions: NMES is safe, practical and effective for improving functional capacity and muscle strength in haemodialysis patients. Further research is needed to confirm the clinical relevance of these findings. Registration: PROSPERO CRD42018107323.