Impact of antimicrobial stewardship interventions on appropriateness of surgical antibiotic prophylaxis. How to improve

Background and Objectives: Surgical Site Infections (SSIs) are the most common healthcare-associated infections and represent a major clinical problem in terms of mortality, morbidity, length of stay and overall costs. The appropriateness of Surgical Antibiotic Prophylaxis (SAP) is a key component to reduce the SSIs while the inappropriateness is a major cause of some emerging infections and selection of antibiotic resistance, therefore increasing healthcare costs. For this reasons international and national guidelines have been developed to guide clinicians in the optimal use of SAP. The The overall compliance to these guidelines is poor, with a high heterogeneity and as a consequence there is no universally recognized intervention to improve the appropriateness of SAP. The antimicrobial stewardship program is a systematic approach to improve appropriateness of antimicrobial use, to optimize the treatment of infections and to minimize the adverse effects associated with antibiotic use, like antimicrobial resistance, toxicity and costs. We describe a successfully Antimicrobial Stewardship (AMS) intervention on SAP appropriateness. Material and Methods: The prospective study was conducted at “Santa Maria” tertiary hospital in Terni, Umbria, in 12 main surgical units and was organized in three subsequent phases . The hospital defined evidence-based guidelines for optimal use of SAP, approved a new workflow to optimize the process of ordering, dispensing, administering and documenting SAP and created a satellite pharmacy in the operative block . Phase 1: we analysed 2059 elective surgical cases from January to June 2018 for 3 SAP parameters of appropriateness: indication, choice, dose. Phase 2: in July 2018 an audit was performed to analyse the result ; we reviewed 1781 elective surgical procedures from July to December 2018 looking for the same 3 SAP parameters of appropriateness. Results: The comparative analysis between phase 1 and 2 has demonstrated that the correct indication has a significant improvement (p-value 0.00128), moving from 73.63% in phase 1 to 77.82% in phase 2. The choice of antibiotic has not shown any significant improvement (p-value 0.4863) . The correct dose significantly improved (p-value< 2.2 1016 ), rising from 71.75% in phase 1 to 86.19% in phase 2. The overall compliance had a significant improvement (p-value <5.6 1012) passing from 40.21% in tphase 1 to 51.15% in phase 2. Conclusions: Our prospective study demonstrated a model of succesfully antimicrobial stewardship intervention that improves appropriateness of SAP.