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Is transcutaneous muscle electrical stimulation useful in patients with severe COPD?
ARTICLE IN PRESS 156
Literature review
Commentary by Irfan Rahman Assistant Professor of Environmental Medicine Lung Biology and Disease Program, University of Rochester Medical Center, USA Abnormal airway inflammation and excessive production of reactive oxygen and nitrogen species are involved in the pathogenesis of COPD. Inhibition of inflammatory mediators, and oxidative and nitrosative processes may prove to be beneficial in controlling the progressive decline in lung function in patients with COPD. So far, antioxidants, particularly N-acetyl-L-cysteine, individually or in combination and glucocorticoids (GC), have been tested against moderate to severe COPD symptoms yielding unreliable results. This is largely due to poor bioavailability of antioxidants and unresponsiveness of GC to control airway inflammation and oxidative/nitrosative stress in the airways. The study by Hirano et al. is important and timely as it shows that theophylline (oral 200 mg twice daily), in comparison to fluticasone propionate (inhaled 200 mg twice daily) for 4 weeks in a randomized cross-sectional study, suppressed airway inflammation (number of neutrophils) and reactive nitrogen species (3-nitrotyrosine levels) in induced sputum in 16 COPD patients. There was no beneficial effect of these drugs on either FEV1 or FVC after this short period of administration. However, the study did not address the combination therapy of these drugs. This study may help to reinforce the contention that GC are largely ineffective in resolving chronic inflammation whereas theophylline may be effective in at least controlling neutrophilic inflammation and toxic nitric oxide mediators, and possibly will improve the efficacy of GC (smoking interferes with GC action). However, further large, long-term and placebocontrolled studies with different regimens of theophylline and GC on various GOLD stages of COPD patients are immediately warranted in order to validate the effectiveness of this drug in COPD.
Original article reference: Hirano T, Yamagata T, Gohda M, Yamagata Y, Ichikawa T, Yanagisawa S, et al. Inhibition of reactive nitrogen species production in COPD airways: comparison of inhaled corticosteroid and oral theophylline. Thorax 2006;61:761–6. 10.1016/j.rmedu.2006.11.008
Is transcutaneous muscle electrical stimulation useful in patients with severe COPD?
This study investigated whether transcutaneous muscle electrical stimulation (ES) enhances the effect of a usual pulmonary rehabilitation program (UR) in severely disabled COPD patients with low BMI. Previous studies had focused on ES alone. It found that a combination of ES and UR led to a greater improvement in quadriceps strength and dyspnea when carrying out daily tasks, than UR alone.
Abstract of Original Article Study objective: Low body weight in COPD patients is associated with worsening dyspnea, reduced leg strength, and poor prognosis. Classical rehabilitation strategies are then limited by reduced exercise tolerance. Thus, we proposed to evaluate whether electrostimulation (ES) was a beneficial technique in the rehabilitation programs for severely deconditioned COPD patients after an acute exacerbation. Design: Randomized, controlled study.
Setting: Pulmonary rehabilitation center. Patients: Seventeen patients with severe COPD (mean [7SD] FEV1, 3073% predicted) and low body mass index (BMI) [1872.5 kg/m2]. Methods: Patients were randomly assigned either to usual rehabilitation (UR) alone or to a UR-plus-ES program for 4 weeks. Quadriceps muscle strength, total muscle mass (MM), exercise capacity, and health-related quality of life were measured before and after rehabilitation.
ARTICLE IN PRESS Literature review Results: The training with ES plus UR induced a significant twofold improvement in the mean number of maximal voluntary contraction (MVC) compared to UR alone (97771 vs. 36734 contractions, respectively; p ¼ 0.03) and resulted in a more significant improvement in dyspnea when performing daily tasks (decrease in the dyspnea domain score of the 28item Maugeri Foundation Respiratory Failure questionnaire, 1.771.0 vs. 0.271.2 points, respectively; p ¼ 0.05). There was also a significant increase in walking distance (63740 m; p ¼ 0.01) and BMI (0.670.5 kg/m2; p ¼ 0.02) after training in the ES+UR group. A significant relationship was found
157 between changes in MVC and changes in MM after training in the ES+UR group (r ¼ 0.94; p ¼ 0.03). Conclusions: The combination of ES and UR was associated with greater improvement in quadriceps strength and dyspnea during the performance of daily tasks than UR alone in severely disabled COPD patients with low BMI. In this population, ES has been revealed as a useful procedure, complementing the usual pulmonary rehabilitation. Reproduced with permission from the American College of Chest Physicians.
Commentary by Thomas Jagoe Senior Lecturer and Honorary Consultant, University of Liverpool and Aintree Chest Centre, Liverpool Prior studies have suggested transcutaneous muscle electrical stimulation (ES) alone can improve muscle function and reduce dyspnea in non-depleted patients with severe COPD. Given that ES is a practical and logical mode of treatment, it is puzzling that its usage is not more widespread, and that progress in defining its role has been so slow. This study focuses on subjects with severe COPD, very poor functional state with reduced quadriceps strength and nutritional depletion. The authors attempted to determine whether ES enhances the effects of a normal pulmonary rehabilitation program. Subjects were recruited after admission for an acute exacerbation, but the time interval between exacerbation and intervention is unclear. Furthermore, no sham ES was offered, and anthropometric measures of limb fat and muscle mass were only performed on a subset of patients. Despite these reservations, after 4 weeks’ treatment, additional improvement in muscle strength, walking distance and dyspnea were observed in those receiving ES. Much remains to be defined about ES as a treatment modality in COPD, including the optimum stimulation sites, frequency, contraction-relaxation ratio, and treatment duration. However, there does seem to be a message emerging that for severely functionally impaired patients with COPD, ES is a potentially useful treatment either alone or in combination with pulmonary rehabilitation.
Original article reference: Vivodtzev I, Pepin JL, Vottero G, Mayer V, Porsin B, Levy P, et al. Improvement in quadriceps strength and dyspnea in daily tasks after 1 month of electrical stimulation in severely deconditioned and malnourished COPD. Chest 2006;129:1540–8.
10.1016/j.rmedu.2006.11.009
Can FOT reliably detect EFL in COPD?
This study examined the role of Forced Oscillation Technique (FOT) in detecting expiratory flow limitation (EFL) in COPD patients receiving non-invasive ventilation support. The results suggest that it may be a useful technique, with the potential to be used in clinical practice.
Literature review
Commentary by Irfan Rahman Assistant Professor of Environmental Medicine Lung Biology and Disease Program, University of Rochester Medical Center, USA Abnormal airway inflammation and excessive production of reactive oxygen and nitrogen species are involved in the pathogenesis of COPD. Inhibition of inflammatory mediators, and oxidative and nitrosative processes may prove to be beneficial in controlling the progressive decline in lung function in patients with COPD. So far, antioxidants, particularly N-acetyl-L-cysteine, individually or in combination and glucocorticoids (GC), have been tested against moderate to severe COPD symptoms yielding unreliable results. This is largely due to poor bioavailability of antioxidants and unresponsiveness of GC to control airway inflammation and oxidative/nitrosative stress in the airways. The study by Hirano et al. is important and timely as it shows that theophylline (oral 200 mg twice daily), in comparison to fluticasone propionate (inhaled 200 mg twice daily) for 4 weeks in a randomized cross-sectional study, suppressed airway inflammation (number of neutrophils) and reactive nitrogen species (3-nitrotyrosine levels) in induced sputum in 16 COPD patients. There was no beneficial effect of these drugs on either FEV1 or FVC after this short period of administration. However, the study did not address the combination therapy of these drugs. This study may help to reinforce the contention that GC are largely ineffective in resolving chronic inflammation whereas theophylline may be effective in at least controlling neutrophilic inflammation and toxic nitric oxide mediators, and possibly will improve the efficacy of GC (smoking interferes with GC action). However, further large, long-term and placebocontrolled studies with different regimens of theophylline and GC on various GOLD stages of COPD patients are immediately warranted in order to validate the effectiveness of this drug in COPD.
Original article reference: Hirano T, Yamagata T, Gohda M, Yamagata Y, Ichikawa T, Yanagisawa S, et al. Inhibition of reactive nitrogen species production in COPD airways: comparison of inhaled corticosteroid and oral theophylline. Thorax 2006;61:761–6. 10.1016/j.rmedu.2006.11.008
Is transcutaneous muscle electrical stimulation useful in patients with severe COPD?
This study investigated whether transcutaneous muscle electrical stimulation (ES) enhances the effect of a usual pulmonary rehabilitation program (UR) in severely disabled COPD patients with low BMI. Previous studies had focused on ES alone. It found that a combination of ES and UR led to a greater improvement in quadriceps strength and dyspnea when carrying out daily tasks, than UR alone.
Abstract of Original Article Study objective: Low body weight in COPD patients is associated with worsening dyspnea, reduced leg strength, and poor prognosis. Classical rehabilitation strategies are then limited by reduced exercise tolerance. Thus, we proposed to evaluate whether electrostimulation (ES) was a beneficial technique in the rehabilitation programs for severely deconditioned COPD patients after an acute exacerbation. Design: Randomized, controlled study.
Setting: Pulmonary rehabilitation center. Patients: Seventeen patients with severe COPD (mean [7SD] FEV1, 3073% predicted) and low body mass index (BMI) [1872.5 kg/m2]. Methods: Patients were randomly assigned either to usual rehabilitation (UR) alone or to a UR-plus-ES program for 4 weeks. Quadriceps muscle strength, total muscle mass (MM), exercise capacity, and health-related quality of life were measured before and after rehabilitation.
ARTICLE IN PRESS Literature review Results: The training with ES plus UR induced a significant twofold improvement in the mean number of maximal voluntary contraction (MVC) compared to UR alone (97771 vs. 36734 contractions, respectively; p ¼ 0.03) and resulted in a more significant improvement in dyspnea when performing daily tasks (decrease in the dyspnea domain score of the 28item Maugeri Foundation Respiratory Failure questionnaire, 1.771.0 vs. 0.271.2 points, respectively; p ¼ 0.05). There was also a significant increase in walking distance (63740 m; p ¼ 0.01) and BMI (0.670.5 kg/m2; p ¼ 0.02) after training in the ES+UR group. A significant relationship was found
157 between changes in MVC and changes in MM after training in the ES+UR group (r ¼ 0.94; p ¼ 0.03). Conclusions: The combination of ES and UR was associated with greater improvement in quadriceps strength and dyspnea during the performance of daily tasks than UR alone in severely disabled COPD patients with low BMI. In this population, ES has been revealed as a useful procedure, complementing the usual pulmonary rehabilitation. Reproduced with permission from the American College of Chest Physicians.
Commentary by Thomas Jagoe Senior Lecturer and Honorary Consultant, University of Liverpool and Aintree Chest Centre, Liverpool Prior studies have suggested transcutaneous muscle electrical stimulation (ES) alone can improve muscle function and reduce dyspnea in non-depleted patients with severe COPD. Given that ES is a practical and logical mode of treatment, it is puzzling that its usage is not more widespread, and that progress in defining its role has been so slow. This study focuses on subjects with severe COPD, very poor functional state with reduced quadriceps strength and nutritional depletion. The authors attempted to determine whether ES enhances the effects of a normal pulmonary rehabilitation program. Subjects were recruited after admission for an acute exacerbation, but the time interval between exacerbation and intervention is unclear. Furthermore, no sham ES was offered, and anthropometric measures of limb fat and muscle mass were only performed on a subset of patients. Despite these reservations, after 4 weeks’ treatment, additional improvement in muscle strength, walking distance and dyspnea were observed in those receiving ES. Much remains to be defined about ES as a treatment modality in COPD, including the optimum stimulation sites, frequency, contraction-relaxation ratio, and treatment duration. However, there does seem to be a message emerging that for severely functionally impaired patients with COPD, ES is a potentially useful treatment either alone or in combination with pulmonary rehabilitation.
Original article reference: Vivodtzev I, Pepin JL, Vottero G, Mayer V, Porsin B, Levy P, et al. Improvement in quadriceps strength and dyspnea in daily tasks after 1 month of electrical stimulation in severely deconditioned and malnourished COPD. Chest 2006;129:1540–8.
10.1016/j.rmedu.2006.11.009
Can FOT reliably detect EFL in COPD?
This study examined the role of Forced Oscillation Technique (FOT) in detecting expiratory flow limitation (EFL) in COPD patients receiving non-invasive ventilation support. The results suggest that it may be a useful technique, with the potential to be used in clinical practice.