Antimicrobial de-escalation strategies in hospitalized patients with pneumonia, intra-abdominal infections, and bacteremia.

Increasing numbers of serious hospital/healthcare- or community-acquired infections are caused by resistant (often multi-drug resistant) bacterial pathogens. Because delayed or ineffective initial therapy can have severe negative consequences, patients at risk for these types of infections typically receive initial empiric antibiotic therapy with a broad-spectrum regimen covering the most likely pathogens, based on local surveillance data and risk factors for infection with a resistant microorganism. While improving the likelihood of a successful outcome, use of broad-spectrum, often high-dose, empiric antimicrobial therapy also creates pressure for the selection or development of resistant microorganisms, as well as increasing costs and possibly exposing patients to adverse events or collateral damage such as Clostridium difficile-associated disease. De-escalation is a strategy that attempts to balance the competing aims of providing initial empiric therapy that is appropriate and covers the likely pathogens, and limiting antimicrobial exposure and increased risk for emergence of resistant pathogens. More specifically, the de-escalation strategy involves collection of cultures for later microbiological assessment before initiating broad-spectrum empiric therapy covering the most likely pathogens, with the intention of streamlining or de-escalating to a more narrow-spectrum antimicrobial regimen 2-3 days later if warranted by clinical status and culture results. In some cases, negative culture results and subsequent clinical review may allow for termination of initial empiric therapy. In this manner, de-escalation enables more effective targeting of the causative pathogen(s), elimination of redundant therapy, a decrease in antimicrobial pressure for emergence of resistance, and cost savings. This article examines application of the de-escalation strategy to 3 case patients, one with healthcare-associated pneumonia, another with complicated intra-abdominal infection, and a third with central line-associated bacteremia.