Continuous infusion OPAT via elastomeric pumps: effectiveness, safety, and cost-saving potential in a real-world Italian cohort

Purpose: To evaluate clinical outcomes, safety, patient-reported satisfaction, and cost-effectiveness of elastomeric pump-based Outpatient Parenteral Antimicrobial Therapy (OPAT) over six years at an Italian tertiary center. Methods: This retrospective single-center study included 76 adult patients treated with continuous-infusion OPAT via elastomeric pumps between 2019 and 2024 at the University Hospital of Trieste, Italy. Results: A total of 1,934 elastomeric pump-based OPAT days were delivered (median duration of 22.9 days). Clinical cure was achieved in 85.5% of patients; recurrence and failure occurred in 6.2% and 7.9%, respectively. Most frequent indications were skin/soft tissue and surgical site infections (25.9%), complicated urinary tract infections (22.4%), and bone/joint infections (16.4%). Pathogens were mainly Gram-negative (70.7%), including Enterobacterales (40.2%, 57.6% ESBL-producing), Pseudomonas aeruginosa (26.8%), and Staphylococcus aureus (17.1%, 28.6% methicillin-resistant S. aureus). The most used antibiotics were piperacillin/tazobactam (51.3%), cefepime (12.5%) and ceftolozane/tazobactam (7.5%). Adverse events were observed in 13.75% of treatments, primarily vascular access-related (5.7 events/1,000 OPAT-days); drug-related adverse events occurred in 7.8% of patients (3.1 events/1,000 OPAT-days). Among contacted patients (75% response rate), 83.7% expressed willingness to reuse the pump. Total OPAT costs were €62,190.64 compared to an estimated €773,600.00 for inpatient care, yielding a 92% cost reduction (€711,409 saved). Conclusion: Elastomeric pump-based OPAT is a clinically effective, well-tolerated, and economically advantageous option for selected infections. Its integration into stewardship programs supports broader implementation within modern, sustainable infectious disease care models.