Clinical significance of changes in maximal expiratory flow in 50 ％ and 25 ％ vita l capacity before and after bronchodilator reversibility testing in asthmatics / 中华全科医师杂志

ABSTRACT

To explore the clinical significance of changes in maximal expiratory flow in 50％ and 25％ vital capacity (Vmax50％ & Vmax25％) before and after bronchodilator reversibility testing in patients with asthma.Forced expiratory volume in one second (FEV1),Vmax50％ and Vmax25％ were measured before and after bronchodilator reversibility testing in 118 patients with asthma and 82 with chronic obstructive pulmonary disease (COPD).The rate of positive reversibility in Vmax50％ was significantly higher than that in FEV1 in 118 asthmatics (x2 =7.995,P =0.007).The rates of positive reversibility in Vmax50％ and Vmax25％ were significantly higher in asthmatics than those in COPD patients (x2 =9.335,P =0.009).