Neuromuscular electrical stimulation to improve exercise capacity in patients with severe COPD: a randomised double-blind, placebo-controlled trial
Matthew Maddocks, Claire M. Nolan, William D-C. Man, Michael I. Polkey, Nicholas Hart, Wei Gao, Gerrard F. Rafferty, John Moxham, Irene J. Higginson
Published in the journal Lancet Respiratory Medicine, published online December 14th 2015
Patients with severe COPD often have weak legs as breathlessness can limit their ability to be active. Normally, to combat this and other symptoms of COPD, exercise classes called Pulmonary Rehabilitation (PR) are carried out. However, more severely affected patients may struggle to do PR.
An alternative therapy was introduced, neuromuscular electrical stimulation (NMES), to COPD patients with more severe symptoms. NMES is when electricity is used to create muscle contractions, in this case in the thigh muscles. While NMES has been used to strengthen muscles in previous research, this trial is the first to explore the impact on daily activities and the first to investigate the longer-term impact of the treatment.
52 participants with very severe COPD took part in this trial over two years. Participants received 30 minutes of NMES to both sets of thigh muscles daily for 6 weeks; 27 were placebo (‘sham’ stimulation) and 25 received active NMES. The aim: to assess the effectiveness of NMES, as a therapy to be conducted unsupervised at home, and at aiding daily activities. The main measure of effectiveness in this trial was a test of how far participants could walk in 6 minutes.
The results of the walk tests strongly support the use of NMES for severe COPD patients, with the patients who received the active NMES being able to walk substantially further. During interviews active NMES participants expressed a greater ease in everyday tasks (such as climbing the stairs) and stated that they could carry out physical activities for longer. No participants reported any negative views. Unfortunately, the improvement provided by NMES quickly waned after the treatment had stopped. Therefore, all existing evidence suggests that NMES should not be considered a replacement for PR. NMES can be used as an extension to PR, and could be used when patients are unable to take part in PR programmes. In addition, the short duration of effect suggests that longer programmes need to be investigated. Nonetheless, this trial has shown that NMES is a practical home-based therapy, suited to patients with more severe symptoms and has gives suggestions for future research.
This summary was produced by Reef Ronel, Year 12 student from JFS School, as part of our departmental educational outreach programme.