Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews Issue 1, 2013 on Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease.Patients with advanced progressive disease often experience muscle weakness, which can impact adversely on their ability to be independent and their quality of life. In those patients who are unable or unwilling to undertake whole-body exercise, neuromuscular electrical stimulation (NMES) may be an alternative treatment to enhance lower limb muscle strength. Programmes of NMES appear to be acceptable to patients and have led to improvements in muscle function, exercise capacity, and quality of life. However, estimates regarding the effectiveness of NMES based on individual studies lack power and precision.

OBJECTIVES

Primary objective: to evaluate the effectiveness of NMES on quadriceps muscle strength in adults with advanced disease. Secondary objectives: to examine the safety and acceptability of NMES, and its effect on peripheral muscle function (strength or endurance), muscle mass, exercise capacity, breathlessness, and health-related quality of life.

SEARCH METHODS

We identified studies from searches of the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), and Database of Abstracts of Reviews of Effects (DARE) (the Cochrane Library), MEDLINE (OVID), Embase (OVID), CINAHL (EBSCO), and PsycINFO (OVID) databases to January 2016; citation searches, conference proceedings, and previous systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials in adults with advanced chronic respiratory disease, chronic heart failure, cancer, or HIV/AIDS comparing a programme of NMES as a sole or adjunct intervention to no treatment, placebo NMES, or an active control. We imposed no language restriction.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on study design, participants, interventions, and outcomes. We assessed risk of bias using the Cochrane 'Risk of bias' tool. We calculated mean differences (MD) or standardised mean differences (SMD) between intervention and control groups for outcomes with sufficient data; for other outcomes we described findings from individual studies. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Eighteen studies (20 reports) involving a total of 933 participants with COPD, chronic respiratory disease, chronic heart failure, and/or thoracic cancer met the inclusion criteria for this update, an additional seven studies since the previous version of this review. All but one study that compared NMES to resistance training compared a programme of NMES to no treatment or placebo NMES. Most studies were conducted in a single centre and had a risk of bias arising from a lack of participant or assessor blinding and small study size. The quality of the evidence using GRADE comparing NMES to control was low for quadriceps muscle strength, moderate for occurrence of adverse events, and very low to low for all other secondary outcomes. We downgraded the quality of evidence ratings predominantly due to inconsistency among study findings and imprecision regarding estimates of effect. The included studies reported no serious adverse events and a low incidence of muscle soreness following NMES.NMES led to a statistically significant improvement in quadriceps muscle strength as compared to the control (12 studies; 781 participants; SMD 0.53, 95% confidence interval (CI) 0.19 to 0.87), equating to a difference of approximately 1.1 kg. An increase in muscle mass was also observed following NMES, though the observable effect appeared dependent on the assessment modality used (eight studies, 314 participants). Across tests of exercise performance, mean differences compared to control were statistically significant for the 6-minute walk test (seven studies; 317 participants; 35 m, 95% CI 14 to 56), but not for the incremental shuttle walk test (three studies; 434 participants; 9 m, 95% CI -35 to 52), endurance shuttle walk test (four studies; 452 participants; 64 m, 95% CI -18 to 146), or for cardiopulmonary exercise testing with cycle ergometry (six studies; 141 participants; 45 mL/minute, 95% CI -7 to 97). Limited data were available for other secondary outcomes, and we could not determine the most beneficial type of NMES programme.

AUTHORS' CONCLUSIONS

The overall conclusions have not changed from the last publication of this review, although we have included more data, new analyses, and an assessment of the quality of the evidence using the GRADE approach. NMES may be an effective treatment for muscle weakness in adults with advanced progressive disease, and could be considered as an exercise treatment for use within rehabilitation programmes. Further research is very likely to have an important impact on our confidence in the estimate of effect and may change the estimate. We recommend further research to understand the role of NMES as a component of, and in relation to, existing rehabilitation approaches. For example, studies may consider examining NMES as an adjuvant treatment to enhance the strengthening effect of programmes, or support patients with muscle weakness who have difficulty engaging with existing services.

Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease

BACKGROUND

Patients with progressive diseases often experience muscle weakness, which impacts adversely on levels of independence and quality of life. In those who are unable or unwilling to undertake traditional forms of exercise, neuromuscular electrical stimulation (NMES) may provide an alternative method of enhancing leg muscle strength. Programmes appear to be well tolerated and have led to improvements in muscle function, exercise capacity and quality of life. However, estimates regarding the effectiveness of NMES from individual studies lack power and precision.

PRIMARY OBJECTIVE

to evaluate the effectiveness of NMES for improving muscle strength in adults with advanced disease.

SECONDARY OBJECTIVE

to examine the acceptability and safety of NMES, and changes in muscle function (strength or endurance), muscle mass, exercise capacity, breathlessness and health-related quality of life.

SEARCH METHODS

Studies were identified from searches of The Cochrane Library, MEDLINE, EMBASE, CINAHL and PsycINFO databases to July 2012, citation searches, conference proceedings and previous systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults with advanced chronic obstructive pulmonary disease (COPD), chronic heart failure, cancer or human immunodeficiency virus/acquired immunodeficency syndrome (HIV/AIDS) comparing a programme of NMES as a sole or adjunct intervention to no treatment, placebo NMES or an active control. We imposed no language restriction.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on study design, participants, interventions and outcomes. We assessed risk of bias using the Cochrane Collaboration's tool. We calculated mean differences (MD) or standardised mean differences (SMD) between intervention and control groups for outcomes with sufficient data; for other outcomes we described findings from individual studies.

MAIN RESULTS

Eleven studies involving a total of 218 participants met the inclusion criteria across COPD, chronic heart failure and thoracic cancer. NMES significantly improved quadriceps strength by a SMD of 0.9 (95% confidence interval (CI) 0.33 to 1.46), equating to approximately 25 Newton metres (Nm) (95% CI 9 to 41). Mean differences across various walking tests, favouring NMES, were 40 m (95% CI -4 to 84) for the six-minute walk test, 69 m (95% CI 19 to 119) for the incremental shuttle walk test and 160 m (95% CI 34 to 287) for the endurance shuttle walk test. Limited evidence was available for the assessment of other secondary outcomes.

AUTHORS' CONCLUSIONS

NMES appears an effective means of improving muscle weakness in adults with progressive diseases such as COPD, chronic heart failure and cancer. Further research is required to clarify its place in clinical practice, by determining the optimal parameters for a NMES programme, the patients most likely to benefit, and its impact on morbidity and service use.

Fatigue in COPD: Prevalence and effect on outcomes in pulmonary rehabilitation

Patients with chronic obstructive pulmonary disease (COPD) complain of dyspnea and fatigue. We sought to estimate the prevalence of high fatigue in this population and to determine whether individuals with high fatigue had a different response to pulmonary rehabilitation. This observational study was embedded within a randomized trial. Participants underwent 3 months of pulmonary rehabilitation including education and exercise training. We divided 251 individuals into low and high fatigue groups using population normal scores of the SF-36 vitality domain. Baseline data included spirometry, 6-minute walk distance (6MWD), peak exercise capacity, constant workrate cycling endurance time, and questionnaires including the St. George’s and Chronic Respiratory questionnaires (SGRQ, CRQ). The response to pulmonary rehabilitation was evaluated using changes in these measures at 3 months and 1 year after entry. High fatigue was present in 97/251 (39%) of patients. High fatigue patients were younger, had more depressive symptoms, greater dyspnea and poorer SGRQ scores (p < 0.01). They also had lower 6MWD, endurance times, and peak volume of oxygen consumption (VO2; p < 0.05). Patients in both groups improved similarly in their dyspnea, the 6MWD and endurance time. High-fatigue patients had greater improvements in both the CRQ fatigue (by 0.74 more points) and the SGRQ scores (by 6.0 points; p < 0.01), with clinically significant gains maintained at 1 year. This study suggests that high levels of fatigue is a common feature in patients with COPD. They have a lower exercise capacity and a lower health status. However, they benefit from pulmonary rehabilitation.