Intervention: The training group (part 2) performed three series of 15 contractions against an expiratory resistance (60% maximum expiratory pressure [PEmax]) two times a day, whereas the control group performed breathing exercises to enhance maximal inspirations.
An increase in maximum expiratory flow and a decrease in expiratory time indicated increased lung recoil in these rats.
We evaluated the MV and weaning time, maximum inspiratory pressure, maximum expiratory pressure, vital capacity, respiratory frequency to tidal volume ratio (f/Vt), use of noninvasive ventilation (NIV) post extubation, and re-intubation rate.
Expiratory time constant (RCEXP) was measured as the ratio between volume and flow at 75% of maximum expiratory flow and calculated as the product of CSTAT MEAS and RINS.
Main Outcome Measures: Lung volume, peak expiratory flow (PEF), MIP, and maximum expiratory pressure (MEP) were measured by using a spirometry and inspiratory force meter, respectively.
The V'exp slope before the expiratory peak flow and the expiratory volume (Volexp) at 50% and 75% of expiratory time were estimated.
Analysis of expiratory time constant (tau) indicates the time required by the respiratory system to achieve a steady state.
Particles were captured on proximal pieces of the ventilator circuit or directly lost on the expiratory limb during the long expiratory time measured in this study [7, 38].
During acute bronchospastic episodes, patients have an increase in airway resistance and expiratory time constant.
