Outcomes of a paediatric antimicrobial stewardship program in the Emergency Department observation unit of a hospital in Spain.

Background: In paediatric emergency departments the use of empirical antimicrobials is very common, even though most infections are caused by viruses, resulting in misuse of antimicrobials. We aimed to assess the impact of a comprehensive antimicrobial stewardship program (ASP) on the optimisation of antimicrobial prescribing and clinical outcomes in a paediatric Emergency Department Observation Unit (EDOU).

Methods: A quasi-experimental before-and-after longitudinal study was conducted at the EDOU of a paediatric hospital, over 24 quarters from January 2017 to December 2023, excluding 2020 due to the pandemic and the phase-in period. The ASP intervention included the development and implementation of clinical guidelines, rapid diagnostic tests (RDTs), and staff stabilisation. Data on antimicrobial use and clinical outcomes, such as revisits within 72 h and hospital admissions, were collected and analysed using Bayesian structural time series models.

Results: The study included 33,799 patients transferred to the EDOU. Mean antimicrobial consumption significantly decreased from 46.5 ± 12.9 pre-intervention defined daily doses (DDDs) per 100 patients transferred to the Observation Unit (TOs) to 20.1 ± 3.0 DDDs per 100 TOs in the intervention period (p < 0.0001). Significant reductions were observed for amoxicillin-clavulanic acid, amoxicillin, and azithromycin. The percentage of revisits and hospital admissions remained stable for the whole period.

Conclusion: The implementation of ASP measures improved antimicrobial prescribing in the paediatric EDOU. These findings support the need for continued efforts in ASP, emphasising the development and implementation of guidelines, RDTs, and staff stabilisation.