Long-term outcomes of home mechanical ventilation in Duchenne Muscular Dystrophy – an observational study

BACKGROUND AND METHODS: Home-mechanical-ventilation in Duchenne muscular dystrophy improves survival and quality of life. In this observational study in Duchenne muscular dystrophy patients, lung function and respiratory muscle strength at the time of ventilation-initiation and their change under home-mechanical-ventilation were investigated. Main outcomes of interest were age and pulmonary function at the time of ventilation-initiation. RESULTS: Age at start of nocturnal home-mechanical-ventilation was 19.8 ± 4.8 years (n = 80) and 23.8 ± 5.4 years when home-mechanical-ventilation was extended to daytime (63/80). 25/80 patients were ventilated via tracheostomy (8% initially, 92% switched after 86 ± 46 months of non-invasive ventilation). Forced vital capacity, maximal inspiratory pressure and sniff nasal pressure at the start of home-mechanical-ventilation were 21 ± 13% predicted, -26.9 ± 15.4 cmH2O, and -20.3 ± 11.7 cmH2O, respectively. Forced vital capacity was an independent negative predictor of sleep-hypoventilation, even after adjustment for body-mass-index and age, whereas inspiratory muscle strength measures were not. Starting home-mechanical-ventilation slowed the decline in forced vital capacity and inspiratory muscle strength. Median survival was 33 (28-39) years. CONCLUSIONS: In summary, indication of home-mechanical-ventilation can be expected at a median age of 20 (16-22) years and at a forced vital capacity of 18% (12-20) predicted in Duchenne muscular dystrophy. Initiation of home-mechanical-ventilation slows the decline in lung function.