Guidelines for the management of adults with community-acquired pneumonia diagnosis, assessment of severity, antimicrobial therapy, and prevention

The initial approach to managing patients with community-acquired pneumonia involves a determination of the presence of relevant factors that influence the likely etiologic pathogens. These factors include place of therapy (inpatient versus outpatient), the presence of cardiopulmonary disease, the presence of risk factors for drug-resistant pneumococci, the presence of risk factors for enteric gram-negative bacteria (including P. aeruginosa), and the severity of illness at presentation (mild, moderate, or severe). Once these assessments have been made, initial antimicrobial therapy can be selected according to the recommendations in Tables 2-5, and the choices will cover the most common pathogens likely for a given clinical setting. It is important to evaluate the response to initial therapy so that patients who are not adequately improving can be identified and properly evaluated. The approach advocated in Tables 2-5 is different from several common clinical practices that have no firm basis in published studies. The practices include the use of sputum Gram's stain to define the likely etiologic pathogen and to guide initial therapy of community-acquired pneumonia; the use of extensive diagnostic testing in the initial evaluation of etiology; and the use of clinical syndromes to predict microbial etiology. In several important areas of management, data are limited, and recommendations are not based on a firm scientific foundation. Future studies should focus on some of these pressing, but unanswered, questions: (1) How long should therapy be continued? (2) Should duration of therapy be related to severity of initial illness? (3) What role does antibiotic resistance play in the outcome of patients with CAP and how should initial therapy be modified to account for possible resistance? (4) Will newer diagnostic methods improve our ability to define the etiologic pathogens of community-acquired pneumonia, and will this information lead to improved outcomes? (5) What are the best criteria for defining the need for hospitalization? (6) How will antibiotic choices and guidelines for empiric therapy impact future patterns of antibiotic resistance? (7) Is atypical pathogen coinfection common and if so, is it prevalent all the time, or are there temporal and geographic variables to consider? Often the distinction between pneumonia and bronchitis is uncertain, since even the chest radiograph may not be sensitive to early forms of pneumonia. This document is focused on the management of CAP, but the role of antibiotic therapy in patients with AECB needs further study, with a particular focus on whether specific types of antibiotic therapy should be targeted to specific patient populations. However, for CAP, the committee believes that guidelines can be useful for initial patient management, and the guidelines suggest therapies for illnesses that are based on the premise of using the "right drug for the right patient," recognizing that patient profiles dictate different therapies for different clinical settings.