Predictors of mortality for methicillin-resistant Staphylococcus aureus health-care-associated pneumonia: Specific evaluation of vancomycin pharmacokinetic indices

Objective: The goal of this investigation was to determine whether vancomycin pharmacokinetic indexes (eg, serum trough concentrations or area under the concentration curve [AUC] values) were associated with mortality for patients with health-care-associated pneumonia (HCAP) attributed to methicillin-resistant Staphylococcus aureus (MRSA). Design: A retrospective, single-center, observational cohort study. Setting: Barnes-Jewish Hospital, a 1,200-bed urban teaching facility. Patients: Adult patients requiring hospitalization who were identified as having HCAP attributed to MRSA by BAL semi-quantitative cultures. Interventions: Retrospective data collection from automated hospital, microbiology, and pharmacy databases. Measurements and main results: One hundred two patients with MRSA HCAP were identified over a 6.5-year period. Thirty-two patients (31.4%) died during their hospitalization. The mean (± SD) vancomycin trough concentrations (13.6 ± 5.9 vs 13.9 ± 6.7 μg/mL, respectively; p = 0.866) and AUC values (351 ± 143 vs 354 ± 109 μg/h/mL, respectively; p = 0.941) did not differ between survivors and nonsurvivors. The stratification of the vancomycin trough concentrations and AUC values yielded no relationship with hospital mortality. Conclusions: We found no evidence that greater vancomycin trough concentrations or AUC values correlated with hospital outcome. Based on these results, aggressive dosing strategies for vancomycin (eg, trough concentrations of > 15 μg/mL) may not offer any advantage over traditional dose targets (range, 5 to 15 μg/mL).