Update of Practice Guidelines for the Management of Community-Acquired Pneumonia in Immunocompetent Adults

Abstract

The Infectious Diseases Society of America (IDSA) produced guidelines for community-acquired pneumonia (CAP) in immunocompetent adults in 1998 and again in 2000 [1, 2]. Because of evolving resistance to antimicrobials and other advances, it was felt that an update should be provided every few years so that important developments could be highlighted and pressing questions answered. We addressed those issues that the committee believed were important to the practicing physician, including suggestions for initial empiric therapy for CAP. In some cases, only a few paragraphs were needed, whereas, in others, a somewhat more in-depth discussion was provided. Because many physicians focus on the tables rather than on the text of guidelines, it was decided that all of the information dealing with the initial empiric treatment regimens should be in tabular format with footnotes (tables 1–3). The topics selected for updating have been organized according to the headings used in the August 2000 CAP guidelines published in Clinical Infectious Diseases [2]. The major headings were “Epidemiology,” “Diagnostic Evaluation,” “Special Considerations,” “Management,” “Prevention,” and “Performance Indicators,” and each section had a number of subentries. Our current topics are either updates of specific subheadings or are new contributions, and the committee's recommendations are given at the beginning of each section. A summary of prior IDSA recommendations presented in 2000 and the updated and new recommendations can be found in table 4. Ratings of the strength of the supporting evidence and the quality of the data are given in parentheses after each recommendation, and the grading system used to categorize them is in table 5. The next guidelines for the treatment of CAP will be a joint effort by the IDSA and the American Thoracic Society (ATS). A working group representing both societies has been formed and is already at work on the next CAP treatment guidelines. Recommendation 1. The initial site of treatment should be based on a 3-step process: (1) assessment of preexisting conditions that compromise safety of home care; (2) calculation of the pneumonia PORT (Pneumonia Outcomes Research Team) Severity Index (PSI) with recommendation for home care for risk classes I, II, and III; and (3) clinical judgment (A-II). Recommendation 2. For discharge criteria, during the 24 h prior to discharge to the home, the patient should have no more than 1 of the following characteristics (unless this represents the baseline status): temperature, >37.8°C; pulse, >100 beats/min; respiratory rate, >24 breaths/min; systolic blood pressure, <90 mm Hg; blood oxygen saturation, <90%; and inability to maintain oral intake (B-I). Comment. Selection of the initial site of treatment, whether home or hospital, continues to be one of the most important clinical decisions made in the treatment of patients with CAP, often determining the selection and route of administration of antibiotic agents, intensity of medical observation, and use of medical resources. This decision is often made in the emergency department, the portal of entry for 75% of the 1 million annual pneumonia admissions in the United States. Two recent articles suggest that the initial site of treatment decision be selected using a systematic 3-step process [3, 4]. Step 1 involves assessment of any preexisting conditions that compromise the safety of home care, including severe hemodynamic instability, active coexisting conditions that require hospitalization, acute hypoxemia or chronic oxygen dependency, and inability to take oral medications. The second step involves calculation of the pneumonia PSI, with a recommendation for home care for patients in risk classes I, II, or III. A description of how the PSI is derived is shown in Appendix A. The third step involves clinical judgment regarding the overall health of the patient and the suitability for home care. Mitigating factors for step 3 include frail physical condition, severe social or psychiatric problems compromising home care (including a history of substance abuse), and an unstable living situation or homelessness. Clinical judgment should supercede decisions made on the basis of PSI alone. At the present time, 3 North American medical practice guidelines advocate use of the PSI as an objective measure of risk stratification to help determine the initial site of treatment for CAP [2, 5, 6]. Preliminary results from the Emergency Department Triage of Community-Acquired Pneumonia Study indicate that implementation of the PSI significantly increases the proportion of low-risk patients with pneumonia managed in the emergency department who are treated as outpatients without compromising outcomes, as measured by short-term mortality or subsequent hospitalization [7]. In this randomized, controlled study that involved 32 hospital emergency departments and >3200 patients with CAP, implementation of the PSI with high- and moderate-in