目的 分析肺炎支原体坏死性肺炎（MPNP）和细菌性坏死性肺炎（BNP）的临床特征，观察炎性指标变化特点。方法 回顾性分析2016年至2021年收治并诊断为MPNP和BNP的临床资料共72例。结果 MPNP组43例，BNP组29例，前者年龄中位数7.9岁，后者1.9岁（P<0.01）。BNP组出现气促、三凹征和无创呼吸机使用的比例分别为79.3%、37.9%和51.7%，MPNP组分别为37.2%、9.3%和18.6%（P<0.05）。BNP组病原以肺炎链球菌和金黄色葡萄球菌为主，占病例总数76%。BNP组病程3天内C反应蛋白中位数83 mg/L，降钙素原中位数29.9 ng/mL，均高于MPNP组14 mg/L和0.1 ng/mL（P<0.05）。MPNP组在病程4~7天和8~14天中性粒细胞比例中位数分别为78.2%和80.4%，BNP组为65.8%和59.8%（P<0.05）。两组白细胞总数在病程前3天差异无统计学意义（P>0.05）。MPNP组血D-二聚体中位数4.1 mg/L高于BNP组3 mg/L（P<0.05）。MPNP组胸水白细胞以单核细胞为主，BNP组以多核细胞为主，BNP组胸水糖（2±2）mmol/L明显低于MPNP组（6±2）mmol/L（P<0.01）。MPNP组肺部发生空洞坏死的时间为（23.4±10.0）天，BNP组为（10.4±5.7）天（P<0.01）。MPNP组8例可见肺动脉栓塞，支气管镜下7例可见塑型形成，21例遗留有管腔狭窄、闭塞后遗症。BNP组12例出现脓气胸。结论 BNP组在病程前3天C-反应蛋白和降钙素原明显升高；容易发生呼吸困难及脓气胸。MPNP组中性粒细胞比例在病程4天以后明显升高，血D-二聚体水平较高，肺部空洞坏死发生晚，容易发生肺动脉栓塞，支气管镜下可见塑型，管腔狭窄、闭塞后遗症发生率较高。

Objective To analyze the clinical features of Mycoplasma pneumoniae necrotizing pneumonia (MPNP) and bacterial necrotizing pneumonia (BNP) and to observe the changes of inflammatory indicators. Methods The clinical data of 72 children diagnosed with MPNP or BNP from 2016 to 2021 were retrospectively analyzed. Results There were 43 children in MPNP group and 29 children in BNP group. The median age was 7.9 years in MPNP group and 1.9 years in BNP group (P<0.01). In the BNP group, the rates of shortness of breath, triple concave sign, and non-invasive ventilator use were 79.3%, 37.9%, and 51.7%, respectively, whereas in the MPNP group, the rates were 37.2%, 9.3%, and 18.6% (P<0.05). Streptococcus pneumoniae and Staphylococcus aureus were the predominant pathogens in the BNP group, making up 76% of all cases. The median C-reactive protein and procalcitonin levels in the BNP group within 3 days of disease course were 83 mg/L and 29.9 ng/mL respectively, which were higher than those in the MPNP group (14 mg/L and 0.1 ng/mL) (P<0.05). At days 4-7 and 8-14 of disease course, the median neutrophil ratio in MPNP group was 78.2% and 80.4%, while that in BNP group was 65.8% and 59.8% (P<0.05). There was no significant difference in the total number of white blood cells between the two groups at days 1-3 of disease course (P>0.05). The median blood D-dimer concentration in the MPNP group was 4.1 mg/L, which was higher than that in the BNP group (3 mg/L) (P<0.05). The pleural fluid leukocytes in MPNP group were mainly mononuclear cells, while those in the BNP group were mainly multinucleated cells. The glucose level of pleural fluid in BNP group was (2±2) mmol/L, which was significantly lower than that in the MPNP group [(6±2) mmol/L, P<0.01)]. The time of pulmonary cavity necrosis in MPNP group was (23.4±10.0) days, while that in BNP group was (10.4±5.7) days (P<0.01). In MPNP group, pulmonary embolism was observed in 8 cases, bronchoscopic plastic formation was observed in 7 cases, and sequelae (lumen stenosis and occlusion) were observed in 21 cases. Pyopneumothorax occurred in 12 cases of BNP group. Conclusions In BNP group, C-reactive protein and procalcitonin increased significantly at days 1-3 of disease course. The children in BNP group were prone to dyspnea and pyopneumothorax. In MPNP group, the proportion of neutrophil increased significantly after 4 days of disease course, the level of D-dimer in blood was higher, the occurrence of pulmonary cavity necrosis was late, and pulmonary embolism was easy to occur, and the plastic formation could be seen under bronchoscopy, and the incidence of sequelae of lumen stenosis and occlusion was high.