Efficacy of Adding Intravenous Methylprednisolone to Nebulized Budesonide in RSV Pneumonia: Modification by Bacterial Co-Infection – A Retrospective Cohort Study

Can Guo, Tingyao Guo, Wenjuan Chen, Guojing Guo Department of Pediatrics, Fuqing City Hospital of Fujian, Fuqing, Fujian, People’s Republic of ChinaCorrespondence: Can Guo, Email [email protected]: To evaluate the efficacy of intravenous methylprednisolone plus nebulized budesonide (IV+NEB CS) versus nebulized budesonide alone (NEB CS) in infants with RSV pneumonia, and to assess the influence of bacterial co-infection.Methods: This retrospective study included 303 patients (≤ 36 months) with RSV pneumonia. Patients were divided into IV+NEB CS (n=140) and NEB CS (n=163) groups, then stratified by bacterial co-infection and antibiotic use. Primary outcomes were time to cough/fever/wheezing relief, disappearance of pulmonary signs, hospital stay, and glucocorticoid-related adverse events.Results: (1) Wheezing relief was faster in the IV+NEB CS group [2.0 (1.5,4.0) vs 3.0 (2.0,4.0) days, P=0.010], but other outcomes did not differ. (2) Subgroup B (IV+NEB CS without bacterial infection) had the shortest median wheezing relief [2.0 (1.0,3.0) days], pulmonary sign resolution [4.0 (3.0,5.0) days], and hospital stay [4.0 (3.0,5.0) days]. (3) Antibiotic use was independently associated with shorter symptom relief and discharge (all P< 0.001); after adjusting for antibiotics, the main effect of IV+NEB CS was no longer significant for most outcomes. (4) Antibiotics also reduced CRP levels (P=0.002). (5) Adverse event rates did not differ between groups.Conclusion: In non-severe RSV pneumonia, adding intravenous methylprednisolone to nebulized budesonide provides no consistent independent benefit after accounting for antibiotic use. The apparent faster recovery with combination therapy was largely explained by antibiotics. Routine intravenous corticosteroids are not recommended. When bacterial co-infection is suspected, antibiotics should be prioritized.Keywords: respiratory syncytial virus, corticosteroids, lower respiratory tract infection, infants and toddlers, antibiotics