Endobronchial abnormalities and bronchoalveolar lavage findings in children with severe pneumonia and Staphylococcus aureus-positive transnasally suctioned airway secretion cultures: a retrospective study

Background We aimed to describe endobronchial abnormalities and bronchoalveolar lavage fluid (BALF) findings in children with severe pneumonia and Staphylococcus aureus -positive transnasally suctioned airway secretion cultures. Methods This retrospective study included 68 children hospitalized between January 2023 and December 2025. Bronchoscopic and BALF findings were evaluated in 34 children. Exploratory comparisons used nonparametric or categorical tests, with false-discovery-rate correction for 11 BALF comparisons. Results Forty-eight children (70.6%) had at least one additional respiratory pathogen. Respiratory support was required in 34, intensive care admission in 17, and invasive ventilation in 11. The bronchoscopy subgroup was older and required less respiratory support, reflecting clinical selection. Retained secretions or mucus plugs were identified in 24 of 34 children (70.6%), bronchial casts in 10 (29.4%), and mucosal necrosis or necrosis-like changes in 6 (17.6%). Staphylococcus aureus was recovered from BALF culture in 4 of 34 children (11.8%). The median BALF neutrophil proportion was 70.0%. None of the 11 BALF comparisons remained significant after false-discovery-rate correction. Conclusion A spectrum of endobronchial abnormalities was documented in this clinically selected subgroup, and BALF showed predominantly neutrophilic inflammation. The findings do not establish Staphylococcus aureus -specific causation or a therapeutic benefit of bronchoscopy.