Each recommendation includes a ranking for the strength and the quality of evidence supporting it. Definitions of the levels of evidence (I-III) and grades of recommendation (A-E) are repeated at the end of the Major Recommendations field.
Recommendations for management of community-acquired pneumonia (CAP) in immunocompetent adults: summary of prior Infectious Diseases Society of America (IDSA) recommendations of 2000 and updated and new recommendations for 2003 (in bold).
Site of Treatment Decision
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 Outcome Research Team) Severity Index with recommendation for home care for risk classes I, II, and III; and (3) clinical judgment (A-II).
Hospitalized patients treated with intravenous antibiotics may be changed to oral antibiotics when the patient is clinically improving, is able to ingest drugs, is hemodynamically stable, and has a functioning gastrointestinal tract (A-I).
Discharge criteria: during the 24 h prior to discharge to home, the patient should have no more than 1 of the following characteristics (unless this represents the baseline status): temperature, >37.8 degrees 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).
Laboratory Tests
Chest radiography: All patients with suspected pneumonia should have a chest radiograph (A-II).
General assessment: Patients hospitalized for pneumonia should have a complete blood count; serum blood urea nitrogen, glucose, electrolytes, and liver function testing; and assessment of oxygen saturation (B-II). Persons aged 15–54 years should undergo human immunodeficiency virus (HIV) testing with informed consent (B-II).
Tests for an etiologic agent in ambulatory patients: No tests for an etiologic agent are considered standard for patients who are not hospitalized for pneumonia, but an air-dried slide of a pretreatment deep-cough sputum sample may subsequently prove useful (C-III).
Tests for etiologic agent in hospitalized patients: Patients hospitalized for pneumonia should have 2 pretreatment blood cultures (A-II) (this represents a change in rating) and expectorated sputum Gram stain and culture (B-II). The expectorated sputum specimen should be a deep-cough specimen obtained before antibiotic treatment that is rapidly transported and processed within a few hours of collection (B-II). Cytologic criteria should be used as a contingency for sputum culture, except with culture for Mycobacteria and Legionella species (A-I). Transtracheal aspiration, transthoracic aspiration, and bronchoscopy should be reserved for selected patients and done by physicians with appropriate expertise (B-III). Testing of induced sputum has established merit only for detection of Mycobacterium tuberculosis and Pneumocystis carinii (A-I).
Recommended Agent-specific Tests
Legionella: Testing for Legionella species is appropriate for any patient hospitalized with enigmatic pneumonia (C-II). This test is recommended for patients with enigmatic pneumonia sufficiently severe to require care in the intensive care unit, in the presence of an epidemic, or failure to respond to a beta-lactam (A-III).
Chlamydophila pneumoniae: Acceptable diagnostic methods for C. pneumoniae pulmonary infections are the demonstration of a 4-fold increase in immunoglobulin G (IgG) titer or single IgM titer of >1:16 using a microimmunofluorescence serologic test or isolation in tissue culture or a polymerase chain reaction (PCR) assay of respiratory secretions using reagents that satisfy optimal criteria for validation (B-III).
Streptococcus pneumoniae: Standard methods are blood culture and sputum for Gram stain and culture (B-II). The pneumococcal urinary antigen assay is an acceptable test to augment the standard diagnostic methods of blood culture and sputum Gram stain and culture, with the potential advantage of rapid results similar to those for sputum Gram stain (B-II).
Influenza virus: A rapid antigen detection assay for influenza virus is recommended for rapid detection of this pathogen for epidemiologic purposes and/or treatment (CII). Tests that distinguish between influenza A and B are generally preferred (C-III).
Respiratory syncytial virus: Antigen detection tests are readily available but are insensitive for detecting infections in adults and are not generally recommended for adults (C-III).
Means of diagnosis for category A agents of bioterrorism: for inhalation anthrax, blood culture (A-I) and chest computed tomography (CT) scan (A-I); for pneumonic plague, blood culture and Gram stain and culture of sputum samples (A-I); and for tularemic pneumonia, culture of blood and sputum or pharynx in a biocontainment level 3 laboratory (A-I).
Severe Acute Respiratory Syndrome (SARS): Diagnostic criteria include clinical and epidemiologic features and may include diagnostic studies for the coronavirus (A-I). Recommended virologic studies for laboratory confirmation are (1) culture for SARS coronavirus, (2) detection of antibody during the acute phase of illness or any time after onset, or (3) detection of SARS coronavirus ribonucleic acid (RNA) confirmed by second polymerase chain reaction (PCR) assay by using a second aliquot of the specimen or a different set of primers. (The panel considers it premature to rate the use of virologic tests.)
Interpretation of Cultures
Etiologic diagnosis is established with recovery of a probable etiologic agent from an uncontaminated specimen (blood, pleural fluid, transtracheal aspirate, or transthoracic aspirate) or with recovery from respiratory secretions of a likely pathogen that does not colonize the upper airways (e.g., M. tuberculosis, Legionella species, influenza virus, respiratory syncytial virus, parainfluenza virus, adenovirus, SARS coronavirus, P. carinii, Histoplasma capsulatum, Coccidioides immitis, and Blastomyces dermatidis) (A-I).
Etiologic diagnosis is probable with a compatible clinical syndrome combined with detection by stain or culture of a likely pulmonary pathogen in respiratory secretions (expectorated sputum or bronchoscopic secretions); with culture, there should be significant growth with quantitative culture or moderate or heavy growth with semiquantitative culture (B-II).
Serologic tests are usually not helpful in the initial evaluation (C-III) but may be useful for epidemiologic surveillance.
Deoxyribonucleic acid (DNA) probes and nucleic acid amplification assays are under development especially for C. pneumoniae, M. pneumoniae, and Legionella species. These tests are not currently recommended because reagents have not had U.S. Food and Drug Administration (FDA) clearance; availability is largely restricted to research laboratories, and studies show results that are variable (C-III).
Antimicrobial Treatment
Pathogen-specific Therapy
S. pneumoniae: Susceptibility of S. pneumoniae isolates to cefotaxime and ceftriaxone in nonmeningeal infections should be defined as a minimum inhibitory concentration (MIC) of <1 micrograms/mL, intermediate should be defined as an MIC of 2 micrograms/mL, and resistant should be defined as an MIC of >4 micrograms/mL (A-III). Cefotaxime or ceftriaxone are the preferred parenteral agents for treatment of pneumococcal pneumonia without meningitis for strains with reduced susceptibility to penicillin but with MICs of cefotaxime or ceftriaxone of <2 micrograms/mL (B-III). Amoxicillin is the preferred antibiotic for oral treatment of pneumococcal pneumonia involving susceptible strains (B-II).
Initial empiric therapy prior to availability of culture data for a patient ill enough to require admission to a hospital ward can be with a beta-lactam plus macrolide combination or a respiratory fluoroquinolone alone (A-I). If sufficiently ill to need intensive care unit (ICU) management and if Pseudomonas infection is not a concern, a combination of a beta-lactam plus either a macrolide or a respiratory fluoroquinolone should be used (B-III). Once culture data are available and it is known that the patient has pneumococcal pneumonia with bacteremia without evidence to support infection with a copathogen, treatment will depend upon in vitro susceptibility results. If the isolate is penicillin susceptible, a beta-lactam (penicillin G or amoxicillin) alone may be used (B-II). If the isolate is penicillin resistant, cefotaxime, ceftriaxone, or a respiratory fluoroquinolone or other agent indicated by in vitro testing may be used (A-III).
Legionella: Treatment for Legionnaires' disease is appropriate when there is epidemiologic evidence of this disease, despite negative diagnostic test results (B-III). The preferred treatment for Legionnaires' disease for hospitalized patients is azithromycin or a fluoroquinolone (moxifloxacin, gatifloxacin, and levofloxacin; gemifloxacin is only available as an oral formulation) (B-II). For patients who do not require hospitalization, acceptable antibiotics include erythromycin, doxycycline, azithromycin, clarithromycin, or a fluoroquinolone (A-II). Treatment should be initiated as rapidly as is feasible (A-II).
Influenza: Early treatment (within 48 h after onset of symptoms) is effective in the treatment of influenza A using amantadine, rimantadine, oseltamivir, or zanamivir and is effective in the treatment of influenza B using oseltamivir and zanamivir (B-I). Use of these drugs is not recommended for uncomplicated influenza with a duration of symptoms of >48 h (D-I), but these drugs may be used to reduce viral shedding in hospitalized patients or for influenza pneumonia (C-III).
Herpes viruses: Pneumonia caused by varicella zoster virus or herpes simplex virus should be treated with parenteral acyclovir (A-II).
Other viruses: There is no antiviral agent with established efficacy for the treatment of adults with pulmonary infections involving parainfluenza virus, respiratory syncytial virus, adenovirus, metapneumovirus, the SARS agent, or Hantavirus (D-I).
Empiric Therapy
See Table 1 below for initial therapy recommendations.
Empiric treatment of suspected bacterial superinfection of influenza should provide activity against S. pneumoniae, Staphylococcus aureus, and Haemophilus influenzae with antibiotics such as amoxicillin-clavulanate, cefpodoxime, cefprozil, cefuroxime, or a respiratory fluoroquinolone (B-III).
Fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin) are recommended for initial empiric therapy of selected outpatients with CAP (A-I). Other options (macrolides and doxycycline) are generally preferred for uncomplicated infections in outpatients (A-I). Fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin) may be used as monotherapy for patients with CAP who are admitted to a hospital ward (A-I). With the exception of gemifloxacin (no intravenous formulation), they may be used as part of a combination for patients with CAP admitted to an ICU (C-III).
A macrolide is recommended as monotherapy for selected outpatients, such as those who were previously well and not recently treated with antibiotics (A-I). A macrolide plus a beta-lactam is recommended for initial empiric treatment of outpatients in whom resistance is an issue and for hospitalized patients (A-I).
Telithromycin may have a role as an alternative to macrolides for treatment of patients with CAP. At this time, however, it is not yet approved by the FDA.
Special Populations and Circumstances
SARS: Health care workers must be vigilant in recognizing SARS because of important epidemiologic implications, which include the potential for rapid spread to close contacts, including health care workers and household contacts (A-III). The major therapeutic intervention is supportive care (B-III). Preventive efforts include proper precautions in patients with suspected or established SARS. These include standard precautions (hand hygiene), contact precautions (use of gowns, goggles, and gloves), and airborne precautions (use of negative-pressure rooms and fit-tested N95 respirators) (A-I).
Elderly patients: Antimicrobial selection for elderly patients with CAP is the same as for all adults with CAP (B-III).
Bioterrorism: Physicians should know the clues to bioterrorism and the appropriate mechanisms to alert public health officials in cases of suspected bioterrorism (A-III). Recommended diagnostic tests and management guidelines are those of the Johns Hopkins Center for Biodefense Strategies and of the Centers for Disease Control and Prevention (CDC), as modified for the specific outbreak (A-I).
Performance Indicators
Blood cultures prior to antibiotic therapy in patients hospitalized for pneumonia (B-III).
Antibiotic therapy should be initiated within 4 h after registration for hospitalized patients with CAP (B-III).
Smoking cessation should be a goal for persons hospitalized with CAP who smoke (B-II).
Legionella tests (culture and/or urinary antigen assay) for 50% of patients who are hospitalized in the ICU for severe enigmatic pneumonia (A-III).
Assessment of oxygenation by arterial blood-gas testing or pulse oximetry within 8 h after admission (A-III).
Demonstration of an infiltrate by chest radiograph or other imaging techniques in all patients who have an International Classification of Diseases (ICD)-9 code diagnosis of CAP and who do not have acquired immune deficiency syndrome (AIDS) or neutropenia (A-I).
Prevention of CAP
All persons >50 years, others at risk for influenza complications, and household contacts of high-risk persons should receive inactivated influenza vaccine, as recommended by the Advisory Committee on Immunization Practices (ACIP) (A-I). The injected inactivated vaccine is the preferred formulation for most persons at risk of complications associated with influenza, for household contacts of high-risk persons, and for health care workers (A-I). The intranasally administered live, attenuated vaccine (FluMist; Aventis) is an alternative vaccine formulation for some persons aged 5 to 49 years without chronic underlying diseases, including immunodeficiency, asthma, and chronic medical conditions (C-I). Influenza vaccine should be offered to persons at hospital discharge or during outpatient treatment during the fall and winter (C-III). Health care workers in inpatient and outpatient settings and long-term care facilities should receive annual influenza immunization (A-I).
Pneumococcal polysaccharide vaccine (Pneumovax; MedImmune [marketed by Wyeth in the United States]) is recommended for use, according to current ACIP guidelines, including use for persons aged >65 years and for those with selected high-risk concurrent diseases (B-II). Vaccination may be done either at hospital discharge or during outpatient treatment (C-III).
Table 1. Initial empiric therapy for suspected bacterial community-acquired pneumonia (CAP) in immunocompetent adults
| Patient variable
|
Preferred treatment options
|
| Outpatient |
|
Previously healthy |
|
No recent antibiotic therapy |
A macrolidea or doxycycline |
Recent antibiotic therapyb |
A respiratory fluoroquinolonec alone, an advanced macrolided plus high-dose amoxicillin,e or an advanced macrolide plus high-dose amoxicillin-clavulanatef |
Comorbidities (chronic obstructive pulmonary disease (COPD), diabetes, renal or congestive heart failure, or malignancy) |
|
No recent antibiotic therapy |
An advanced macrolided or a respiratory fluoroquinolone |
Recent antibiotic therapyb |
A respiratory fluoroquinolonec alone or an advanced macrolide plus a beta-lactamg |
Suspected aspiration with infection |
Amoxicillin-clavulanate or clindamycin |
Influenza with bacterial superinfection |
A beta-lactamg or a respiratory fluoroquinolone |
| Inpatient |
|
Medical ward
| |
No recent antibiotic therapyb |
A respiratory fluoroquinolone alone or an advanced macrolide plus a beta-lactamh |
Recent antibiotic therapyb |
An advanced macrolide plus a beta-lactam or a respiratory fluoroquinolone alone (regimen selected will depend on nature of recent antibiotic therapy) |
ICU |
|
Pseudomonas infection is not an issue |
A beta-lactamh plus either an advanced macrolide or a respiratory fluoroquinolone |
Pseudomonas infection is not an issue but patient has a beta-lactam allergy |
A respiratory fluoroquinolone, with or without clindamycin |
Pseudomonas infection is an issuei |
Either (1) an antipseudomonal agentj plus ciprofloxacin, or (2) an antipseudomonal agent plus an aminoglycosidek plus a respiratory fluoroquinolone or a macrolide |
Pseudomonas infection is an issue but the patient has a beta-lactam allergy |
Either (1) aztreonam plus levofloxacin,l or (2) aztreonam plus moxifloxacin or gatifloxacin, with or without an aminoglycoside |
Nursing home |
|
Receiving treatment in nursing home |
A respiratory fluoroquinolone alone or amoxicillin-clavulanate plus an advanced macrolide |
Hospitalized |
Same as for medical ward and ICU |
a Erythromycin, azithromycin, or clarithromycin.
b That is, the patient was given a course of antibiotic(s) for treatment of any infection within the past 3 months, excluding the current episode of infection. Such treatment is a risk factor for drug-resistant Streptococcus pneumoniae and possibly for infection with gram-negative bacilli. Depending on the class of antibiotics recently given, one or other of the suggested options may be selected. Recent use of a fluoroquinolone should dictate selection of a nonfluoroquinolone regimen, and vice versa.
c Moxifloxacin, gatifloxacin, levofloxacin, or gemifloxacin (oral gemifloxacin only, which was approved by the US Food and Drug Administration on 4 April 2003 and which is the only fluoroquinolone approved for multidrug-resistant S. pneumoniae; not yet marketed).
d Azithromycin or clarithromycin.
e Dosage, 1 g po t.i.d.
f Dosage, 2 g po b.i.d.
g High-dose amoxicillin, high-dose amoxicillin-clavulanate, cefpodoxime, cefprozil, or cefuroxime.
h Cefotaxime, ceftriaxone, ampicillin-sulbactam, or ertapenem; ertapenem was recently approved for such use (in once-daily parenteral treatment), but there is little experience thus far.
i The antipseudomonal agents chosen reflect this concern. Risk factors for Pseudomonas infection include severe structural lung disease (e.g., bronchiectasis), and recent antibiotic therapy or stay in hospital (especially in the ICU). For patients with CAP in the ICU, coverage for S. pneumoniae and Legionella species must always be assured. Piperacillin-tazobactam, imipenem, meropenem, and cefepime are excellent beta-lactams and are adequate for most S. pneumoniae and Haemophilus influenzae infections. They may be preferred when there is concern for relatively unusual CAP pathogens, such as Pseudomonas aeruginosa, Klebsiella species, and other gram-negative bacteria.
j Piperacillin, piperacillin-tazobactam, imipenem, meropenem, or cefepime.
k
Data suggest that elderly patients receiving aminoglycosides have worse outcomes.
l Dosage for hospitalized patients, 750 mg q.d.
Definitions:
Quality of Evidence
- Evidence from at least one properly randomized, controlled trial
- Evidence from at least one well-designed clinical trial without randomization, from cohort or case-controlled analytic studies (preferably from more than one center), or from multiple time-series studies or dramatic results from uncontrolled experiments
- Evidence from opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees
Strength of Recommendation
- Good evidence to support a recommendation for use
- Moderate evidence to support a recommendation for use
- Poor evidence to support a recommendation
- Moderate evidence to support a recommendation against use
- Good evidence to support a recommendation against use
