Factors associated with pulmonary embolism in children with severe Mycoplasma pneumoniae pneumonia

Background To investigate the clinical characteristics and factors for pulmonary embolism (PE) in children with severe Mycoplasma pneumoniae pneumonia (SMPP). Methods This retrospective study included pediatric patients with SMPP hospitalized at the Affiliated Children’s Hospital of Shandong University between October 2019 and March 2025. They were divided into the PE and control groups based on the presence/absence of PE. Multivariable logistic regression analysis was performed to identify factors independently associated with PE in children with SMPP. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated to evaluate the discriminative ability of the identified factors. Results Among the 199 children with SMPP included in this study, 100 were diagnosed with PE and 99 served as controls. The mean age was 6.73 ± 1.79 years in the PE group and 6.57 ± 1.70 years in the control group. The mean interval from symptom onset to PE diagnosis was 17 days. The multivariable logistic regression analysis indicated that duration of fever (OR = 1.122, 95%CI: 1.040-1.211, P = 0.003), extrapulmonary symptoms (OR = 3.479, 95%CI: 1.853-6.535, P<0.001), NEU (OR = 1.355, 95%CI: 1.131-1.624, P = 0.001), ESR (OR = 1.024, 95%CI: 1.003-1.047, P = 0.028), APTT (OR = 0.926, 95%CI: 0.866-0.990, P = 0.025), D-dimer level (OR = 1.210, 95%CI: 1.111-1.319, P<0.001), and cardiovascular complications (OR = 9.500, 95%CI: 1.759-51.316, P = 0.009) were independently associated with PE in children with SMPP. D-dimer showed the largest AUC (AUC = 0.806), with a sensitivity of 75% and a specificity of 74%. Conclusion Early clinical signs of pulmonary embolism (PE) in children with SMPP include nonspecific prolonged fever, elevated inflammatory markers, increased D-dimer, and cardiovascular complications.