When airway obstruction was severe, PEF, V50, V25 were all lower on time.These changes was relating to small airway obstruction and muscular force.

• 结论肺癌病人肺功能表现可有阻塞性通气功能障碍，当气道阻塞严重时，PEF、V50、V25可同时下降，说明PEF的下降可与小气道的阻塞有关，V50下降也可与用力大小有关。