A Randomized Controlled Clinical Trial of Lung Volume Recruitment in Adults with Neuromuscular Disease

Rationale: Clinical care guidelines advise that lung volume recruitment (LVR) be performed routinely by people with neuromuscular disease (NMD) to maintain lung and chest wall flexibility and slow lung function decline. However, the evidence base is limited, and no randomized controlled trials of regular LVR in adults have been published. Objectives: To evaluate the effect of regular LVR on respiratory function and quality of life in adults with NMD. Methods: A randomized controlled trial with assessor blinding was conducted between September 2015 and May 2019. People (>14 years old) with NMD and vital capacity,80% predicted were eligible, stratified by disease subgroup (amyotrophic lateral sclerosis/motor neuron disease or other NMDs), and randomized to 3months of twice-daily LVR or breathing exercises. The primary outcome was change in maximum insufflation capacity (MIC) from baseline to 3months, analyzed using a linear mixed model approach. Results: Seventy-six participants (47% woman; median age, 57 [31-68] years; mean baseline vital capacity, 40618% predicted) were randomized (LVR, n = 37). Seventy-three participants completed the study. There was a statistically significant difference in MIC between groups (linearmodel interaction effect P = 0.002, observed mean difference, 0.19 [0.00-0.39] L). MIC increased by 0.13 (0.01-0.25) L in the LVR group, predominantly within the first month. No interaction or treatment effects were observed in secondary outcomes of lung volumes, respiratory systemcompliance, and quality of life. No adverse events were reported. Conclusions: Regular LVR increased MIC in a sample of LVR-naive participants with NMD. We found no direct evidence that regular LVR modifies respiratory mechanics or slows the rate of lung volume decline. The implications of increasing MIC are unclear, and the change in MIC may represent practice. Prospective long-term clinical cohorts with comprehensive follow-up, objective LVR use, and clinically meaningful outcome data are needed.