S18 Neuromuscular electrical stimulation in advanced idiopathic pulmonary fibrosis (IPF): a randomised placebo-controlled feasibility trial

Background

Pulmonary rehabilitation is associated with benefit in IPF. However, those with advanced disease may have difficulties participating as ventilatory limitation may restrict whole-body exercise. Neuromuscular electrical stimulation (NMES) offers a home-based rehabilitation strategy to enhance muscle strength that is unaffected by ventilatory limitation. We aimed to investigate whether home-based NMES is acceptable to people with IPF, and whether it brings improved physical performance, muscle strength and quality of life to those with severe breathlessness.

Methods

We undertook a parallel-group, randomised placebo-controlled, assessor-blinded feasibility trial with participants randomised (1:1) to usual care (unsupervised home-based exercise training with exercise manual and weekly telephone support) with either placebo or active NMES (30 minutes daily stimulation of quadriceps) for six weeks, with 12 week follow-up and embedded, topic-guided, qualitative interviews. The primary outcomes were feasibility measures: patient flow and recruitment, intervention uptake, assessor and participant blinding, completion rates. Secondary outcomes included clinical measures (six minute walk test (6MWT), accelerometer-measured physical activity levels quadriceps maximum voluntary contraction, rectus femoris cross-sectional area, Kings Brief Interstitial Lung Disease questionnaire) measured at baseline, six and 12 weeks.

Results

Feasibility outcomes are shown in figure 1. The groups were well-matched at baseline, but the intervention group had a higher median (25th, 75th centile) 6MWT distance than the control group (326 (150, 361) versus 240 (130, 325) metres). The assessor remained blinded to group allocation but three (27%) patients in the control group were unblinded. There was no significant between-group differences in device use or home-exercise performance. Due to the small numbers of participants in each group, it was not possible to test for within- or between-group differences. However, there was a trend towards a greater reduction in time spent sedentary in the intervention group. Four patients in the control group experienced a serious adverse event compared to one patient in the intervention group. Analysis of qualitative interviews (n=6) indicated that that the intervention was acceptable and feasible to patients but many found the telephone support and home-exercise diary burdensome.

Conclusion

This study, although acceptable to patients, should not be developed into a definitive trial because of recruitment challenges.