Vancomycin Dosing for Pneumonia in Critically Ill Trauma Patients

Abstract

Vancomycin has been recommended as the treatment of choice for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia with a desired trough concentration of 15 to 20 mg/L. The purpose of this study was to evaluate the initial dosing of vancomycin for MRSA pneumonia in critically ill adult trauma patients. Critically ill adult trauma patients were retrospectively identified for inclusion into the study. Patients initiated at a dose of 1 g intravenously (i.v.) every 8 hours were compared with patients initiated at a dose of 1 g i.v. every 12 hours. Baseline continuous demographic variables and steady-state vancomycin trough concentrations were compared between the two groups using a Student's t test (alpha = 0.05). There were 36 patients who satisfied criteria for inclusion, 17 patients in the 1 g every 8 hour group and 19 patients in the 1 g every 12 hour group. The mean steady-state trough concentration was higher in the 1 g every 8 hour group versus the 1 g every 12 hour group (11.1 vs. 6.8 mg/L, p = 0.014). A steady-state trough concentration greater than 15 mg/L was achieved in 23.5% of the patients in the 1 g every 8 hour group and none of the patients in the 1 g every 12 hour group. A vancomycin regimen of 1 g i.v. every 12 hours in critically ill trauma patients with MRSA pneumonia and normal renal function is unlikely to achieve trough concentrations of 15 to 20 mg/L. Doses of at least 1 g i.v. every 8 hours are needed.