Abstract:

Objective　To analyze the pulmonary characteristics of conventional ventilation and impulse oscillometry in children with Mycoplasma infectious lobar pneumonia and the correlation between the two pulmonary function tests，and to explore the characteristics of airway responsiveness in Mycoplasma infectious lobar pneumonia and the influence of different imaging lesions on pulmonary function. Methods　A total of 120 children aged 5-14 years old with Mycoplasma infectious lobar pneumonia hospitalized from January 2018 to December 2019 in the division of Pediatric Pulmonology of Shandong Provincial Hospital Affiliated to Shandong First Medical University，the conventional ventilation and impulse oscillometry were completed during the hospitalization period，according to the different imaging lesions，the children were divided into single lobe group and multiple lobes group，analysis of pulmonary function results and clinical data were analyzed. Results　Among the 120 children，there were 95 cases in single-lobe group and 25 cases in multiple-lobe group. Normal conventional ventilation were 33 cases（27.5%） and abnormal in 87 cases（72.5%）. Among abnormal conventional ventilation the restrictive ventilation dysfunction in 43 cases，two or more of the three small airway indexes were lower than 65% predicted value was in 63 cases. In the 120 cases，impulse oscillometry test showed normal airway resistance in 106 cases（88.3%） and increased airway resistance in 14 cases（11.7%）. Airway resistance indexes are negatively correlated with ventilation indexes. 43 cases of children with FEV1 measured value/expected value<80% completed bronchodilation test，bronchodilation test was positive in 6 cases，and airway resistance was significantly improved in 11 cases. The airway resistance indexes total respiratory impedance（Z5），total airway resistance（R5），and central airway resistance（R20） of the multiple lobes group were lower than that in sigle lobe group，and peripheral elastic resistance（X5） was higher than that in single lobe group，there was no statistical difference. The conventional ventilation index vital capacity（VC），forced vital capacity（FVC），forced expiratory volume in one second（FEV1） of the multiple lobes group was lower than that in single lobe group，have significantly different between the two groups（P<0.05）. Conclusion　The children with Mycoplasma infectious lobar pneumonia mostly have restrictive ventilation dysfunction；the small airway function indexes are significantly damaged and the recovery of small airway indexes is slower than that of large airway indexes；airway resistance indexes have a good negative correlation with the expiratory flow indexes. Mycoplasma pneumoniae infection can induce increased airway responsiveness，and bronchodilation tests in some children show reversible airflow limitation and a significant improvement in airway resistance. Children with lesions involving multiple lobes had more severe reduction in lung volume，and the reduction of expiratory flow indexes was widespread in children with different lesions.

Key words: lobar pneumonia, Mycoplasma pneumoniae, conventional ventilation, impulse oscillometry, pulmonary function, child

摘要： 目的　分析肺炎支原体（Mycoplasma pneumoniae，MP）感染大叶性肺炎患儿常规通气与脉冲振荡肺功能特点及两种肺功能检查指标的相关性，探讨MP感染气道反应性特点及不同影像学病变范围对肺功能的影响。方法　选取2018年1月至2019年12月在山东第一医科大学附属省立医院小儿呼吸科住院的共120例5~14岁MP感染大叶性肺炎患儿为研究对象，住院期间完成常规通气、脉冲振荡肺功能检查，根据影像学病变范围分为单肺叶受累和多肺叶受累，分析肺功能及相关临床资料。结果　120例患儿中单肺叶受累95例、多肺叶受累25例。120例常规通气肺功能正常33例（27.5％），异常87例（72.5％）。常规通气肺功能异常患儿中限制性通气功能障碍43例，小气道功能指标≥2项低于65％预计值者63例。120例脉冲振荡肺功能气道阻力未见异常106例（88.3％）、气道阻力升高14例（11.7％）。脉冲振荡肺功能气道阻力指标与常规通气呼气流量指标呈负相关。43例第1秒用力呼气容积（FEV1）实测值/预计值＜80％患儿支气管舒张试验阳性6例，气道阻力显著改善11例。多肺叶受累患儿气道阻力指标呼吸总阻抗（Z5）、呼吸道总阻力（R5）、中心呼吸道阻力（R20）低于单肺叶受累患儿，周边弹性阻力（X5）高于单肺叶受累患儿，差异均无统计学意义；多肺叶受累患儿常规通气指标肺活量（VC）、用力肺活量（FVC）、第1秒用力呼气容积（FEV1）等肺容量指标均低于单肺叶受累患儿，差异有统计学意义（P＜0.05）。结论　MP感染大叶性肺炎患儿以限制性通气功能障碍为主，小气道功能指标受损显著且较大气道功能指标恢复慢；气道阻力指标与通气指标呈负相关。MP感染可诱发气道反应性增高，部分患儿支气管舒张试验呈可逆性气流受限和呼吸道阻力显著改善表现。病变范围累及多肺叶患儿肺容量降低更严重，呼气流量指标降低在不同病变范围患儿中均广泛存在。

关键词: 大叶性肺炎, 肺炎支原体, 常规通气, 脉冲振荡, 肺功能, 儿童