Abstract:

Objective To discuss the characteristics of pulmonary function changes in the pediatric patients with Mycoplasma pneumoniae pneumonia （MPP）， the effect of inhaled corticosteroids during the recovery phase on pulmonary function， and the improvement effects of different aerosolized medications on pulmonary function， and to clarify the significance of inhaled corticosteroids in the treatment of MPP pediatric patients during the recovery phase. Methods A retrospective study was conducted. Sixty-nine MPP children who received inhaled corticosteroids after discharge were selected as treatment group. According to the different medications used after discharge， they were divided into steroid group （receiving inhaled corticosteroids alone， n=42） and combination group （receiving inhaled corticosteroids combined with inhaled long-acting bronchodilators，n=27）. Additionally， 30 children who did not receive aerosol therapy after discharge during the same period were selected as control group. The general data of the pediatric patients in various groups were collected. The pulmonary function parameters， including forced vital capacity （FVC）， forced expiratory volume in the first second （FEV1）， ratio of forced expiratory volume in 1 second to forced vital capacity （FEV1/FVC）， peak expiratory flow （PEF）， and maximal mid-expiratory flow （MMEF）， were detected using pulmonary function equipment at the time of entering the recovery phase and 1 month after entering the recovery phase. The changes in pulmonary function of the pediatric patients between control group and treatment group were analyzed. Results The pulmonary ventilation dysfunction in the MPP pediatric patients was mainly restrictive， followed by mixed. The pulmonary function could be normal or only show small airway dysfunction in some children. In both teatment and control groups， the second pulmonary function parameters including FVC， FEV1， PEF， maximal expiratory flow at 25% of forced vital capacity（MEF25）， maximal expiratory flow at 50% of forced vital capacity（MEF50）， maximal expiratory flow at 75% of forced vital capacity（MEF75）， and MMEF of the pediatric patients were significantly increased compared with the first measurement （P<0.05）. Compared with control group， the increase in FEV1/VC at the second measurement of the pediatric patients in treatment group was not significant （P>0.05）. The differences in pulmonary function parameters showed an increasing trend in treatment group and control group. The differences in MEF25 and MMEF of the pediatric patients in the treatment group were higher than those in control group （P<0.05）. The differences in pulmonary function parameters of the pediatic patients in both steroid group and the combination group showed an overall increasing trend. The differences in FVC， FEV1， FEV1/VC， MEF25， MEF50， and MMEF of the pediatric patients in steroid group were slightly higher than those in combination group. Compared with steroid group， the differences in PEF and MEF75 of the pediatric patients in combination group were slightly higher， but the differences were not statistically significant （P>0.05）. The differences in MEF25， MEF50， and MMEF of the pediatric patients in steroid group were higher than those in control group （P<0.05）. Conclusion Both large and small airway functions can be affected in the pediatric patients with MPP， with restrictive ventilation dysfunction being predominant. Airway function can improve during the disease recovery phase. Inhaled corticosteroids during the recovery phase may have a positive therapeutic significance in promoting the recovery of pulmonary function， especially small airway function. The bronchodilators showed no significant effect on improving the pulmonary function during the recovery phase. Therefore， inhaled corticosteroids alone during the recovery phase may promote the recovery of pulmonary function in children with MPP.

Key words: Mycoplasma pneumoniae paneumonia, Pulmonary function, Child, Glucocorticoids, Vital capacity