BACKGROUND: Bronchofiberscopic lavage is a therapeutic treatment for mycoplasma infection. However, there are limited reports on the use of bronchofiberscopic lavage with acetylcysteine instillation. The aim of our study was to investigate the clinical effect of bronchofiberscopic lavage with acetylcysteine instillation on refractory mycoplasma pneumoniae pneumonia in children. METHODS: This was a retrospective study. Clinical and laboratory data were collected from 280 children hospitalized with MPP in the Department of Pulmonary and Critical Care Medicine at Kunming Children's Hospital from January 2021 to January 2023, and these were divided into two groups: the study group and the control group. Children in the control group were treated with anti-infective, antitussive, and antipyretic routine symptomatic treatment and nebulization of acetylcysteine suspension, while children in the study group were treated with bronchofiberscopic lavage with acetylcysteine instillation along with standard treatment as in the control group. The clinical characteristics, adverse reactions, pulmonary imaging changes, and laboratory examination indicators were compared between the two groups. RESULTS: The treatment effective rate and the absorption area of lung lesions in the study group were significantly higher than those in the control group (P <
0.05). Before treatment, there were no statistically significant differences in WBC, IgG, IgE, CRP, and IL-6 levels between the two groups (P >
0.05). After 7 days of treatment, IgG levels in both groups were higher than those before treatment, while WBC, IgE, CRP, and IL-6 levels were lower than those before treatment (P <
0.05). CONCLUSIONS: The bronchofiberscopic lavage with acetylcysteine instillation constitutes a safe and efficacious therapeutic regimen, which might alleviate the clinical symptoms experienced and reduce the levels of inflammatory factors for children with RMPP.