Ceftazidime-avibactam in elastomeric pump for vascular graft infection: a case report

Vascular prosthetic infections (VPI) are associated with high morbidity and mortality, often requiring prolonged antimicrobial therapy. The emergence of carbapenem-resistant Enterobacterales (CRE) represents a significant challenge due to the limited availability of outpatient treatment options. While ceftazidime-avibactam is a cornerstone of the treatment of CRE infections, its 12-hour stability limit poses a barrier for standard Outpatient Parenteral Antimicrobial Therapy (OPAT).

We describe a 78-year-old male with multiple comorbidities (diabetes, peripheral artery disease, and ischemic cardiomyopathy) who presented with a VPI following an axillo-femoral bypass. Initial cultures isolated MRSA and ESBL-producing Klebsiella pneumoniae. Despite surgical debridement and various antibiotic regimens, the patient experienced a recurrence with inguinal fistulization. A subsequent isolate of K. pneumoniae demonstrated resistance to both ertapenem and ceftolozane-tazobactam.Treatment was transitioned to daptomycin (500 mg daily) and ceftazidime-avibactam (2.5 g three times a day), with oral rifampin added for anti-biofilm activity.To facilitate early discharge per the patient's request, ceftazidime-avibactam was administered off-label via an elastomeric pump. A continuous infusion regimen of 5 g every 12 hours was delivered through a PICC line. This schedule addressed the drug's stability constraints while requiring only two daily administrative interventions.The patient completed the OPAT course without adverse events or signs of pyridine-related toxicity. Clinical and microbiological resolution was achieved, and no relapses were detected during the follow-up period.

This case demonstrates that continuous 12-hour infusion of ceftazidime-avibactam via elastomeric pumps is a feasible and safe strategy for managing complex CRE infections in the OPAT setting. Such tailored approaches can enhance patient quality of life and reduce hospital stays, though further prospective studies are needed.