Adequacy of empiric gram-negative coverage for septic patients at an academic medical center.

Background: Gram-negative organisms (GNOs) have increasing resistance rates to levofloxacin at Virginia Commonwealth University Health System (VCUHS), where levofloxacin is the most common agent added to provide double coverage of gram-negative infections. The goal of this study was to determine the adequacy of empiric gram-negative coverage for septic patients at our institution.

Methods: A retrospective review of patients admitted to VCUHS, from January 1, 2014, to December 31, 2014, with a diagnosis of sepsis, severe sepsis, or septic shock and documented infection, was performed to determine the adequacy of various empiric antibiotic combinations.

Results: Of 219 patients who met the inclusion criteria, 56% of patients received monotherapy and 21% of patients received combination therapy (2 antibiotics) covering GNOs. GNOs (84%) were susceptible to piperacillin-tazobactam. When used in combination with cefepime and meropenem, levofloxacin did not increase coverage. However, levofloxacin provided an 8% increase in coverage and gentamicin provided an additional 13% increase in coverage, respectively, when used in combination with piperacillin-tazobactam.

Conclusions: Among septic patients at VCUHS, gentamicin provided increased gram-negative coverage when compared with levofloxacin. Although susceptibility to piperacillin-tazobactam alone was relatively low, the combination of piperacillin-tazobactam and gentamicin provided nearly equivalent coverage to meropenem and gentamicin.