Background: Patients admitted to the Paediatric Intensive Care Unit (PICU) constitute a high-risk group with a heightened likelihood of receiving inappropriate antimicrobial prescriptions. This study describes an Antimicrobial Stewardship Programme (ASP) in the PICU of a tertiary hospital in Italy.

Method: A pre-post quasi experimental study was conducted between 01/01/2019 and 31/12/2022 in the PICU of the Department for Women's and Children's Health, University Hospital of Padua. The ASP intervention started in February 2021 by a multidisciplinary team using the "handshake" approach. The population included all patients admitted to the PICU. The primary outcome was antibiotic consumption measured as days of therapy administered (DOTs)/1000 patient-days. An interrupted time series analysis was used to assess the trend in antibiotic prescribing before and after the intervention.

Results: 616 patients (episodes) were admitted in the pre-intervention phase (Jan 2019 - Jan 2021) and 602 patients in the post-intervention phase (Feb 2021 - Dec 2022). For overall antibiotic consumption, the ASP implementation resulted in a significant monthly decrease of 3.0% (p< 0.0001). Monthly reductions for higher consumption antibiotics were: meropenem 4.9% (p=0.009), glycopeptides 3.8% (p=0.014), piperacillin-tazobactam 4.8% (p=0.034). The consumption of third-generation cephalosporins and amikacin did not significantly vary.

Conclusions: The ASP intervention was effective in reducing the consumption of antimicrobials in such a complex setting. These results show the importance of antimicrobial stewardship in the scenario of critically ill children.