Endobronchial valve treatment improves diaphragm function in severe emphysema patients

<bold>Introduction</bold> Diaphragm dysfunction is common in severe emphysema patients, primarily due to hyperinflation, placing the diaphragm at a mechanical disadvantage. Endobronchial valve (EBV) treatment is a bronchoscopic treatment modality to reduce hyperinflation in this patient population. <bold>Aim</bold> To study the effect of EBV treatment on diaphragm function. <bold>Methods</bold> We performed a prospective study in which diaphragm function was measured at baseline and 6 weeks after EBV treatment by: maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), ultrasound to assess diaphragm motion, and surface electromyography to quantify diaphragm activity. <bold>Results</bold> We included 25 patients. MIP (+0.6kPa, P=0.001, range -1.2–2.8) and MEP (+0.4kPa, P=0.035, range -1.6–4.7) increased significantly 6 weeks post EBV treatment (Table). Diaphragm motion during tidal breathing (−3.3mm, P=0.023, range -24.7–14.6), as well as the ratio tidal breathing/maximal inspiration (−0.12, P=0.001, range −0.45–0.19) decreased significantly (Table). Moreover, diaphragm activity for tidal breathing (−1.6µV, P=0.007, range -8.8–5.8), maximal inspiration (−3.3µV, P=0.008, range -42.3–16.0), and sniff manoeuvre (−5.9µV, P=0.045, range -42.2–24.2) significantly decreased, implicating less respiratory effort by the patient post treatment (Table). <bold>Conclusions</bold> Our results show that diaphragm function significantly improves after EBV treatment in severe emphysema patients. <fig><object-id>erj;64/suppl_68/PA4349/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>