[Risk factors for mucus plug formation in pediatric adenovirus pneumonia and construction of a predictive model]

Objective: To identify risk factors for mucus plug formation and to construct a nomogram-based predictive model in children with adenovirus pneumonia. Methods: In this retrospective cohort study, 149 pediatric patients diagnosed with adenovirus pneumonia were included. All patients underwent bronchoscopy at the Department of Respiratory Tianjin Children's Hospital Machang District, between January and December 2024. Their demographic characteristics, clinical manifestations, laboratory findings, imaging features, and treatment details were analyzed.The information of patients were collected about clinical manifestations, laboratory findings, imaging features, and treatment information. Patients were divided into a mucus plug group and a non-mucus plug group based on bronchoscopic findings. Independent risk factors were determined using multivariable Logistic regression. And a predictive nomogram was subsequently developed. Model performance was evaluated using the area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test. Results: Of the 149 enrolled patients (84 boys, 65 girls), 49 cases were classified into the mucus plug group and 100 cases into the non-mucus plug group. Compared with their counterparts, children in the mucus plug group were older on admission (P<0.05), more likely to have a recent history of lower respiratory tract infection, and exhibited a higher prevalence of consolidation or bronchiolitis patterns on chest imaging (all P<0.05), while preoperative corticosteroid use was less frequent (P<0.05). Multivariable Logistic regression identified age on admission (OR=1.14, 95%CI 1.01-1.29, P=0.031), lower respiratory tract infection (OR=5.23, 95%CI 2.15-13.56, P<0.001), radiographic consolidation (OR=2.64, 95%CI 1.10-6.61, P=0.032), and bronchiolitis pattern (OR=2.39, 95%CI 1.04-5.60, P=0.042) as independent risk factors, whereas pre-bronchoscopy corticosteroid use was a protective factor (OR=0.26, 95%CI 0.10-0.63, P=0.004). The nomogram predictive model demonstrated strong discriminative ability (area under the curve=0.83) and good calibration (Hosmer-Lemeshow P=0.358). Conclusions: The independent risk factors for mucus plug formation include older age, a recent history of lower respiratory tract infection, and chest imaging features of consolidation or bronchiolitis in pediatric adenovirus pneumonia. Pre-bronchoscopy corticosteroid therapy is a protective effect. The developed nomogram demonstrates favorable predictive performance and may facilitate early identification and timely intervention.