Characteristics of pulmonary function in children patients with positive bronchodilating response using impulse oscillation system

Abstract

Objective To discuss the characteristics of pulmonary function in children patients with positive bronchodilating response using impulse oscillation system(IOS) and provide the evidence for clinical diagnosis and performing IOS.Methods Seventy children patients with bronchodilating response using IOS were recruited randomly for this study.Forty children patients with positive bronchodilating response were regarded as positive group and the other thirty children patients with negative bronchodilating response were regarded as negative group.The IOS parameters,for example,total respiratory impedance (Z5),respiratory resistance at 5 Hz(R5),reactance at 5 Hz(X5),peripheral respiratory resistance(Rp) in the two groups were analyzed.Results Z5,R5,X5 of the positive group [(123.45 ± 24.75)％,(120.09 ± 25.40)％,(138.62 ± 33.48)％] were higher than those of the negative group [(103.89 ± 16.30)％,(102.67 ± 18.16)％,(111.85 ± 14.93)％].There were significantly different between the two groups (P ＜ 0.05).Moreover,Rp ≥ 19.89 cmH2O/ (L·s)(1 cmH2O =0.098 kPa) in the positive group was 50.00％(20/40),which was higher than that in the negative group[23.33％(7/30)].There was significant difference between the two groups(P＜ 0.05).Conclusions The impedance of children patients with positive bronchodilating response using IOS is significantly increased,especially X5.When IOS parameters ≥ 100％,especially X5 ≥ 100％,which suggest that perform the bronchodilation test in order to decrease the rate of missed diagnosis of asthma. Key words: Child; Asthma; Impulse oscillation; Bronchodilation test