Evaluation of Vancomycin Dosing Targeting Conservative Troughs for Methicillin-Resistant Staphylococcus aureus Bacteremia Jacob Lines, Jessica Burchette, Paul Lewis Johnson City Medical Center - Johnson City, TN
Background/Purpose: Evaluation of treatment failures with conservative trough concentrations compared to conventional trough concentrations.
Methodology: This is a retrospective, institutional review board-approved, cohort study conducted from October 1, 2013 to June 30, 2017. Included participants were greater than 17 years old, admitted with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI), and received vancomycin for greater than or equal to 72 hours with at least 1 appropriately drawn vancomycin trough. Average vancomycin trough concentrations less than or equal to 15mcg/mL were assigned to conservative cohort and greater than 15mcg/mL were assigned to conventional cohort. Treatment failure was defined as 30 day all-cause mortality or persistent BSI greater than or equal to 7 days.
Results: A total of 156 were enrolled, with 96 in the conservative cohort and 60 in the conventional cohort. Baseline characteristics were similar between cohorts with no statistical difference in average initial weight-based dose (p = 0.337). There were 11 failures (6 deaths and 5 persistent BSI) in the conservative and 11 failures (10 deaths and 1 persistent BSI) in the conventional cohort (11.5% vs 18.3%, respectively, p = 0.245). Nephrotoxicity occurred in 2 patients in the conservative cohort and 9 in the conventional cohort (p = 0.009).
Conclusions: Conservative dosing was associated with less nephrotoxicity without an increase in treatment failures for MRSA BSI compared to conventional dosing. Further investigation is warranted to determine the relationship between conservative dosing and persistent BSI.
Presentation Objective: Compare vancomycin dosing targeting conservative trough concentrations to conventional trough concentrations for the treatment of methicillin-resistant Staphylococcus aureus bloodstream infections.
Self-Assessment: Compared to guideline-directed vancomycin troughs (15-20 mg/dL), conservative troughs (10-15 mg/dL) were associated with:_x000D_ A) Worse outcomes and no difference in nephrotoxicity _x000D_ B) Worse outcomes and less nephrotoxicity_x000D_ C) Similar outcomes and less nephrotoxicity _x000D_ D) Similar outcomes and no difference in nephrotoxicity_x000D_
