Impact of a two step antimicrobial stewardship program in a paediatric haematology and oncology unit.

Objective: To describe the implementation of a multi-step antimicrobial stewardship program in a haemato-oncology and stem cell transplantation program unit. Methods: Pre-post quasi-experimental study with two interrupted time-series analyses, conducted between 01/01/2019 and 31/12/2022 in the Paediatric Haemato-Oncology Unit of the Padua Paediatric Hospital. The interventions were: (1) 02/2020: dissemination of febrile neutropenia clinical pathways, (2) April 2021: provision of the clinical pathways via a customized App (Firstline.org) and implementation of a twice-a-week prospective audit and feedback. The main outcome was antibiotic consumption measured by days of administered therapy (DOTs)/1000 patients' days for all antibiotics and most used molecules.

Results: The first intervention (clinical pathways) resulted in a decrease in the overall antibiotic use by the haemato-oncology unit, with an abrupt reduction of 3-gen cephalosporins in favor of piperacillin-tazobactam, as indicated by the clinical pathways. Meropenem and glycopeptide use did not vary. The second intervention (antimicrobial stewardship) further decreased total antibiotic consumption, and a significant decline in meropenem, amikacin, and glycopeptides was achieved.

Conclusions: Multi-step stewardship based on guidelines dissemination, multidisciplinary team intervention and collaboration ("handshake" stewardship) was highly effective in optimizing guidelines adherence and reducing overprescriptions in a fragile patient cohort.