Influence of heart failure on resting lung volumes in patients with COPD

• Autor(a) principal: de Souza, Aline Soares [UNIFESP]
• Data de Publicação: 2016
• Outros Autores: Sperandio, Priscila Abreu [UNIFESP], Mazzuco, Adriana [UNIFESP], Alencar, Maria Clara [UNIFESP], Arbex, Flavio Ferlin [UNIFESP], de Oliveira, Mayron Faria [UNIFESP], O'Donnell, Denis Eunan, Neder, Jose Alberto [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng; por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1590/S1806-37562015000000290; https://repositorio.unifesp.br/handle/11600/57650
• topic: Respiratory function tests; Pulmonary disease, chronic obstructive; Heart failure; Spirometry; Testes de função respiratória; Doença pulmonar obstrutiva crônica; Insuficiência cardíaca; Espirometria

Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil.