Lung volume reduction in emphysema improves chest wall asynchrony

Abstract

BACKGROUND: Lung volume reduction (LVR) techniques improve lung function in selected patients with emphysema, but the impact of LVR procedures on the asynchronous movement of different chest wall compartments, which is a feature of emphysema, is not known. METHODS: We used optoelectronic plethysmography to assess the effect of surgical and bronchoscopic LVR on chest wall asynchrony. Twenty-six patients were assessed before and 3 months after LVR (surgical [n = 9] or bronchoscopic [n = 7]) or a sham/unsuccessful bronchoscopic treatment (control subjects, n = 10). Chest wall volumes were divided into six compartments (left and right of each of pulmonary ribcage [Vrc,p], abdominal ribcage [Vrc,a], and abdomen [Vab]) and phase shift angles (Θ) calculated for the asynchrony between Vrc,p and Vrc,a (ΘRC), and between Vrc,a and Vab (ΘDIA). RESULTS: Participants had an FEV1 of 34.6 ± 18% predicted and a residual volume of 217.8 ± 46.0% predicted with significant chest wall asynchrony during quiet breathing at baseline (ΘRC, 31.3° ± 38.4°; and ΘDIA, -38.7° ± 36.3°). Between-group difference in the change in ΘRC and ΘDIA during quiet breathing following treatment was 44.3° (95% CI, - 78 to - 10.6; P = .003) and 34.5° (95% CI, 1.4 to 67.5; P = .007) toward 0° (representing perfect synchrony), respectively, favoring the LVR group. Changes in ΘRC and ΘDIA were statistically significant on the treated but not the untreated sides. CONCLUSIONS: Successful LVR significantly reduces chest wall asynchrony in patients with emphysema.