SERPINC1 and respiratory syncytial virus bronchiolitis: At the optimal threshold of 0.154, the model achieved sensitivity of 75.0%, specificity of 90.5%, and overall accuracy of 88.8%.<h4>Conclusions</h4>We developed and internally validated a prediction model incorporating fungal co-infection, admission glucose, antithrombin III, and interleukin-6 for early identification of septic shock risk in pediatric RSV bronchiolitis patients.