While treating infectious diseases in the ED, physicians need to apply a vast amount of knowledge — not only of appropriate antibiotics, but also of microbiology, diagnostic testing, and the pathophysiology of the patient’s underlying disease. In everyday practice, it is usually not possible to do a bedside literature search that would take all those factors into account. Most of us use our “memories” or a guidebook, or some combination, uncertain of the real quality of scientific proof that stands behind our decisions. In this article we will move onto firmer ground by distilling some of the existing evidence into concise practical guidelines.

There is an enormous amount of literature on antibiotics, but the quality varies widely. The best evidence found in preparation of this manuscript came from the Cochrane Database of Systematic Reviews, which offers information about the strength of the evidence supporting each conclusion and allows users to assess the validity of the meta-analysis. Another important source of information came from practice guidelines developed by specialty societies and expert panels, eg, the guidelines for treatment of community-acquired pneumonia published by the American College of Emergency Physicians.² A third source of information was the National Guideline Clearinghouse at http://www.guidelines.gov, which was created by the Agency for Healthcare Research and Quality (AHRQ), US Department of Health and Human Services, in partnership with the American Medical Association and the American Association of Health Plans (now America’s recommendations the authors thought important for practicing emergency physicians to be aware of. Finally, there is an enormous amount of information from other sources, ranging from case reports to well-designed, randomized double-blind studies. Great care was taken interpreting the strength of evidence provided by these sources and formulating recommendations based on the best available evidence. Health Insurance Plans [AHIP]).³ Table 1 provides a list of recommendations the authors thought important for practicing emergency physicians to be aware of. Finally, there is an enormous amount of information from other sources, ranging from case reports to well-designed, randomized double-blind studies. Great care was taken interpreting the strength of evidence provided by these sources and formulating recommendations based on the best available evidence.