Objectives: To describe antibiotic prescribing practices during the first 2 days of mechanical ventilation among previously healthy young children with respiratory syncytial virus-associated lower respiratory tract infection and evaluate associations between the prescription of antibiotics at onset of mechanical ventilation with clinical outcomes. Design: Retrospective cohort study. Setting: Forty-six children's hospitals in the United States. Patients: Children less than 2 years old discharged between 2012 and 2016 with an International Classification of Diseases diagnosis of respiratory syncytial virus-associated lower respiratory tract infection, no identified comorbid conditions, and receipt of mechanical ventilation. Interventions: Antibiotic prescription during the first 2 days of mechanical ventilation. Measurements and Main Results: We compared duration of mechanical ventilation and hospital length of stay between children prescribed antibiotics on both of the first 2 days of mechanical ventilation and children not prescribed antibiotics during the first 2 days of mechanical ventilation. We included 2,107 PICU children with respiratory syncytial virus-associated lower respiratory tract infection (60% male, median age of 1 mo [interquartile range, 1-4 mo]). The overall proportion of antibiotic prescription on both of the first 2 days of mechanical ventilation was 82%, decreasing over the study period (p = 0.004) and varying from 36% to 100% across centers. In the bivariate analysis, antibiotic prescription was associated with a shorter duration of mechanical ventilation (6 d [4-9 d] vs 8 d [6-11 d]; p < 0.001) and a shorter hospital length of stay (11 d [8-16 d] vs 13 d [10-18 d]; p < 0.001). After adjustment for center, demographics, and vasoactive medication prescription, antibiotic prescription was associated with a 1.21-day shorter duration of mechanical ventilation and a 2.07-day shorter length of stay. Ultimately, 95% of children were prescribed antibiotics sometime during hospitalization, but timing, duration, and antibiotic choice varied markedly. Conclusions: Although highly variable across centers and decreasing over time, the practice of instituting antibiotics after intubation in young children with respiratory syncytial virus-associated lower respiratory tract infection was associated with a shortened clinical course after adjustment for the limited available covariates. A prudent approach to identify and optimally treat bacterial coinfection is needed.
