Empiric antibiotic selection strategies for healthcare‐associated pneumonia, intra‐abdominal infections, and catheter‐associated bacteremia

Abstract

Initial selection and early deployment of appropriate/adequate empiric antimicrobial therapy is critical to minimize the significant morbidity and mortality associated with hospital‐ or healthcare‐associated infections (HAIs). Initial empiric therapy that inadequately covers the pathogen(s) causing a serious HAI has been associated with increased mortality, longer hospital stay, and elevated healthcare costs. Moreover, subsequent modification of initial inadequate therapy, later in the disease process when culture results become available, may not remedy the impact of the initial choice. Because of this, it is important that initial empiric therapy covers the most likely pathogens associated with infection in a particular patient, even if this initial regimen turns out to be unnecessarily broad, based on subsequent culture results. The current paradigm for management of serious HAIs is to initiate empiric therapy with a broad‐spectrum regimen covering likely pathogens, based on local surveillance and susceptibility data, and presence of risk factors for involvement of a resistant microorganism. Subsequent modification (de‐escalation) of the initial regimen becomes possible later, when culture results are available and clinical status can be better assessed, 2 to 4 days after initiation of empiric therapy. When possible, de‐escalation and other steps to modify antimicrobial exposure are important for minimizing risk of antimicrobial resistance development. This article examines the general process for selection of initial empiric antibiotic therapy for patients with HAIs, illustrated through 3 case studies dealing with healthcare‐associated pneumonia, complicated intra‐abdominal infection, and catheter‐associated bacteremia, respectively. Journal of Hospital Medicine 2012;7:S2–S12. © 2012 Society of Hospital Medicine

New insight on antimicrobial therapy adjustment strategies for gram-negative bacterial infection

“…As to therapy adjustment, a few studies have already found that if initial empirical therapy was not appropriate or adequate, subsequent adjustment based on culture results or MST could not reverse the worsened outcomes especially mortality, [15–17] and delayed therapy was also associated with higher mortality, longer hospitalization, and increased health care costs. [25,26] The results from these studies have been important basis of our current antimicrobial therapy strategy, in which prompt initiation of appropriate therapy and subsequent targeted therapy were suggested, but sometimes culture results were not available because of several negative results before a positive one, long culture time, or delayed report (in our study, the mean time from diagnosis to positive culture results was 6.66 [±8.40] days). Under this circumstance combined with seemingly not effective initial therapy, clinicians had to decide whether to change therapy or wait until positive culture results.…”

The challenge of post-operative peritonitis after gastrointestinal surgery

“…Given the results of this study, the inclusion of an anticandidal drug in empirical regimens for PP seems to be appropriate [63]. Subsequent modification (de-escalation) of the initial regimen becomes possible later, when culture results are available and clinical status can be better assessed, 24-72 h after initiation of empiric therapy [65]. All patients with PP require culture and drug susceptibility testing to guide targeted antibiotic therapy.…”

Airway Pseudomonas aeruginosa density in mechanically ventilated patients: clinical impact and relation to therapeutic efficacy of antibiotics

“…[19][20][21]. Antibiotic therapy was defined as appropriate when PA showed in vitro susceptibility to empiric antibiotics (administered within 24 h of sampling for culture) for patients with VAP or targeted antibiotics (started or changed based on culture results) for patients with VAT [1,22].…”