Fregonezi Guilherme, Sarmento Antonio, Pinto Janaína, LoMauro Antonella, Resqueti Vanessa, Aliverti Andrea
PneumoCardioVascular Lab, Hospital Universitário Onofre Lopes, Empresa Brasileira de Serviços Hospitalares, Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
Front Physiol. 2018 Jun 13;9:719. doi: 10.3389/fphys.2018.00719. eCollection 2018.
This study aimed to better understand how subjects with stable asthma and without exercise-induced bronchoconstriction respond to mild exercise. Breathing pattern, chest wall compartmental and operational volumes, and thoracoabdominal asynchrony were assessed in 11 stable asthmatic subjects and 10 healthy subjects at rest and during exercise in a cycle-ergometer through optoelectronic plethysmography. Dyspnea and sensation of leg effort were assessed through Borg scale. During exercise, with similar minute ventilation, a significant lower chest wall tidal volume ( = 0.003) as well as a higher respiratory rate ( < 0.05) and rapid shallow breathing ( < 0.05) were observed in asthmatic when compared to healthy subjects. Asthmatic subjects exhibited a significantly lower inspiratory ( < 0.05) and expiratory times ( < 0.05). Intergroup analysis found a significant higher end-expiratory chest wall volume in asthmatic subjects, mainly due to a significant increase in volume of the pulmonary ribcage (RCp; 170 ml, = 0.002), indicating dynamic hyperinflation (DH). Dyspnea and sensation of leg effort were both significantly greater ( < 0.0001) in asthmatic when compared to healthy subjects. In addition to a higher thoracoabdominal asynchrony found between RCp and abdominal (AB) ( < 0.005) compartments in asthmatic subjects, post-inspiratory action of the inspiratory ribcage and diaphragm muscles were observed through the higher expiratory paradox time of both RCp ( < 0.0001) and AB ( = 0.0002), respectively. Our data suggest that a different breathing pattern is adopted by asthmatic subjects without exercise-induced bronchoconstriction during mild exercise and that this feature, associated with DH and thoracoabdominal asynchrony, contributes significantly to exercise limitation.
本研究旨在更好地了解稳定期哮喘且无运动诱发支气管收缩的受试者对轻度运动的反应。通过光电体积描记法，对11名稳定期哮喘受试者和10名健康受试者在静息状态及在功率自行车上运动期间的呼吸模式、胸壁腔室和操作容积以及胸腹不同步情况进行了评估。通过Borg量表评估呼吸困难和腿部用力感觉。运动期间，在分钟通气量相似的情况下，与健康受试者相比，哮喘患者的胸壁潮气量显著降低（ = 0.003），呼吸频率更高（ < 0.05）且呼吸急促（ < 0.05）。哮喘患者的吸气时间（ < 0.05）和呼气时间（ < 0.05）显著缩短。组间分析发现哮喘患者的呼气末胸壁容积显著更高，主要是由于肺胸廓（RCp；170 ml， = 0.002）容积显著增加，表明存在动态肺过度充气（DH）。与健康受试者相比，哮喘患者的呼吸困难和腿部用力感觉均显著更强烈（ < 0.0001）。除了哮喘患者的RCp和腹部（AB）腔室之间存在更高的胸腹不同步（ < 0.005）外，还分别通过RCp（ < 0.0001）和AB（ = 0.0002）更高的呼气矛盾时间观察到吸气胸廓和膈肌的吸气后动作。我们的数据表明，无运动诱发支气管收缩的哮喘患者在轻度运动期间采用了不同的呼吸模式，并且这一特征与DH和胸腹不同步相关，对运动受限有显著影响。
