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

Abstract

Guidelines for the management of community-acquired pneumonia were issued on behalf of the Infectious Diseases Society of America in April 1998. The present version represents a revision of these guidelines issued in February 2000; updates at 6- to 12-month intervals are anticipated. A summary of these guidelines follows. Grading system. Recommendations are categorized by the letters A–D, according to the strength of the recommendation: A, good evidence to support the recommendation; B, moderate evidence to support the recommendation; C, poor evidence to support the recommendation; and D, evidence against the recommendation. The recommendations are also graded by the quality of the evidence to support the recommendation, on the basis of categories I–III; I, at least 1 randomized controlled trial supports the recommendation; II, evidence from at least 1 well-designed clinical trial without randomization supports the recommendation; and III, “expert opinion.” Chest radiography. Chest radiography is considered critical for establishing the diagnosis of pneumonia and for distinguishing this condition from acute bronchitis (AB), which is a common cause of antibiotic abuse. Site of care. Recommendations regarding the decision for hospitalization are based on the methodology used in the clinical prediction rule for short-term mortality, from the publications of the Pneumonia Patient Outcome Research Team (Pneumonia PORT). Patients are stratified into 5 severity classes by means of a 2-step process. Class I indicates an age <50 years, with none of 5 comorbid conditions (neoplastic disease, liver disease, congestive heart failure, cerebrovascular disease, or renal disease), normal or only mildly deranged vital signs, and normal mental status. In step 2, patients not assigned to risk class I are stratified in classes II–V on the basis of points assigned for 3 demographic variables (age, sex, and nursing home residency), 5 comorbid conditions (summarized above), 5 physical examination findings, and 7 laboratory and/or radiographic findings. Patients in risk classes I and II do not usually require hospitalization, those in risk class III may require brief hospitalization, and those in risk classes IV and V usually require hospitalization. It should be noted that social factors, such as outpatient support mechanisms and probability of adherence, are not included in this assessment. Laboratory tests. All patients thought to have pneumonia should undergo chest radiography. The following laboratory values should be determined for patients who are hospitalized: complete blood cell count and differential, serum creatinine, blood urea nitrogen, glucose, electrolytes, and liver function tests. HIV serology with informed consent should be considered, especially for persons aged 15–54 years. Oxygen saturation should be assessed. There should be 2 pretreatment blood cultures, as well as Gram staining and culture of expectorated sputum. Selected patients should have microbiological studies for tuberculosis and legionella infection. The preferred tests for detection of Legionella species are the urinary antigen assay for Legionella pneumophila serogroup 1 and culture with selective media. The rationale for performing microbiological studies to establish an etiologic diagnosis is based on attempts to improve care of the individual patient with pathogen-specific treatment; to improve care of other patients and to advance knowledge by detecting epidemiologically important organisms (Legionella, penicillin-resistant Streptococcus pneumoniae, and methicillin-resistant Staphylococcus aureus); to implement contact-tracing and antimicrobial prophylaxis in appropriate settings (such as cases of Neisseria meningitidis infection, Haemophilus influenzae type B infection, and tuberculosis); to prevent antibiotic abuse; and to reduce antibiotic expense. Antimicrobial therapy. Recommendations are provided for pathogen-specific treatment in cases in which an etiologic diagnosis is established or strongly suspected. If this information is not available initially but is subsequently reported, changing to the antimicrobial agent that is most cost-effective, least toxic, and most narrow in spectrum is encouraged. Recommendations for treating patients who require empirical antibiotic selection are based on severity of illness, pathogen probabilities, resistance patterns of S. pneumoniae (the most commonly implicated etiologic agent), and comorbid conditions. The recommendation for outpatients is administration of a macrolide, doxycycline, or fluoroquinolone with enhanced activity against S. pneumoniae. For patients who are hospitalized, the recommendation is administration of a fluoroquinolone alone or an extended-spectrum cephalosporin (cefotaxime or ceftriaxone) a Patients in the care should or in with a fluoroquinolone or other those are not may be to the patient is is and is to patients a clinical on chest usually the clinical and chest radiography