目的 探讨肺炎支原体肺炎（MPP）婴幼儿肺功能的变化特点。方法 选取2014年1月至2018年6月诊断为MPP的0~36月龄住院患儿196例为研究对象，同期非肺炎支原体感染引起的0~36月龄肺炎患儿208例为对照（非MPP组）。回顾性分析患儿临床资料，比较两组患儿入院次日和出院当日肺功能结果，并随访MPP患儿出院后2周和出院后4周的肺功能。结果 与非MPP组相比，MPP组入院次日和出院当日肺功能检测显示，达峰时间比（TPTEF/TE）、达峰容积比（VPTEF/VE）、吸呼比及呼出75%潮气量时呼气流量显著下降（P < 0.05）；潮气峰流量与呼出75%潮气量时呼气流量比、呼吸频率、有效气道阻力和公斤功能残气量均显著升高（P < 0.05）。与肺功能参数正常参考值比较，MPP和非MPP两组患儿入院次日VPTEF/VE和TPTEF/TE均有所下降；出院当日MPP组患儿VPTEF/VE和TPTEF/TE仍有所下降，而非MPP组患儿已达正常水平。与出院当日比较，MPP组患儿出院后2周及4周VPTEF/VE和TPTEF/TE均升高（P < 0.05），但出院后4周时TPTEF/TE仍未达到正常水平。结论 急性期MPP和非MPP婴幼儿均存在阻塞性通气功能障碍，而MPP患儿的小气道阻塞更加严重，且改善缓慢，恢复期仍存在一定程度气流受限。

Objective To study the changes in pulmonary function in infants and young children with Mycoplasma pneumoniae pneumonia (MPP). Methods A total of 196 hospitalized children (at age of 0-36 months) who were diagnosed with MPP from January 2014 to June 2018 were enrolled as study subjects. A total of 208 children (at age of 0-36 months) with pneumonia not caused by Mycoplasma pneumoniae infection during the same period of time were enrolled as controls (non-MPP group). A retrospective analysis was performed for their clinical data. The two groups were compared in the pulmonary function on the next day after admission and on the day of discharge. The children with MPP were followed up to observe pulmonary function at weeks 2 and 4 after discharge. Results Compared with the non-MPP group, the MPP group had significant reductions in the ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE), ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE), inspiratory-to-expiratory time ratio, and tidal expiratory flow at 25% remaining expiration on the next day after admission and on the day of discharge (P < 0.05). In addition there were significant increases in the ratio of peak tidal expiratory flow to tidal expiratory flow at 25% remaining expiration, respiratory rate, effective airway resistance, and plethysmographic functional residual capacity per kilogram (P < 0.05). Compared with the normal reference values of pulmonary function parameters, both groups had reductions in VPTEF/VE and TPTEF/TE on the next day after admission; on the day of discharge, the MPP group still had reductions in VPTEF/VE and TPTEF/TE, while the non-MPP group had normal values. The MPP group had increases in VPTEF/VE and TPTEF/TE from the day of discharge to weeks 2 and 4 after discharge (P < 0.05), but TPTEF/TE still did not reach the normal value at week 4 after discharge. Conclusions Airway obstruction is observed in infants and young children with acute MPP or non-MPP, and the children with MPP have a higher severity of airway obstruction and a longer time for improvement, with a certain degree of airway limitation in the recovery stage.