A27-15 Lung Ultrasound and Biomarkers as Predictors of Severity in Pediatric Mycoplasma Pneumoniae Pneumonia: A Retrospective Cohort Study in a Tertiary Care Hospital

Background Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) in children, presenting a wide clinical spectrum that can range from mild respiratory illness to severe pneumonia requiring intensive care. Despite its global relevance, few studies in Latin America have characterized its clinical and paraclinical features. This study aimed to describe the clinical presentation and to identify independent predictors of severity using biomarkers and lung ultrasound (LUS) in pediatric patients hospitalized with M. pneumoniae pneumonia in a tertiary care hospital in Bogotá, Colombia. Methods A retrospective cohort study was conducted including children aged 1 month to 17 years with PCR-confirmed M. pneumoniae pneumonia between January 2024 and December 2024. Clinical, laboratory, and imaging variables were analyzed, including lactate dehydrogenase (LDH), C-reactive protein (CRP), oxygen saturation, and LUS score. The main outcomes were admission to the pediatric intensive care unit (PICU) and the need for respiratory support. Logistic regression was used to identify independent predictors of severity after adjustment for age, sex, and comorbidities. Results Twenty-nine patients were included (median age 60 months; 55.2% male). Thirteen patients (44.8%) required PICU admission, and 23.1% required invasive mechanical ventilation. The most frequent symptoms were cough (93.1%), fever (86.2%), and dyspnea (72.4%). PICU patients had significantly higher CRP (15.3 vs. 3.9 mg/L, p = 0.003), LDH (329 vs. 215 IU/L, p = 0.008), and a greater frequency of pleural effusion (53.8% vs. 6.3%, p = 0.006). Multivariable analysis identified LDH > 300 IU/L (OR 4.1; 95% CI 1.7-9.9), oxygen saturation < 90% (OR 3.8; 95% CI 1.3-11.2), and LUS > 15 points (OR 5.3; 95% CI 1.9-14.8) as independent predictors of severity. LUS correlated positively with LDH levels (ρ = 0.71; p < 0.01). The combination of LUS > 15 and oxygen saturation < 90% identified all cases requiring mechanical ventilation. Conclusion Elevated LDH, hypoxemia, and a LUS > 15 were strongly associated with severe M. pneumoniae pneumonia in children. Lung ultrasound proved to be a valuable, non-invasive, and cost-effective tool for early risk stratification, particularly in settings with limited access to advanced imaging. The integration of LUS and LDH into clinical algorithms could optimize early identification of high-risk patients and guide respiratory management decisions. Larger prospective studies are warranted to validate these findings and establish pediatric reference thresholds for these predictive markers. This abstract is funded by: None