Optimal Vancomycin AUC Target in Pediatric MRSA Bacteremia: A Bayesian-guided Approach

The optimal vancomycin area under the concentration-time curve (AUC) target for pediatric methicillin-resistant Staphylococcus aures (MRSA) bacteremia remains unclear. This study aimed to determine the optimal AUC target using Bayesian software.

A retrospective analysis was conducted on patients 3 months to 18 years of age diagnosed with MRSA bacteremia at Asan Medical Center Children`s Hospital between September 2013 and December 2021. The vancomycin AUC was estimated using Bayesian software, and the relationship between AUC 24-48 and outcomes, including persistent bacteremia ≥48 hours, acute kidney injury (AKI), 30-day all-cause mortality and recurrence, was analyzed.

Fifty-six cases were included, with a median age of 2.4 years. Most cases were healthcare-associated infections (96.4%) and occurred in patients with underlying conditions (92.9%). Persistent bacteremia, recurrent bacteremia, 30-day all-cause mortality and AKI were observed in 17.9%, 14.8%, 3.7% and 7.1%, respectively. Although an AUC 24-48 ≥400 mg·h/L did not demonstrate clinical benefit, the receiver operating characteristic curve analysis identified 530 mg·h/L as the appropriate AUC 24-48 threshold for predicting persistent bacteremia and AKI. Persistent bacteremia and AKI were more frequent in patients with AUC 24-48 >530 mg·h/L (62.5% vs. 10.4%, P < 0.01; 37.5% vs. 2.1%, P < 0.01). No significant differences in 30-day mortality or recurrence were observed between the groups with AUC 24-48 above and below this threshold.

AUC 24-48 ≤530 mg·h/L was associated with reduced persistent bacteremia and AKI in pediatric MRSA bacteremia, without significant disadvantages in mortality and recurrence. Future research should explore the lower limit of AUC targets to optimize vancomycin therapy in pediatric patients.