P-1231. Optimal vancomycin AUC target in children with MRSA bacteremia: based on Bayesian-guided dosing

Abstract Background Despite the widespread use of vancomycin in methicillin-resistant Staphylococcus aures (MRSA) infections, there is still a lack of clinical data elucidating the optimal target concentration of vancomycin in the pediatric population. Methods From September 2013 to December 2021, a retrospective analysis was conducted on pediatric patients (3 months- 18 years of age) with MRSA bacteremia. Vancomycin area under the concentration-time curve (AUC) was estimated by Bayesian software. Results A total of 56 patients with MRSA bacteremia were included, with median age of 2.4 years. 92.9% had underlying medical conditions, most of which were associated with catheter-associated infections. Persistent bacteremia ≥ 48 hours, recurrent bacteremia, 30-day all-cause mortality, and acute kidney injury (AKI) were observed in 17.9%, 14.8%, 3.7%, and 7.1%, respectively. AUC24-48 ≥ 400 did not demonstrate clinical benefit in the above outcomes. Persistent bacteremia was associated with source control, 30-day all-cause mortality, and AKI. As an AUC target, AUC24-48 ≥ 528.2 mg·h/L was associated with persistent bacteremia (P < 0.01), and AUC24-48 ≥ 536.8 mg·h/L was associated with AKI (P = 0.01). No significant factors associated with 30-day mortality and recurrence were identified. Conclusion We suggest an AUC24-48 < 528.2 mg·h/L as the optimal target for children aged ≥ 3 months with MRSA bacteremia. The lower bound of the target range was not identified. Disclosures All Authors: No reported disclosures