%0 Journal Article %A Maria Clara Góes %A Raul Felipe %A Rêncio Bento Florêncio %A Illia Lima %A Lucien Gualdi %A Andrea Aliverti %A Guilherme Fregonezi %T Effects of thixotropic maneuvers on breathing pattern and chest wall operational volumes in healthy subjects %D 2014 %J European Respiratory Journal %P P3532 %V 44 %N Suppl 58 %X Respiratory muscle fibers stiffness can be temporarily reduced (Thixotropy effect) by contraction at an inflated or deflated lung volume and the stiffness returned during a resting interval (Homma et al.). The magnitude of fibers stiffness can influence the volume of chest wall and the breathing pattern. The objective of this study was to assess the effects of thixotropic maneuvers on chest wall volumes on healthy subjects. We evaluated 20 healthy subjects (23.8 ± 3.1 y) with normal lung function values by Optoeletronic Pletismography during 7 breaths after apneic, inspiratory (ThixIns) and expiratory (ThixEx) thixotropic maneuvers performed at total lung capacity (TLC) and residual volume (RV). Tidal volume showed significant decreasing trend (decreasing ΔVt) for all maneuvers performed at TLC (figure) (p<0.005). End-expiratory volume (EEV) values were significantly higher when we compared breath 1 to breaths 2-7 for all three maneuvers performed from RV (figure) (p<0.0001). Inspiratory time was significantly higher after apnea and inspiratory contraction from TLC (p<0.05) while the only difference from RV was found when we applied the apnea maneuver (p=0.015).Acute effects of Thixotropy respiratory maneuvers (Apnea, Inspiratory and expiratory) performed from RV showed decreased EEV and increased tidal volume. %U