Neuromuscular electrical stimulation is effective in maintaining physical capacity during an exacerbation of chronic obstructive pulmonary disease - a pilot study

  • Jennie Bradshaw

    Student thesis: Master's ThesisMaster of Science by Research

    Abstract

    Background: Pulmonary rehabilitation for patients with Chronic Obstructive Pulmonary Disease (COPD) traditionally incorporates exercise training. Since COPD is characterised by periods of exacerbation of their disease, at this time patients may be unable to complete any exercise due to breathlessness or peripheral muscle weakness. Neuromuscular Electrical Stimulation (NMES) has been shown to improve the fundamental properties of muscles; therefore it has been hypothesised that NMES of the quadriceps femoris muscles may be able to maintain physical capacity during an exacerbation of COPD. 
    Methods: A randomised controlled trial was designed. A sample of 20 participants of mean (SD) age 70.5 (9.3)yrs admitted to hospital with an acute exacerbation of COPD (mean (SD) Forced Expiratory Volume in 1 second (FEV1) 0.82 (0.39) (30.4% predicted) were recruited. The group were randomised into an experimental group who undertook NMES of the quadriceps for 30 minutes each day, and were also encouraged to mobilise until constrained by symptoms; or randomised into a control group who undertook NMES using a ‘sham’ technique as well as being encouraged to mobilise until constrained by symptoms. Patients participated in the study for 4 weeks. Quadriceps strength, and exercise capacity measured by Incremental Shuttle Walk Test (ISWT) were taken at baseline, on discharge from hospital and at 4 week follow-up. Patients also completed health related quality of life questionnaires, and were asked to wear an activity monitor during their in-patient stay. 
    Results: There were no significant differences between the baseline measurements. In the experimental group (n=8) over the 4 week trial period there was an overall increase in quadriceps strength of 9.1 (SD 15.5)Nm (95%CI –22.0 to 3.9). The control group (n=5) also demonstrated an increase in quadriceps strength 37.4Nm (SD 104.6) (95%CI -203.9 to 129.0). However neither of these increases were significant p<0.05, there were no differences between groups. ISWT performance was also improved in the experimental group, at baseline the mean (SD) distance was 21.0 (n=8) (SD 37.8)m. On discharge from hospital the mean had increased to 61.0 (SD 49.0)m (mean increase 40m) (95%CI –81.2 to1.2). This increase was not significant (p=0.056 (df=9), results showed a strong trend towards statistical significance. During the period from discharge to 4 weeks there was a significant increase in ISWT performance p=0.026 (df=5). The ISWT in the control group also increased again this was not a significant increase, mean baseline ISWT was 10.0 (n=5) (SD 20.0)m (95%CI –291.7 to 81.7), at discharge the mean distance was 115.0 (SD 109.1)m (mean increase of 105m n=5) and at 4 weeks the mean distance was 100.0 (SD 93.0)m (a mean increase of 90m from baseline to 4 weeks) from baseline to 4 weeks p=0.106 (df=4) (CI –214.7 to 30.7). There were no statistically significant improvements in health related quality of life, however there were clinically significant improvements (>0.5 change in score) in the mastery domain of the Chronic Respiratory Questionnaire (CRQ-SR) following NMES. Conclusion: This study has demonstrated that NMES is feasible during an acute exacerbation of COPD to maintain physical capacity, although it is difficult to draw conclusions from, as the groups were small.
    Date of Award2010
    Original languageEnglish
    Awarding Institution
    • Coventry University
    SponsorsGlenfield Hospital
    SupervisorSally Singh (Supervisor)

    Keywords

    • physiology
    • neuromuscular stimulation
    • pulmonary disease
    • COPD

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