Numerous organizations have published guidelines on the management of community-acquired pneumonia. The most important English language guidelines are by the American Thoracic Society (ATS),⁷the British Thoracic Society,⁸the Canadian Infectious Disease Society,⁹ and the Infectious Diseases Society of America (IDSA).¹ These guidelines often conflict in key points.

Because emergency medicine physicians were not asked to contribute to these “consensus” guidelines, it is not surprising that these recommendations fall short regarding the emergency management of pneumonia. None of these guidelines are ideal for emergency medicine practice; the ATS guidelines are best in regards to diagnostic testing (with decreased emphasis on microbiologic studies such as cultures and Gram’s stains), while the IDSA guidelines on antibiotic selection are more current regarding antibiotic resistance patterns.

The IDSA emphasizes the microbiology aspects of the evaluation. While they attempt an evidence-based approach, they provide no scientifically valid literature to defend their position. Indeed, the expert panel states, “The Panel agrees that no studies have clearly demonstrated the cost-effectiveness or other advantages of attempts to identify etiologic pathogens...” but goes on to give several theoretical arguments to support their position.¹It is not  nexpected for the IDSA to suggest that cultures or Gram’s stains are necessary in the management of an infectious disease.