Abstract
BACKGROUND: Severe Mycoplasma pneumoniae pneumonia (SMPP) can be complicated by plastic bronchitis (PB), posing a serious threat to children's health. Early identification of PB is crucial. This study aimed to clarify the clinical characteristics and independent risk factors for PB in children with SMPP, to facilitate early clinical recognition. METHODS: A retrospective analysis was conducted on 115 children diagnosed with SMPP and admitted to Chengdu Women's and Children's Central Hospital between January 2023 and March 2024. Based on bronchoscopy results, patients were divided into a PB group and a non-PB group. Clinical characteristics were compared between the two groups. Binary logistic regression was used to identify independent risk factors and construct a predictive model. The predictive performance was evaluated using the receiver operating characteristic (ROC) curve. RESULTS: In children of the PB group, fever duration, peak fever, neutrophil percentage (N%), neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and D-dimer levels, as well as the incidence of unilateral lung involvement [computed tomography (CT) findings: consolidation involving >2/3 volume of the unilateral lung, presenting with uniform opacity accompanied by air bronchogram, which may or may not be associated with atelectasis], distal bronchial occlusion, pleural effusion, and the usage rate of doxycycline were all significantly higher than those in the non-PB group (P<0.05). There were no significant differences in gender, age, lung function, or fractional exhaled nitric oxide (FeNO) levels between the two groups (P>0.05). Binary logistic regression indicated that fever duration >6 days, LDH >289 U/L, and unilateral lung involvement were independent risk factors for PB (P<0.05). ROC curve analysis showed that the area under the curve (AUC) for the combined prediction of these three factors was 0.864, with a sensitivity of 86% and a specificity of 78.8%. CONCLUSIONS: This study confirms that fever duration, LDH levels, and unilateral lung involvement serve as independent risk factors for PB complicating SMPP in children. By integrating a multidimensional assessment system encompassing clinical manifestations, laboratory parameters, and imaging characteristics, the established model facilitates early identification of PB risk, providing a critical time window for clinical intervention.