Neuromuscular electrical stimulation to improve exercise capacity in patients with severe COPD: a randomised double-blind, placebo-controlled trial

Effect of adding neuromuscular electrical stimulation for patients with moderate to severe chronic obstructive pulmonary disease: Systematic review and meta-analysis

BACKGROUND

Healthcare providers have faced challenges for patients with moderate and severe chronic obstructive pulmonary disease (COPD) in conducting their pulmonary rehabilitation due to dyspnea and exercise intolerance. Neuromuscular electrical stimulation (NMES) has been used to improve the muscle group's power and endurance without adding pulmonary workload, which might be used as a potential adjuvant rehabilitation method and thus to improve patients' pulmonary functions.

METHODS

This was a systematic review and meta-analysis of randomized controlled trials. Data were retrieved from PubMed, CINAHL, Academic Search Complete, Cochrane Library, and Airiti Library databases from the inception of the database to December 2022. The Cochrane Collaboration tool was used to assess the risk of bias. Two reviewers independently assessed, extracted, and appraised the included studies. Then, the grading of recommendations, assessment, development, and evaluation (GRADE) methodology was used for assessing the certainty of evidence. The pooled estimates were calculated using a random-effects model.

RESULTS

In total, 19 studies involving 589 moderate to severe COPD patients were analyzed. Compared with controls, adding NMES to pulmonary rehabilitation could significantly increase exercise capacity, physical activity function, and health-related quality of life (HRQoL) (all p < 0.05). The GRADE results showed low to very low certainty of evidence levels.

CONCLUSION

NMES could improve exercise capacity and reduce the perceived sensation of dyspnea during exercise and is recommended as an effective adjuvant training modality in the rehabilitation for moderate to severe COPD patients.

Neuromuscular electrical stimulation for physical function maintenance during hematopoietic stem cell transplantation: Study protocol

Hematopoietic stem cell transplantation is a common life-saving treatment for hematologic malignancies, though can lead to long-term functional impairment, fatigue, muscle atrophy, with decreased quality of life. Although traditional exercise has helped reduce these effects, it is inconsistently recommended and infrequently maintained, and most patients remain sedentary during and after treatment. There is need for alternative rehabilitation strategies, like neuromuscular electrical stimulation, that may be more amenable to the capabilities of hematopoietic stem cell transplant recipients. Patients receiving autologous HCT are being enroled in a randomized controlled trial with 1:1 (neuromuscular electrical stimulation:sham) design stratified by diagnosis and sex. Physical function, body composition, quality of life, and fatigue are assessed prior to hematopoietic stem cell transplant (prior to initiating preparatory treatment) and 24±5 days post hematopoietic stem cell transplant (Follow-up 1); physical function and quality of life are also assessed 6-months post hematopoietic stem cell transplant (Follow-up 2). The primary outcome is between-group difference in the 6-minute walk test change scores (Follow-up 1-Pre-transplant; final enrolment goal N = 23/group). We hypothesize that 1) neuromuscular electrical stimulation will attenuate hematopoietic stem cell transplant-induced adverse effects on physical function, muscle mass, quality of life, and fatigue compared to sham at Follow-up 1, and 2) Pre-transplant physical function will significantly predict fatigue and quality of life at Follow-up 2. We will also describe feasibility and acceptability of neuromuscular electrical stimulation during hematopoietic stem cell transplant. This proposal will improve rehabilitative patient care and quality of life by determining efficacy and feasibility of a currently underutilized therapeutic strategy aimed at maintaining daily function and reducing the impact of a potent and widely used cancer treatment. This trial is registered with clinicaltrials.gov (NCT04364256).

Differential changes in blood flow and oxygen utilization in active muscles between voluntary exercise and electrical muscle stimulation in young adults

The physiological effects on blood flow and oxygen utilization in active muscles during and after involuntary contraction triggered by electrical muscle stimulation (EMS) remain unclear, particularly compared with those elicited by voluntary (VOL) contractions. Therefore, we used diffuse correlation and near-infrared spectroscopy (DCS-NIRS) to compare changes in local muscle blood flow and oxygen consumption during and after these two types of muscle contractions in humans. Overall, 24 healthy young adults participated in the study, and data were successfully obtained from 17 of them. Intermittent (2-s contraction, 2-s relaxation) isometric ankle dorsiflexion with a target tension of 20% of maximal VOL contraction was performed by EMS or VOL for 2 min, followed by a 6-min recovery period. DCS-NIRS probes were placed on the tibialis anterior muscle, and relative changes in local tissue blood flow index (rBFI), oxygen extraction fraction (rOEF), and metabolic rate of oxygen (rMRO2) were continuously derived. EMS induced more significant increases in rOEF and rMRO2 than VOL exercise but a comparable increase in rBFI. After EMS, rBFI and rMRO2 decreased more slowly than after VOL and remained significantly higher until the end of the recovery period. We concluded that EMS augments oxygen consumption in contracting muscles by enhancing oxygen extraction while increasing oxygen delivery at a rate similar to the VOL exercise. Under the conditions examined in this study, EMS demonstrated a more pronounced and/or prolonged enhancement in local muscle perfusion and aerobic metabolism compared with VOL exercise in healthy participants.NEW & NOTEWORTHY This is the first study to visualize continuous changes in blood flow and oxygen utilization within contracted muscles during and after electrical muscle stimulation (EMS) using combined diffuse correlation and near-infrared spectroscopy. We found that initiating EMS increases blood flow at a rate comparable to that during voluntary (VOL) exercise but enhances oxygen extraction, resulting in higher oxygen consumption. Furthermore, EMS increased postexercise muscle perfusion and oxygen consumption compared with that after VOL exercise.

Qualitative interviews of patients with COPD and muscle weakness enrolled in a clinical trial evaluating a new anabolic treatment: patient perspectives of disease experience, trial participation and outcome assessments

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and muscle weakness can cause impaired physical function, significantly impacting patients' health-related quality of life (HRQoL). Loss of muscle strength is usually assessed through clinical and performance outcome (PerfO) assessments, which consists of tasks performed in a standardized manner, providing evidence of a patient's functional ability. However, evidence documenting the patient experience of COPD and muscle weakness is limited.

METHODS

This two-stage qualitative study used semi-structured interviews in patients aged 45-80 years with COPD (post-bronchodilator forced expiratory volume in 1s [FEV1]/forced vital capacity ratio < 0.70, and FEV1% predicted of 30-80%) and muscle weakness. In Stage 1, 30-minute concept elicitation interviews were conducted with participants recruited across three US sites to explore impacts on physical functioning and activities of daily living. In Stage 2, interviews were performed with participants exiting a Phase IIa trial investigating the efficacy of a selective androgen receptor modulator (GSK2881078) on leg strength, whereby PerfOs were used to evaluate strength and physical functioning endpoints. These participants completed either 60-minute in-depth (n = 32) or 15-minute confirmatory (n = 35) interviews exploring trial experience, completion of outcome measures, disease experience and treatment satisfaction.

RESULTS

In Stage 1 (n = 20), most participants described their muscles as weak (83.3%). Difficulties with walking (100%) and lifting heavy objects (90%) were reported. In Stage 2, 60-minute interviews, all participants (n = 32) reported a positive trial experience. Most participants reported that the home exercise program was easy to fit into daily life (77.8%), the PROactive daily diary was easy to complete (100%) and wearable sensors were easy to use (65.6%). However, technical issues were reported (71%), and few participants (19.4%) found physical assessments easy to complete. Improvements in muscle strength and functional limitations were reported by most participants. The shorter 15-minute confirmatory interviews (n = 35) supported the in-depth interview results.

CONCLUSION

The qualitative interviews generated in-depth evidence of key concepts relevant to patients with COPD and muscle weakness and support the assessments of patient strength and physical function as outcome measures in this population in future studies.

TRIAL NUMBER

GSK Stage 1: 206869; Stage 2: 200182, NCT03359473; Registered December 2, 2017, https://clinicaltrials.gov/ct2/show/NCT03359473 .

Exercise training initiated early during hospitalisation in individuals with chronic obstructive pulmonary disease is safe and improves exercise capacity and physical function at hospital discharge: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Earlier reviews of exercise in people during exacerbation of chronic obstructive pulmonary disease (COPD) included studies where exercise training was initiated late during hospital admission or shortly following hospital discharge. Our question was: in adults hospitalised with an exacerbation of COPD, does initiating exercise training early during an admission versus not initiating exercise training during admission, change outcomes measured at discharge?

METHODS

Systematic review and meta-analysis. Database searches of PubMed, the Cochrane Library, PEDro and EMBASE conducted in December 2021 and updated in January 2024. Studies were included if they had at least one group that was prescribed exercise training within 48 h of hospital admission (experimental) and at least one group that received usual care which did not include prescribed exercise training (control). Outcomes included exercise capacity, physical function, adverse events and uptake of outpatient pulmonary rehabilitation programs.

RESULTS

Ten studies (423 participants; mean FEV1 ranging from 26 % to 50 % predicted) were included. At discharge, compared to the control group, the experimental group demonstrated better exercise capacity (standardised mean difference (SMD) 0.58, 95 % confidence interval (CI) 0.32 to 0.83; five studies, moderate effect, low certainty evidence) and physical function (SMD -0.54, 95 % CI -0.86 to -0.22; four studies, moderate effect, low certainty evidence). No observed serious adverse events were reported. None of the studies reported uptake of pulmonary rehabilitation following discharge.

CONCLUSION

In adults with an exacerbation of COPD, exercise training prescribed within 48 h of hospitalisation was safe and improved exercise capacity and physical function.

20 years of neuromuscular electrical stimulation in COPD

Although a lung disease, COPD is also associated with extrapulmonary manifestations including, among others, limb muscle dysfunction. Limb muscle dysfunction is a key systemic consequence of COPD that impacts patients' physical activity, exercise tolerance, quality of life and survival. Deconditioning is the main mechanism underlying the development of limb muscle dysfunction in COPD, which can be partially improved with exercise. However, some patients may not be able to tolerate exercise because of incapacitating breathlessness or unwillingness to undertake whole-body exercise. Alternative training modalities that do not give rise to dyspnoea, such as neuromuscular electrical stimulation (NMES), are urged. Over the past 20 years, NMES in COPD has presented conflicting conclusions in meta-analysis. In this review, we try to understand the reason for this result by analysing possible biases and factors that brought conflicting conclusions. We discuss the population (the intervention group, but also the control group), the outcome measures, the frequency of stimulation, the rehabilitation protocol (i.e. NMES alone versus standard care/rehabilitation or NMES plus conventional exercise training versus conventional exercise training alone or NMES versus sham treatment) and the trial design. The main reason for this discrepancy is the lack of dedicated guidelines for NMES. Further research is urged to determine the optimal parameters for an NMES programme. Despite this, NMES appears to be an effective means of enhancing quadriceps strength and exercise capacity in COPD with the potential to break the vicious circle induced by the disease and COPD patients' lifestyle.

Efficacy of interventions to alter measures of fat-free mass in people with COPD: a systematic review and meta-analysis

Introduction

Low fat-free mass (FFM) is linked to poor health outcomes in COPD, including impaired exercise tolerance and premature death. The aim of this systematic review was to synthesise evidence on the effectiveness of interventions for increasing FFM in COPD.

Methods

Searches of electronic databases (MEDLINE, Cochrane Library, Embase, Web of Science, Scopus) and trial registers (ClinicalTrials.gov) were undertaken from inception to August 2022 for randomised studies of interventions assessing measures of FFM in COPD. The primary outcome was change in FFM (including derivatives). Secondary outcomes were adverse events, compliance and attrition.

Results

99 studies (n=5138 people with COPD) of 11 intervention components, used alone or in combination, were included. Exercise training increased mid-thigh cross-sectional area (k=3, standardised mean difference (SMD) 1.04, 95% CI 0.02-2.06; p=0.04), but not FFM (k=4, SMD 0.03, 95% CI -0.18-0.24; p=0.75). Nutritional supplementation significantly increased FFM index (k=11, SMD 0.31, 95% CI 0.13-0.50; p<0.001), but not FFM (k=19, SMD 0.16, 95% CI -0.06-0.39; p=0.16). Combined exercise training and nutritional supplementation increased measures related to FFM in 67% of studies. Anabolic steroids increased FFM (k=4, SMD 0.98, 95% CI 0.24-1.72; p=0.009). Neuromuscular electrical stimulation increased measures related to FFM in 50% of studies. No interventions were more at risk of serious adverse events, low compliance or attrition.

Discussion

Exercise training and nutritional supplementation were not effective in isolation to increase FFM, but were for localised muscle and index measures, respectively. Combined, exercise and nutritional supplementation shows promise as a strategy to increase FFM in COPD. Anabolic steroids are efficacious for increasing FFM in COPD.

Rehabilitation for People with Respiratory Disease and Frailty: An Official American Thoracic Society Workshop Report

People with respiratory disease have increased risk of developing frailty, which is associated with worse health outcomes. There is growing evidence of the role of rehabilitation in managing frailty in people with respiratory disease. However, several challenges remain regarding optimal methods of identifying frailty and delivering rehabilitation for this population. The aims of this American Thoracic Society workshop were to outline key definitions and concepts around rehabilitation for people with respiratory disease and frailty, synthesize available evidence, and explore how programs may be adapted to align to the needs and experiences of this population. Across two half-day virtual workshops, 20 professionals from diverse disciplines, professions, and countries discussed key developments and identified opportunities for future research, with additional input via online correspondence. Participants highlighted a "frailty rehabilitation paradox" whereby pulmonary rehabilitation can effectively reduce frailty, but programs are challenging for some individuals with frailty to complete. Frailty should not limit access to rehabilitation; instead, the identification of frailty should prompt comprehensive assessment and tailored support, including onward referral for additional specialist input. Exercise prescriptions that explicitly consider symptom burden and comorbidities, integration of additional geriatric or palliative care expertise, and/or preemptive planning for disruptions to participation may support engagement and outcomes. To identify and measure frailty in people with respiratory disease, tools should be selected on the basis of sensitivity, specificity, responsiveness, and feasibility for their intended purpose. Research is required to expand understanding beyond the physical dimensions of frailty and to explore the merits and limitations of telerehabilitation or home-based pulmonary rehabilitation for people with chronic respiratory disease and frailty.

Selective androgen receptor modulation for muscle weakness in chronic obstructive pulmonary disease: a randomised control trial

BACKGROUND

Selective androgen receptor modulators (SARMs) increase muscle mass via the androgen receptor. This phase 2A trial investigated the effects of a SARM, GSK2881078, in conjunction with exercise, on leg strength in patients with chronic obstructive pulmonary disease (COPD) and impaired physical function.

METHODS

47 postmenopausal women and 50 men with COPD (forced expiratory volume in 1 s 30%-65% predicted; short physical performance battery score: 3-11) were enrolled into a randomised double-blind, placebo control trial. Patients were randomised 1:1 to once daily placebo or oral GSK2881078 (females: 1.0 mg; males: 2.0 mg) for 13 weeks with a concurrent home-exercise programme, involving strength training and physical activity. Primary endpoints were change from baseline in leg strength at 90 days (one-repetition maximum; absolute (kg) and relative (% change)) and multiple safety outcomes. Secondary endpoints included lean body mass, physical function and patient-reported outcomes.

RESULTS

GSK2881078 increased leg strength in men. The difference in adjusted mean change from baseline and adjusted mean percentage change from baseline between treatment and placebo were: for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0), respectively; for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6), respectively. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in high-density lipoprotein-cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

CONCLUSIONS

GSK2881078 was well tolerated and short-term treatment increased leg strength, when expressed as per cent predicted, in men with COPD more than physical training alone.

TRIAL REGISTRATION NUMBER

NCT03359473.

Current pharmacological strategies for symptomatic reduction of persistent breathlessness - a literature review

INTRODUCTION

Persistent breathlessness is a debilitating symptom that is prevalent in the community, particularly in people with chronic and life-limiting illnesses. Treatment includes different steps, including pharmacological treatment aiming to improve the symptom and optimize people's wellbeing.

AREAS COVERED

PubMed and Google Scholar were screened using 'chronic breathlessness' OR 'persistent breathlessness,' AND 'pharmacological treatment,' OR 'opioids.' This review focuses on pharmacological treatments to reduce persistent breathlessness and discusses possible mechanisms involved in the process of breathlessness reduction through pharmacotherapy. Research gaps in the field of persistent breathlessness research are outlined, and future research directions are suggested.

EXPERT OPINION

Regular, low-dose (≤30 mg/day), sustained-release morphine is recommended as the first-line pharmacological treatment for persistent breathlessness. Inter-individual variation in response needs to be investigated in future studies in order to optimize clinical outcomes. This includes 1) better understanding the centrally mediated mechanisms associated with persisting breathlessness and response to pharmacological therapies, 2) understanding benefit from the perspective of people experiencing persistent breathlessness, small and meaningful gains in physical activity.

Stimulation of both inspiratory and expiratory muscles versus diaphragm-only paradigm for rehabilitation in severe chronic obstructive pulmonary disease patients: a randomized controlled pilot study

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a progressive lung disease, might improve with neuromuscular electrical stimulation. No trials on inspiratory plus expiratory neuromuscular electrical stimulation have been conducted yet.

AIM

The aim of this study was to evaluate the safety and effectiveness of inspiratory plus expiratory neuromuscular electrical stimulation in subjects with severe COPD.

DESIGN

This was a multicenter, prospective, randomized controlled trial.

SETTING

The subjects were outpatients enrolled from Beijing Chao-Yang Hospital affiliated with Capital Medical University, Tianjin Chest Hospital, and the First Hospital of Hebei Medical University.

POPULATION

Subjects had stable COPD with severe respiratory impairment.

METHODS

Using a computer statistical software, 120 stable subjects were randomly allocated (1:1) to receive inspiratory plus expiratory neuromuscular electrical stimulation (study group) and diaphragm pacing (control group). Demographic and clinical data were collected before, and after 2, and 4 weeks of the trial. The intention-to-treat analysis was conducted. The primary outcome was to analyze the changes in functional exercise capacity, estimated as six-minute walk distance (6MWD), following electrical stimulation for 4 weeks. The secondary outcomes were changes in modified Medical Research Council score, forced expiratory volume in 1 second (FEV<inf>1</inf>), FEV<inf>1</inf>% predicted, and FEV<inf>1</inf> ratio forced vital capacity (FEV<inf>1</inf>/FVC) following electrical stimulation for 4 weeks.

RESULTS

The change in 6MWD was greater in the study group (65.53±39.45 m) than in the control group (26.66±32.65 m). The mean between-group difference at the fourth week was 29.07 m (95% confidence interval, 16.098-42.035; P<0.001). There were no significant between-group differences in the secondary outcomes after 4 weeks of electrical stimulation. For GOLD-4 COPD subjects, FEV<inf>1</inf> and FEV<inf>1</inf>/FVC improved in the study group (P<0.05). No electrical stimulation-related serious adverse events were observed in either group.

CONCLUSIONS

6MWD were increased significantly, without adverse events, after four weeks of treatment of inspiratory plus expiratory neuromuscular electrical stimulation in stable patients with severe COPD, suggesting that this protocol benefits COPD rehabilitation.

CLINICAL REHABILITATION IMPACT

The results of this study suggest that the simultaneous use of inspiratory plus expiratory neuromuscular electrical stimulation as an adjunct therapy may improve the functional exercise capacity of severe stable COPD subjects.

Effect of Pulmonary Rehabilitation on Postoperative Clinical Status in Patients with Lung Cancer and Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Pulmonary rehabilitation (PR) has a curative effect in patients undergoing pneumonectomy for lung cancer. Nevertheless, the contribution of PR to the clinical status of patients with chronic obstructive pulmonary disease (COPD) undergoing lung resection has not been adequately elucidated. The aim of this systematic review of randomized and nonrandomized controlled trials was to appraise the impact of PR compared to conventional treatment based on postoperative clinical status in patients with lung cancer and COPD. Literature in English from PubMed, Cochrane Library, Science Citation Index, and Embase databases and in Chinese from the Chinese National Knowledge Infrastructure and the WANFANG Database was retrieved from inception to November 2021, employing the keywords "Pulmonary Neoplasms," "Chronic Obstructive Pulmonary Diseases," "Physical Therapy Modalities," and "pulmonary rehabilitation." Only studies that reported PR results were included. This review was registered in the International Prospective Register of Systematic Reviews (number: CRD42021224343). A total of nine controlled trials with 651 patients were included. Postoperative pulmonary complications (PPCs) were the primary outcome measure. PR decreased the risk of complications after surgery compared to regular treatment (odds ratio (OR) 0.21, 95% confidence interval (CI) 0.12-0.37, P < 0.01). PR reduced the risk of pneumonia after surgery compared to regular treatment (OR 0.36, 95% CI 0.15-0.86, P=0.02). There was a significant difference in the postoperative length of stay (mean difference -2.13 days, 95% CI -2.65 to -1.61 days, P < 0.05). PR was an effective intervention that decreased PPCs in patients suffering from lung cancer and COPD. However, due to the limitations of the available data, the results should be interpreted with caution.

Region-Dependent Increase of Cerebral Blood Flow During Electrically Induced Contraction of the Hindlimbs in Rats

Elevation of cerebral blood flow (CBF) may contribute to the cerebral benefits of the regular practice of physical exercise. Surprisingly, while electrically induced contraction of a large muscular mass is a potential substitute for physical exercise to improve cognition, its effect on CBF remains to be investigated. Therefore, the present study investigated CBF in the cortical area representing the hindlimb, the hippocampus and the prefrontal cortex in the same anesthetized rats subjected to either acute (30 min) or chronic (30 min for 7 days) electrically induced bilateral hindlimb contraction. While CBF in the cortical area representing the hindlimb was assessed from both laser doppler flowmetry (LDF_CBF) and changes in p-eNOS^Ser1177 levels (p-eNOS_CBF), CBF was evaluated only from changes in p-eNOS^Ser1177 levels in the hippocampus and the prefrontal cortex. The contribution of increased cardiac output and increased neuronal activity to CBF changes were examined. Stimulation was associated with tachycardia and no change in arterial blood pressure. It increased LDF_CBF with a time- and intensity-dependent manner as well as p-eNOS_CBF in the area representing the hindlimb. By contrast, p-eNOS_CBF was unchanged in the two other regions. The augmentation of LDF_CBF was partially reduced by atenolol (a ß1 receptor antagonist) and not reproduced by the administration of dobutamine (a ß1 receptor agonist). Levels of c-fos as a marker of neuronal activation selectively increased in the area representing the hindlimb. In conclusion, electrically induced bilateral hindlimb contraction selectively increased CBF in the cortical area representing the stimulated muscles as a result of neuronal hyperactivity and increased cardiac output. The absence of CBF changes in cognition-related brain regions does not support flow-dependent neuroplasticity in the pro-cognitive effect of electrically induced contraction of a large muscular mass.

Diaphragm Dysfunction and Rehabilitation Strategy in Patients With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) affects the whole body and causes many extrapulmonary adverse effects, amongst which diaphragm dysfunction is one of the prominent manifestations. Diaphragm dysfunction in patients with COPD is manifested as structural changes, such as diaphragm atrophy, single-fibre dysfunction, sarcomere injury and fibre type transformation, and functional changes such as muscle strength decline, endurance change, diaphragm fatigue, decreased diaphragm mobility, etc. Diaphragm dysfunction directly affects the respiratory efficiency of patients and is one of the important pathological mechanisms leading to progressive exacerbation of COPD and respiratory failure, which is closely related to disease mortality. At present, the possible mechanisms of diaphragm dysfunction in patients with COPD include systemic inflammation, oxidative stress, hyperinflation, chronic hypoxia and malnutrition. However, the specific mechanism of diaphragm dysfunction in COPD is still unclear, which, to some extent, increases the difficulty of treatment and rehabilitation. Therefore, on the basis of the review of changes in the structure and function of COPD diaphragm, the potential mechanism of diaphragm dysfunction in COPD was discussed, the current effective rehabilitation methods were also summarised in this paper. In order to provide direction reference and new ideas for the mechanism research and rehabilitation treatment of diaphragm dysfunction in COPD.

Effects of neuromuscular electrical stimulation on exercise capacity, muscle strength and quality of life in COPD patients: A Systematic Review with Meta-Analysis

OBJECTIVE

To determine the effects of neuromuscular electrical stimulation on disabilities and activity limitation of individuals affected by chronic obstructive pulmonary disease.

DATA SOURCES

MEDLINE, PEDro database, Cochrane Controlled Trials Register, and SciELO, were searched from inception until October 2021.

REVIEW METHODS

Inclusion criteria were patients with COPD, randomized controlled trials comparing neuromuscular electrical stimulation alone or combined conventional pulmonary rehabilitation and neuromuscular electrical stimulation versus control or sham or pulmonary rehabilitation in disabilities and activity limitation in COPD. There were no mandatory language or publication date restrictions. Two reviewers selected studies independently. Weighted mean differences and 95% confidence intervals were calculated.

RESULTS

32 studies met the study criteria, including 1.269 participants. Neuromuscular electrical stimulation improved exercise capacity (MD 1.10, 95% CI: 0.33, 1.86, N = 147), and muscle strength (0.53, 95% CI: 0.20, 0.87, N = 147) compared to sham group. Combined neuromuscular electrical stimulation and conventional rehabilitation improved exercise capacity (MD 34.28 meters, 95% CI: 6.84, 61.73, N = 262) compared to conventional rehabilitation alone. No adverse events were reported.

CONCLUSIONS

Neuromuscular electrical stimulation resulted in small improvement in disabilities and activity limitation (below the MCID) in COPD. Thus, the inclusion of neuromuscular electrical stimulation in rehabilitation programs must consider the cost Because of inadequate methodological conduction and reporting of methods, some studies were of low quality.

Update on the Etiology, Assessment, and Management of COPD Cachexia: Considerations for the Clinician

Cachexia is a commonly observed but frequently neglected extra-pulmonary manifestation in patients with chronic obstructive pulmonary disease (COPD). Cachexia is a multifactorial syndrome characterized by severe loss of body weight, muscle, and fat, as well as increased protein catabolism. COPD cachexia places a high burden on patients (eg, increased mortality risk and disease burden, reduced exercise capacity and quality of life) and the healthcare system (eg, increased number, length, and cost of hospitalizations). The etiology of COPD cachexia involves a complex interplay of non-modifiable and modifiable factors (eg, smoking, hypoxemia, hypercapnia, physical inactivity, energy imbalance, and exacerbations). Addressing these modifiable factors is needed to prevent and treat COPD cachexia. Oral nutritional supplementation combined with exercise training should be the primary multimodal treatment approach. Adding a pharmacological agent might be considered in some, but not all, patients with COPD cachexia. Clinicians and researchers should use longitudinal measures (eg, weight loss, muscle mass loss) instead of cross-sectional measures (eg, low body mass index or fat-free mass index) where possible to evaluate patients with COPD cachexia. Lastly, in future research, more detailed phenotyping of cachectic patients to enable a better comparison of included patients between studies, prospective longitudinal studies, and more focus on the impact of exacerbations and the role of biomarkers in COPD cachexia, are highly recommended.

Early Pulmonary Rehabilitation with Neuromuscular Electrical Stimulation in a Patient with Acute Exacerbation of Rheumatoid Arthritis-associated Interstitial Lung Disease: A Case Report

INTRODUCTION

Early implementation of neuromuscular electrical stimulation (NMES) has been reported to prevent muscle atrophy and physical functional decline in patients requiring mechanical ventilation. However, its effect in patients with acute exacerbation of interstitial lung disease (ILD) remains unclear. We herein report our experience using the NMES combined with mobilization in a patient with an acute exacerbation of rheumatoid arthritis-associated ILD (RA-ILD) requiring mechanical ventilation.

CASE PRESENTATION

A 74-year-old man was admitted to the intensive care unit (ICU) and put on mechanical ventilation due to severe acute exacerbation of RA-ILD. Early mobilization and the NMES using a belt electrode skeletal muscle electrical stimulation system were started on day 7 of hospitalization (day 2 of ICU admission). The NMES duration was 20 min, performed once daily. The patient could perform mobility exercises on day 8 and could walk on day 16. We assessed his rectus femoris and quadriceps muscle thicknesses using ultrasound imaging, and found decreases of 4.5% and 8.4%, respectively, by day 14. On day 27, he could independently visit the lavatory, and the NMES was discontinued. He was instructed to start long-term oxygen therapy on day 49 and was discharged on day 63. His 6-minute walk distance was 308 m and his muscle thickness recovered to levels comparable to those at the initial evaluation at the time of discharge.

CONCLUSION

Combining the NMES and mobilization started in the early phase and continued after ICU discharge was safe and effective in a patient with a severe acute exacerbation of RA-ILD.

A voluntary activation deficit in m. abductor hallucis exists in asymptomatic feet

M. abductor hallucis (AbH) is the strongest intrinsic foot muscle and its dysfunction underlies various foot disorders. Attempts to strengthen the muscle by voluntary exercises are constrained by its complex morphology and oblique mechanical action, which leads to an inability even in asymptomatic individuals to fully activate AbH. This study investigated the extent and magnitude of this inability whilst also providing preliminary evidence for the virtue of targeted sub-maximum neuromuscular electrical stimulation (NMES) as a countermeasure for an AbH activation deficit. The voluntary activation ratio (VAR) was assessed via the twitch interpolation technique in the left AbH of 13 healthy participants during maximum voluntary 1st metatarsophalangeal joint flexion-abduction contractions (MVC). Participants were grouped ("able" or "unable") based on their ability to fully activate AbH (VAR ≥ 0.9). 7 s-NMES trains (20 Hz) were then delivered to AbH with current intensity increasing from 150% to 300% motor threshold (MT) in 25% increments. Perceived comfort was recorded (10 cm-visual analogue scale; VAS). Only 3 participants were able to activate AbH to its full capacity (able, mean (range) VAR: 0.93 (0.91-0.95), n = 3; unable: 0.69 (0.36-0.83), n = 10). However, the maximum absolute forces produced during the graded sub-maximum direct-muscle NMES protocol were comparable between groups implying that the peripheral contractility of AbH is intact irrespective of the inability of individuals to voluntary activate AbH to its full capacity. These findings demonstrate that direct-muscle NMES overcomes the prevailing inability for high voluntary AbH activation and therefore offers the potential to strengthen the healthy foot and restore function in the pathological foot.

Effects of different electrical stimulation currents and phase durations on submaximal and maximum torque, efficiency, and discomfort: a randomized crossover trial

BACKGROUND

Neuromuscular electrical stimulation (NMES) is an important therapeutic tool for rehabilitation. However, best stimulation parameters remain to be determined.

OBJECTIVE

To determine the influence of different electrical stimulation currents and phase durations on torque, efficiency, and discomfort.

METHODS

Using a cross-over design, kHz frequency alternating currents (KFAC) and pulsed currents (PC) with narrow (200 µs) or wide (500 µs) phase durations were randomly applied on knee extensor muscles of healthy participants with a minimum of seven days between sessions. The NMES-evoked torque, NMES-efficiency, and discomfort (visual 0-10 cm analogue scale) were measured for each stimulation intensity increments (10 mA). Statistics were conducted using a three-way analysis of variances (phase duration x current x intensity), followed by Tukey post-hoc.

RESULTS

Twenty-four males (age 22.3 ± 3.5years) were included. No effect of NMES current was observed for torque, efficiency, and discomfort. For wide phase durations (500 µs), torque significantly increased for all stimulation intensities. For narrow phase durations (200 µs) evoked torque significantly increased only after 40% of maximal stimulation intensity. Phase durations of 500 µs produced greater torque than 200 µs. Discomfort was greater with 500 µs when compared to 200 µs. Submaximal relative torque, for example 40% of maximum voluntary contraction (MVC), was obtained with ∼ 60% and ∼ 80% of the maximal current intensity for 500 µs and 200 µs, respectively.

CONCLUSION

KFAC and PC current applied with the same phase duration induced similar relative submaximal and maximum evoked-torque, efficiency, and perceived discomfort. However, currents with 500 µs induced higher evoked-torque, current efficiency, and perceived discomfort.

Does increasing the number of channels during neuromuscular electrical stimulation reduce fatigability and produce larger contractions with less discomfort?

PURPOSE

Neuromuscular electrical stimulation (NMES) is often delivered at frequencies that recruit motor units (MUs) at unphysiologically high rates, leading to contraction fatigability. Rotating NMES pulses between multiple electrodes recruits subpopulations of MUs from each site, reducing MU firing rates and fatigability. This study was designed to determine whether rotating pulses between an increasing number of stimulation channels (cathodes) reduces contraction fatigability and increases the ability to generate torque during NMES. A secondary outcome was perceived discomfort.

METHODS

Fifteen neurologically intact volunteers completed four sessions. NMES was delivered over the quadriceps through 1 (NMES₁), 2 (NMES₂), 4 (NMES₄) or 8 (NMES₈) channels. Fatigability was assessed over 100 contractions (1-s on/1-s off) at an initial contraction amplitude that was 20% of a maximal voluntary contraction. Torque-frequency relationships were characterized over six frequencies from 20 to 120 Hz.

RESULTS

NMES₄ and NMES₈ resulted in less decline in peak torque (42 and 41%) over the 100 contractions than NMES₁ and NMES₂ (53 and 50% decline). Increasing frequency from 20 to 120 Hz increased torque by 7, 13, 21 and 24% MVC, for NMES₁, NMES₂, NMES₄ and NMES₈, respectively. Perceived discomfort was highest during NMES₈.

CONCLUSION

NMES₄ and NMES₈ reduced contraction fatigability and generated larger contractions across a range of frequencies than NMES₁ and NMES₂. NMES₈ produced the most discomfort, likely due to small electrodes and high current density. During NMES, more is not better and rotating pulses between four channels may be optimal to reduce contraction fatigability and produce larger contractions with minimal discomfort compared to conventional NMES configurations.

[Pulmonary Rehabilitation in Patients with Chronic Obstructive Airway Diseases]

Pulmonary rehabilitation of asthma and COPD patients can improve their physical performance and quality of life, maintain participation in social and professional life and actively promote self-help. In addition, the resources for acute medical treatment can be spared. In case of COPD, rehabilitation directly after exacerbation can also improve the poor survival prognosis and reduce the risk of emergency hospital readmission. Therefore, pulmonary rehabilitation is an essential component of evidence-based long-term management of both bronchial asthma and, in particular, COPD. In the German healthcare system, however, pneumological rehabilitation is offered only for a small fraction of patients. Despite a very good evidence of pulmonary rehabilitation, especially in COPD patients, their share in all rehabilitation services is remarkably low. It does not even amount to 3 % of all medical rehabilitation measures approved by the German Pension Insurance.

Muscle stimulation in advanced idiopathic pulmonary fibrosis: a randomised placebo-controlled feasibility study

OBJECTIVES

To assess the acceptability of neuromuscular electrical stimulation (NMES) of the quadriceps muscles in people with idiopathic pulmonary fibrosis (IPF) and to identify whether a future definitive trial is feasible.

DESIGN

A randomised, parallel, two-group, participant and assessor-blinded, placebo-controlled feasibility trial with embedded qualitative interviews.

SETTING

Outpatient department, Royal Brompton and Harefield Hospitals.

PARTICIPANTS

Twenty-two people with IPF: median (25th, 75th centiles) age 76 (74, 82) years, forced vital capacity 62 (50, 75) % predicted, 6 min walk test distance 289 (149, 360) m.

INTERVENTIONS

Usual care (home-based exercise, weekly telephone support, breathlessness management leaflet) with either placebo or active NMES for 6 weeks, with follow-up at 6 and 12 weeks.

PRIMARY OUTCOME MEASURES

Feasibility of recruitment and retention, treatment uptake and adherence, outcome assessments, participant and outcome assessor blinding and adverse events related to interventions.

SECONDARY OUTCOME MEASURES

Outcome measures with potential to be primary or secondary outcomes in a definitive clinical trial. In addition, purposively sampled participants were interviewed to capture their experiences and acceptability of the trial.

RESULTS

Out of 364 people screened, 23 were recruited: 11 were allocated to each group and one was withdrawn prior to randomisation. Compared with the control group, a greater proportion of the intervention group completed the intervention, remained in the trial blinded to group allocation and experienced intervention-related adverse events. Assessor blinding was maintained. The secondary outcome measures were feasible with most missing data associated with the accelerometer. Small participant numbers precluded identification of an outcome measure suitable for a definitive trial. Qualitative findings demonstrated that trial process and active NMES were acceptable but there were concerns about the credibility of placebo NMES.

CONCLUSIONS

Primarily owing to recruitment difficulties, a definitive trial using the current protocol to evaluate NMES in people with IPF is not feasible.

TRIAL REGISTRATION NUMBER

NCT03499275.

[Rehabilitation in pneumology]

Die pneumologische Rehabilitation (PR) ist eine evidenzbasierte interdisziplinäre Behandlung für Patienten mit chronischen Erkrankungen der Atmungsorgane. Die Indikation für ihre Beantragung ist bei entsprechender Rehabilitationsfähigkeit, -bedürftigkeit und günstigen -prognose gegeben. Ziele einer PR sind die Reduktion der Symptome sowie die Steigerung der Lebensqualität und körperlichen Belastbarkeit. Die Effektivität ist für COPD-Patienten (COPD: chronisch obstruktive Lungenerkrankung) mit dem höchsten und für Nicht-COPD-Patienten mit zunehmend gutem Evidenzgrad durch randomisiert kontrollierte Studien und Metaanalysen gesichert. Die Therapieinhalte einer PR werden durch ein multidisziplinäres Behandlungsteam individuell an die Bedürfnisse der Patienten angepasst. Um den Rehabilitationserfolg nachhaltig zu gestalten, besteht die Möglichkeit, an ambulanten Nachsorgeprogrammen (z. B. Lungensport) teilzunehmen sowie digitale Technologien als unterstützende Maßnahme einzusetzen.

Effects of neuromuscular electrical stimulation on exercise capacity and quality of life in COPD patients: a systematic review and meta-analysis

Neuromuscular electrical stimulation (NMES) has been shown to produce benefits in the muscle function of chronic obstructive pulmonary disease (COPD) patients. The definite effectiveness of NMES, applied in isolation or concurrently with conventional pulmonary rehabilitation (PR) or exercise training, remains unclear. This review was to determine the effects of NMES on exercise capacity, functional performance, symptoms, and health-related quality of life (HRQoL) in COPD patients. Electronic databases (PubMed, Embase, Web of Science, the Cochrane Library) were searched for relevant randomized controlled trials (RCTs). Two investigators independently screened the eligible studies up to February 2020 that used NMES as the intervention group. The outcome measures were 6-min walking distance (6MWD), peak rate of oxygen uptake (VO₂ peak), St George’s Respiratory Questionnaire (SGRQ), and symptoms of dyspnoea and fatigue. Data were extracted using a predefined table and papers were appraised using Downs and Black tool. We analyzed 13 RCTs with 447 COPD patients. In the analysis of 6MWD, pooled estimates showed a significant increase in the NMES group, compared with the control group (mean difference (MD) = 27.05, 95% confidence interval (CI): 8.46–45.63, P<0.001). There were also improvements in symptoms of dyspnea or leg fatigue, and reduction in London Chest Activity of Daily Living (LCADL) scores. No statistically significant difference was observed in VO₂ peak, peak power, and SGRQ. NMES could improve exercise capacity and reduce perceived sensation of dyspnea during exercise in patients with COPD, but not to be recommended as an effective alternative training modality in the rehabilitation of stable COPD patients.

Skeletal Muscle Damage Produced by Electrically Evoked Muscle Contractions

Understanding the physiological/mechanical mechanisms leading to skeletal muscle damage remains one of the challenges in muscle physiology. This review presents the functional, structural, and cellular consequences of electrically evoked submaximal isometric contractions that can elicit severe and localized skeletal muscle damage. Hypotheses related to underlying physiological and mechanical processes involved in severe and localized muscle damage also are discussed.

COPD phenotypes and machine learning cluster analysis: A systematic review and future research agenda

Chronic Obstructive Pulmonary Disease (COPD) is a highly heterogeneous condition projected to become the third leading cause of death worldwide by 2030. To better characterize this condition, clinicians have classified patients sharing certain symptomatic characteristics, such as symptom intensity and history of exacerbations, into distinct phenotypes. In recent years, the growing use of machine learning algorithms, and cluster analysis in particular, has promised to advance this classification through the integration of additional patient characteristics, including comorbidities, biomarkers, and genomic information. This combination would allow researchers to more reliably identify new COPD phenotypes, as well as better characterize existing ones, with the aim of improving diagnosis and developing novel treatments. Here, we systematically review the last decade of research progress, which uses cluster analysis to identify COPD phenotypes. Collectively, we provide a systematized account of the extant evidence, describe the strengths and weaknesses of the main methods used, identify gaps in the literature, and suggest recommendations for future research.

Interventions for promoting physical activity in people with chronic obstructive pulmonary disease (COPD)

BACKGROUND

Escalating awareness of the magnitude of the challenge posed by low levels of physical activity in people with chronic obstructive pulmonary disease (COPD) highlights the need for interventions to increase physical activity participation. The widely-accepted benefits of physical activity, coupled with the increasing availability of wearable monitoring devices to objectively measure participation, has led to a dramatic rise in the number and variety of studies that aimed to improve the physical activity of people with COPD. However, little was known about the relative efficacy of interventions tested so far.

OBJECTIVES

In people with COPD, which interventions are effective at improving objectively-assessed physical activity?

SEARCH METHODS

We identified trials from the Cochrane Airways Trials Register Register, which contains records identified from bibliographic databases including the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, AMED, and PsycINFO. We also searched PEDro, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform portal and the Australian New Zealand Clinical Trials Registry (from inception to June 2019). We checked reference lists of all primary studies and review articles for additional references, as well as respiratory journals and respiratory meeting abstracts, to identify relevant studies.

SELECTION CRITERIA

We included randomised controlled trials of interventions that used objective measures for the assessment of physical activity in people with COPD. Trials compared an intervention with no intervention or a sham/placebo intervention, an intervention in addition to another standard intervention common to both groups, or two different interventions.

DATA COLLECTION AND ANALYSIS

We used standard methods recommended by Cochrane. Subgroup analyses were possible for supervised compared to unsupervised pulmonary rehabilitation programmes in clinically-stable COPD for a range of physical activity outcomes. Secondary outcomes were health-related quality of life, exercise capacity, adverse events and adherence. Insufficient data were available to perform prespecified subgroup analyses by duration of intervention or disease severity. We undertook sensitivity analyses by removing studies that were at high or unclear risk of bias for the domains of blinding and incomplete outcome data.

MAIN RESULTS

We included 76 studies with 8018 participants. Most studies were funded by government bodies, although some were sponsored by equipment or drug manufacturers. Only 38 studies had physical activity as a primary outcome. A diverse range of interventions have been assessed, primarily in single studies, but improvements have not been systematically demonstrated following any particular interventions. Where improvements were demonstrated, results were confined to single studies, or data for maintained improvement were not provided. Step count was the most frequently reported outcome, but it was commonly assessed using devices with documented inaccuracy for this variable. Compared to no intervention, the mean difference (MD) in time in moderate- to vigorous-intensity physical activity (MVPA) following pulmonary rehabilitation was four minutes per day (95% confidence interval (CI) -2 to 9; 3 studies, 190 participants; low-certainty evidence). An improvement was demonstrated following high-intensity interval exercise training (6 minutes per day, 95% CI 4 to 8; 2 studies, 275 participants; moderate-certainty evidence). One study demonstrated an improvement following six months of physical activity counselling (MD 11 minutes per day, 95% CI 7 to 15; 1 study, 280 participants; moderate-certainty evidence), but we found mixed results for the addition of physical activity counselling to pulmonary rehabilitation. There was an improvement following three to four weeks of pharmacological treatment with long-acting muscarinic antagonist and long-acting beta2-agonist (LAMA/LABA) compared to placebo (MD 10 minutes per day, 95% CI 4 to 15; 2 studies, 423 participants; high-certainty evidence). These interventions also demonstrated improvements in other measures of physical activity. Other interventions included self-management strategies, nutritional supplementation, supplemental oxygen, endobronchial valve surgery, non-invasive ventilation, neuromuscular electrical stimulation and inspiratory muscle training.

AUTHORS' CONCLUSIONS

A diverse range of interventions have been assessed, primarily in single studies. Improvements in physical activity have not been systematically demonstrated following any particular intervention. There was limited evidence for improvement in physical activity with strategies including exercise training, physical activity counselling and pharmacological management. The optimal timing, components, duration and models for interventions are still unclear. Assessment of quality was limited by a lack of methodological detail. There was scant evidence for a continued effect over time following completion of interventions, a likely requirement for meaningful health benefits for people with COPD.

Design considerations for the development of neuromuscular electrical stimulation (NMES) exercise in cancer rehabilitation

Aim: The aim of this narrative review is to explore design considerations for effective neuromuscular electrical stimulation exercise prescription in cancer rehabilitation, with simultaneous consideration for fundamental principles of exercise training and the current state of the art in neuromuscular electrical stimulation technologies and application methodologies.Method: Narrative review.Results: First, we consider the key neuromuscular electrical stimulation exercise design considerations, with a focus on training objectives and individual training requirements and constraints for individuals with cancer. Here, we contend that concurrent, low and high frequency neuromuscular electrical stimulation exercise, individually prescribed and progressed may be optimal for enhancing physical function. Second, we review the appropriate literature to identify the most appropriate stimulation parameters (pulse frequency, intensity, duration and duty cycle) to deliver effective neuromuscular electrical stimulation in cancer rehabilitation.Conclusions: We propose an informed and innovative neuromuscular electrical stimulation exercise intervention design and provide practical information for clinicians and practitioners who may work with and implement neuromuscular electrical stimulation exercise in cancer.Implications for rehabilitationNeuromuscular electrical stimulation is an emerging technology in cancer rehabilitation to help provide an aerobic and muscle strengthening exercise stimulus.Neuromuscular electrical stimulation may help improve aerobic exercise capacity, muscle strength and augment quality of life.Current prescription in cancer lacks adherence to the fundamental principles of exercise training, which may negatively affect adherence.

Effects of neuromuscular electrical stimulation in patients with pulmonary arterial hypertension: a randomized controlled pilot study

BACKGROUND

Patients with pulmonary arterial hypertension (PAH) present impairments in muscle strength and exercise capacity. There is growing evidence about the benefits of neuromuscular electrical stimulation (NMES) in patients with respiratory diseases, except in patients with PAH. The aim of this study was to investigate the effects of NMES on muscle strength, and other physical and psychosocial variables in patients with PAH.

METHODS

Patients with PAH were randomly divided into two groups as NMES and control. The NMES was applied to the bilateral deltoid and quadriceps femoris muscles with 50 Hz for 3 days/week, 8 weeks for the NMES group. Muscle strength, muscle cross-sectional area and thickness, arterial stiffness, exercise capacity, functional mobility and balance, balance confidence, fatigue, physical activity, and quality of life were assessed at baseline and after 8 weeks by blinded assessors.

RESULTS

There was no significant difference in the demographic and clinical characteristics between the patient groups (p > 0.05). The improvements in muscle strength, muscle cross-sectional area and thickness, pulse wave velocity, exercise capacity, functional mobility and balance, balance confidence, fatigue, physical activity, and quality of life were significantly higher in the NMES group compared to the control group (p < 0.05).

CONCLUSIONS

This study suggests that NMES intervention is safe and effective for patients with PAH.

Electrical Stimulation of Muscle: Electrophysiology and Rehabilitation

The generation of action potentials in intramuscular motor and sensory axons in response to an imposed external current source can evoke muscle contractions and elicit widespread responses throughout the nervous system that impact sensorimotor function. The benefits experienced by individuals exposed to several weeks of treatment with electrical stimulation of muscle suggest that the underlying adaptations involve several physiological systems, but little is known about the specific changes elicited by such interventions.

Exercise Training Modalities for People with Chronic Obstructive Pulmonary Disease

Exercise training confers health benefits for people with chronic obstructive pulmonary disease (COPD). This article reviews the evidence for several exercise training modalities shown to be beneficial among individuals with COPD. These modalities include aerobic, resistance, nonlinear periodized, upper limb and balance training, as well as yoga, Tai Chi, inspiratory muscle training, whole body vibration training and neuromuscular electrical stimulation. The literature pertaining to each modality was critically reviewed, and information on the rationale, mechanism(s) of action (where known), benefits, and exercise prescription is described to facilitate easy implementation into clinical practice.

Efficacy of neuromuscular electric stimulation versus aerobic exercise on uraemic restless legs syndrome

Background

The prevalence of restless legs syndrome in haemodialysis patients is approximately ~30%, and it is significantly higher than in the general population. Restless legs syndrome is a sensory-motor disorder with negative effects on sleep and daytime activities that affect personal, family and occupational life. The overall impact of restless legs syndrome on quality of life is comparable to that of chronic and frustrating conditions such as depression and diabetes. The present study was conducted to compare the effect of neuromuscular electric stimulation with aerobic exercise on cases of uraemic restless legs syndrome.

Methods

A total of 60 chronic renal failure patients with uraemic restless legs syndrome aged 20 to 65 years participated in this study. Participants were allocated to receive neuromuscular electric stimulation or aerobic exercises. All participants were evaluated before the first session of treatment and after 3 months, at the end of the treatment. Normal and fast walk gait speed tests and the Five Times Sit-to-Stand Test and 60 second Sit-to-Stand Test were used to assess participants' physical status. The Restless Legs Syndrome Rating Scale was used to determine the level of restless legs syndrome severity.

Results

Neuromuscular electric stimulation resulted in significant improvements in all measures of physical performance and in Restless Legs Syndrome Rating Scale score when compared to baseline. Aerobic exercise produced significant improvements in all tests. At the end of the study, aerobic exercise had greater responses than neuromuscular electric stimulation in all parameters measured except the Five Times Sit-to-Stand Test.

Conclusions

Neuromuscular electrical stimulation may be used as an alternative to aerobic exercise to improve physical performance in cases of less severe restless legs syndrome in those unable or unwilling to participate in physical training.

Effects of a comprehensive, inpatient pulmonary rehabilitation programme in a cachectic patient with very severe COPD and chronic respiratory failure

A cachectic patient with very severe COPD and chronic respiratory failure may benefit from comprehensive and personalised pulmonary rehabilitation including neuromuscular electrical stimulation, noninvasive ventilation and anabolic steroids http://bit.ly/31Ss7WZ.

Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease. What We Know and Can Do for Our Patients

Skeletal muscle dysfunction occurs in patients with chronic obstructive pulmonary disease (COPD) and affects both ventilatory and nonventilatory muscle groups. It represents a very important comorbidity that is associated with poor quality of life and reduced survival. It results from a complex combination of functional, metabolic, and anatomical alterations leading to suboptimal muscle work. Muscle atrophy, altered fiber type and metabolism, and chest wall remodeling, in the case of the respiratory muscles, are relevant etiological contributors to this process. Muscle dysfunction worsens during COPD exacerbations, rendering patients progressively less able to perform activities of daily living, and it is also associated with poor outcomes. Muscle recovery measures consisting of a combination of pulmonary rehabilitation, optimized nutrition, and other strategies are associated with better prognosis when administered in stable patients as well as after exacerbations. A deeper understanding of this process' pathophysiology and clinical relevance will facilitate the use of measures to alleviate its effects and potentially improve patients' outcomes. In this review, a general overview of skeletal muscle dysfunction in COPD is offered to highlight its relevance and magnitude to expert practitioners and scientists as well as to the average clinician dealing with patients with chronic respiratory diseases.

Sports psychiatry: mental health and mental disorders in athletes and exercise treatment of mental disorders

Sports psychiatry has developed for the past 3 decades as an emerging field within psychiatry and sports medicine. An International society has been established in 1994 and also national interest groups were implemented, mostly within the national organizations for psychiatry, some also containing the topic of exercise treatment of mental disorders. Where are we now 30 years later? We systematically but also selectively review the medical literature on exercise, sport, psychiatry, mental health and mental disorders and related topics. The number of publications in the field has increased exponentially. Most topics keep remaining on the agenda, e.g., head trauma and concussion, drug abuse and doping, performance enhancement, overtraining, ADHD or eating disorders. Supported by the growing literature, evidence-based recommendations have become available now in many clinical areas. A relatively new phenomenon is muscle dysmorphia, observed in weightlifters, bodybuilders but also in college students and gym users. Further, sports therapy of mental disorders has been studied by more and more high-quality randomized controlled clinical trials. Mostly as a complementary treatment, however, for some disorders already with a 1a evidence level, e.g., depression, dementia or MCI but also post-traumatic stress disorder. Being grown up and accepted nowadays, sports psychiatry still represents a fast-developing field. The reverse side of the coin, sport therapy of mental disorders has received a scientific basis now. Who else than sports psychiatry could advance sport therapy of mental disorders? We need this enthusiasm for sports and psychiatry for our patients with mental disorders and it is time now for a broadening of the scope. Optimized psychiatric prevention and treatment of athletes and ideal sport-related support for individuals with mental disorders should be our main purpose and goal.

Effects of breathing exercises using home-based positive pressure in the expiratory phase in patients with COPD

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) commonly have higher intrinsic positive end-expiratory pressure (PEEPi). A breathing exercise programme strategy employing an appropriate PEEP may improve their pulmonary functional capacity, exercise tolerance and health-related quality of life. Breathing with an expiratory resistive load, which is a method of modulating spontaneous breathing against PEEPi, has not been fully studied in patients with COPD. The objective of this study was to investigate the role of changing spontaneous breathing in home-based conditions and regulating spontaneous breathing with breathing exercises in patients with COPD.

METHODS

This was a prospective randomised trial including 64 patients with a diagnosis of stage III or IV COPD. Patients were randomised into two groups: standard treatment and standard treatment combined with breathing exercise rehabilitation. The effects of the treatments on the COPD assessment test (CAT) score, 6-minute walk test (6MWT) results and pulmonary function were compared at 0, 6, 12 and 18 months within and between the two groups.

RESULTS

All outcomes showed no significant differences between the two groups at the beginning of the study, while the 6MWT and CAT scores exhibited clinically and statistically significant improvements (p<0.001) by the end of the study. At month 18, the change in the predicted percentage of forced expiratory volume in 1 s (FEV₁%pred) differed between the two groups (p<0.05). In addition, there were statistically significant differences in the 6MWT results, CAT scores and FEV₁%pred values between the baseline and month 18 (p<0.0001) in the intervention group.

CONCLUSIONS

Improvements in 6MWT results, pulmonary function and CAT scores are associated with a successful response to breathing against PEEPi in patients with COPD.

TRIAL REGISTRATION

This trial was registered at research registry.com (identifier research registry 4816).

Deterioration of Limb Muscle Function during Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Important features of both stable and acute exacerbation of chronic obstructive pulmonary disease (COPD) are skeletal muscle weakness and wasting. Limb muscle dysfunction during an exacerbation has been linked to various adverse outcomes, including prolonged hospitalization, readmission, and mortality. The contributing factors leading to muscle dysfunction are similar to those seen in stable COPD: disuse, nutrition/energy balance, hypercapnia, hypoxemia, electrolyte derangements, inflammation, and drugs (i.e., glucocorticoids). These factors may be the trigger for a downstream cascade of local inflammatory changes, pathway process alterations, and structural degradation. Ultimately, the clinical effects can be wide ranging and include reduced limb muscle strength. Current therapies, such as pulmonary/physical rehabilitation, have limited impact because of low participation rates. Recently, novel drugs have been developed in similar disorders, and learnings from these studies can be used as a foundation to facilitate discovery in patients hospitalized with a COPD exacerbation. Nevertheless, investigators should approach this patient population with knowledge of the limitations of each intervention. In this Concise Clinical Review, we provide an overview of acute muscle dysfunction in patients hospitalized with acute exacerbation of COPD and a strategic approach to drug development in this setting.

Impact of transcutaneous neuromuscular electrical stimulation or resistance exercise on skeletal muscle mRNA expression in COPD

Background: Voluntary resistance exercise (RE) training increases muscle mass and strength in patients with chronic obstructive pulmonary disease (COPD). Nonvolitional transcutaneous neuromuscular electrical stimulation (NMES) may be an alternative strategy for reducing ambulatory muscle weakness in patients unable to perform RE training, but little comparative data are available. This study, therefore, investigated changes in muscle mRNA abundance of a number of gene targets in response to a single bout of NMES compared with RE. Methods: Twenty-six patients with stable COPD (15 male; FEV₁, 43±18% predicted; age, 64±8 years; fat free mass index, 16.6±1.8 kg/m²) undertook 30 minutes of quadriceps NMES (50 Hz, current at the limit of tolerance) or 5×30 maximal voluntary isokinetic knee extensions. Vastus lateralis muscle biopsies were obtained at rest immediately before and 24 hours after intervention. Expression of 384 targeted mRNA transcripts was assessed by real time TaqMan PCR. Significant change in expression from baseline was determined using the ΔΔC_T method with a false discovery rate (FDR) of <5%. Results: NMES and RE altered mRNA abundance of 18 and 68 genes, respectively (FDR <5%), of which 14 genes were common to both interventions and of the same magnitude of fold change. Biological functions of upregulated genes included inflammation, hypertrophy, muscle protein turnover, and muscle growth, whilst downregulated genes included mitochondrial and cell signaling functions. Conclusions: Compared with NMES, RE had a broader impact on mRNA abundance and, therefore, appears to be the superior intervention for maximizing transcriptional responses in the quadriceps of patients with COPD. However, if voluntary RE is not feasible in a clinical setting, NMES by modifying expression of genes known to impact upon muscle mass and strength may have a positive influence on muscle function.

A home-based lower limb-specific resistance training programme for patients with COPD: an explorative feasibility study

Peripheral muscle weakness leading to poor exercise tolerance is a significant problem in patients with chronic obstructive pulmonary disease (COPD). Increased lower limb strength following pulmonary rehabilitation (PR) has been shown to be associated with positive outcomes [1]. Despite this, access to and completion of PR remains problematic and alternative exercise interventions are sought. Elastic band resistance training has recently been shown to be as effective as conventional outpatient free-weight exercise training [2–4]. Elastic band resistance training may, therefore, provide an alternative home-based exercise intervention for patients with COPD who are unable or unwilling to participate in PR due to significant symptom burden or anxiety in attending group classes

It is feasible and acceptable to deliver a home-based lower limb-specific resistance training (LLSRT) programme to patients with COPD. Individual patient improvements in walking distance and breathlessness severity were observed post-LLSRT intervention.http://bit.ly/30xYpWI

Nutrition-related factors associated with waiting list mortality in patients with interstitial lung disease: A retrospective cohort study

Japanese patients with interstitial lung disease (ILD) sometimes die waiting for lung transplantation (LTx) because it takes about 2 years to receive it in Japan. We evaluated nutrition-related factors associated with waiting list mortality. Seventy-six ILD patients were hospitalized in Kyoto University Hospital at registration for LTx from 2013 to 2015. Among them, 40 patients were included and analyzed. Patient background was as follows: female, 30%; age, 50.3 ± 6.9 years; body mass index, 21.1 ± 4.0 kg/m² ; 6-minute walk distance (6MWD), 356 ± 172 m; serum albumin, 3.8 ± 0.4 g/dL; serum transthyretin (TTR), 25.3 ± 7.5 mg/dL; and C-reactive protein, 0.5 ± 0.5 mg/dL. Median observational period was 497 (range 97-1015) days, and median survival time was 550 (95% CI 414-686) days. Survival rate was 47.5%, and mortality rate was 38.7/100 person-years. Cox analyses showed that TTR (HR 0.791, 95% CI 0.633-0.988) and 6MWD (HR 0.795, 95% CI 0.674-0.938) were independently correlated with mortality and were influenced by body fat mass and leg skeletal muscle mass, respectively. It is suggested that nutritional markers and exercise capacity are important prognostic markers in waitlisted patients, but further study is needed to determine whether nutritional intervention or exercise can change outcomes.