Hyperpnea-induced changes in parenchymal lung mechanics in normal subjects and in asthmatics.

摘要: The effects of hyperpnea on parenchymal lung mechanics are unknown, but they may contribute to the resultant airflow limitation commonly seen in asthma. To investigate these effects, we measured following parameters seven asthmatic and six normal subjects before after 5 min hyperpnea: specific conductance, upstream resistance, static compliance, coefficient retraction, volumes, hysteresis, ratio maximal partial flow rates (the M:P ratio, an indicator effect deep inhalation airflow, a measure relative airway hysteresis). In addition central airways, as shown by significant falls asthmatics, not subjects, resulted increases residual volume pressure-volume suggestive changes mechanics. also increased consistent with greater than hystere...