目的　探讨毛细支气管炎患儿测定单次潮气肺功能的临床意义。方法　检测和比较住院且<1岁的756例初次喘息毛细支气管炎患儿和115例支气管肺炎患儿的单次潮气肺功能。部分达峰时间比≤第20百分位和≥第80百分位的毛细支气管炎患儿出院1年后电话随访其喘息情况。结果　毛细支气管炎患儿与支气管肺炎患儿比较，达峰时间比，达峰容积比，吸气时间，吸呼比，呼出25%、50%潮气容积时的呼气流速的差异有统计学意义(P均<0.05)。达峰时间比≤第20百分位的毛细支气管炎患儿1年内再喘息的比例为37.5%；达峰时间比≥第80百分位的毛细支气管炎患儿1年内再喘息比例为11.3%，两组差异有统计学意义(P<0.05)。结论　单次潮气肺功能测定提示，阻塞程度较重的毛细支气管炎患儿再次喘息的可能性较大。

Objective　To study clinical significance of single tidal breathing testing in bronchiolitis. Methods Infants with bronchiolitis at first wheezing (bronchiolitis group, n=756), and 115 infants with bronchopneumonia (bronchopneumonia group) hospitalized were enrolled. Tidal breathing parameters were analyzed in two groups. Bronchiolitis group was divided according to percentiles of the fraction of exhaled time at peak tidal expiratory flow to total expiratory time (TPTEF/TE). The episodes of recurrent wheezing of infants below the 20th or above the 80th percentile of TPTEF/TE were followed up by phone calls within 1 year after discharge from the hospital. Results There were significant differences in TPTEF/TE, VPEF/VE, Ti, Ti/Te, TEF75 and TEF50 between bronchiolitis group and bronchopneumonia group. The recurrent wheezing rate of infants with bronchiolitis below the 20th percentile of TPTEF/TE was significantly higher than that above the 80th percentile of TPTEF/TE (37.5% vs 11.3%). Conclusions There is the greater possibility of recurrent wheezing in the infants with the more serious airway obstruction reflected by single tidal breathing testing in bronchiolitis.