Introduction: Piperacillin/tazobactam (P/T) exhibits time-dependent bactericidal activity but due to a short half-life, a prolonged infusion duration may be more efficient at achieving active concentrations.

Hypothesis: Critically ill patients who receive a prolonged infusion of P/T may have better outcomes compared to standard infusions.

Methods: Standard dosing of P/T in a medical/surgical intensive care unit was changed to a 4-hour infusion. Data from 3 months prior and 4 months after the intervention was collected and analyzed.

Results: Patients receiving P/T prolonged infusion, compared to standard infusion, demonstrated a trend towards a shorter ICU length of stay (7.92 vs 5.51 days, p=0.13). Patients were then matched by APACHE II scores, separated into high (>17) and low (<17) scores, and then analyzed according to standard or prolonged infusions. Only critically ill patients with high APACHE II scores demonstrated a significantly shorter LOS with a prolonged, compared to standard, infusion (7.29 vs 3.38 days, p=0.006). Additionally, there was a 1 gm per patient per day savings, which was associated with nearly $12,000 saved per year.

Conclusions: More consistent serum levels may allow more rapid recovery from an infection leading to a shorter ICU length of stay, earlier discharge and significant cost savings.