Evaluation of an Empiric Vancomycin Dosing Protocol on Goal Troughs and Acute Kidney Injury in a Neonatal Intensive Care Unit

Objective: Review the efficacy and safety of an updated empiric vancomycin dosing protocol in a neonatal intensive care unit (NICU).

Methods: Retrospective chart review including neonates with postmenstrual age (PMA) less than 40 weeks without renal dysfunction who received vancomycin per protocol at a single institution's NICU before and after implementation of an updated dosing protocol. The primary outcome is the proportion of initial therapeutic troughs. Secondary outcomes include average trough, achievement of a therapeutic trough, number of days before attainment of a therapeutic trough, and proportion of acute kidney injury (AKI) during therapy.

Results: The 2 groups were similar in gestational age, race, birth weight, PMA, and weight at time of vancomycin initiation. The post-implementation group had a higher proportion of initial therapeutic troughs (33.0% vs 55.1%) and a lower proportion of a subtherapeutic (58.7% vs 43.8%) and supratherapeutic (8.3% vs 1.1%) initial troughs (p = 0.002). The median trough was not different (9.20 vs 10.50 mg/L; p = 0.092). There was no difference in the proportions of achieving a therapeutic trough throughout therapy (69% vs 76%; p = 0.235); however, the post-implementation group achieved a therapeutic trough 1 day earlier (3 vs 2 days; p < 0.001). There was no difference in proportions of AKI developing between the pre-implementation vs post-implementation groups (10.1% vs 5.6%; p = 0.251).

Conclusions: Implementation of an updated vancomycin dosing protocol yielded a higher percentage of initial therapeutic vancomycin troughs and patients reached the therapeutic range 1 day earlier without increasing the proportion of AKI.