Mitigating Risk of Acute Kidney Injury Among Children With Methicillin-resistant Staphylococcus aureus Osteomyelitis.

Objective: Children with acute hematogenous osteomyelitis (AHO) from methicillin-resistant Staphylococcus aureus (MRSA) are treated with vancomycin despite the risk of acute kidney injury (AKI). This study evaluates the rate of AKI and resource utilization for children with or without AKI when vancomycin is used in this setting.

Methods: Children with MRSA AHO treated with vancomycin were retrospectively studied. AKI was assessed by clinical diagnosis and Kidney Disease Improving Global Outcomes (KDIGO) criteria. Cohorts of children with or without AKI were compared for differences in treatment, resource utilization, and outcomes. Multivariate logistic regression analysis assessed factors associated with risk for AKI. Cost analysis was performed using the Pediatric Health Information System and Healthcare Cost and Utilization Project databases.

Results: Among 85 children studied, 14 (16.5%) had chart-diagnosed AKI and 24 (28.2%) met KDIGO criteria. Children with AKI had more febrile days and higher thrombosis rates. They had longer vancomycin treatment (8 vs 5 d), higher troughs (27.8 vs 17.5 mg/L), and prolonged hospitalization (19.9 vs 11.1 d). Multivariate analysis found a maximum vancomycin trough level (odds ratio: 1.05, P = 0.003) with a cutoff of 21.7 mg/L predicted AKI.Only 2 of 20 (10%) children who had MRSA isolates with a minimum inhibitory concentration of 2 achieved therapeutic vancomycin levels. Pediatric Health Information System data of 3133 children with AHO treated with vancomycin identified 75 (2.4%) with AKI who had significantly longer lengths of stay (13 vs 7 d) and higher billed charges ($117K vs $51K) than children without AKI.

Conclusions: Chart documentation of AKI (16.5%) grossly underestimated KDIGO-defined occurrence (28.2%). This study showed that vancomycin-associated AKI required substantially greater resource utilization and higher health care costs. Lowering the targeted trough range, shortening the duration of vancomycin therapy, and considering alternative antibiotics when minimum inhibitory concentration ≥2 will reduce the risk and cost of AKI among children with MRSA AHO.

Level of evidence: Level III-retrospective comparative therapeutic study.