Based on emerging new evidence, a multidisciplinary panel of experts put together by the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) released updated recommendations for the management of adults with community-acquired pneumonia (CAP). This report was published in Annals of the American Thoracic Society.
Investigators performed a systematic review of literature focused on postdiagnostic treatment strategies for the management of CAP. The recommended guidelines have unique implications for clinicians, patients, and policymakers; clinicians should further consider the patient’s individual circumstances in managing CAP.
Recommendations for Respiratory and Blood Cultures
The panel recommends obtaining pretreatment sputum Gram stain and culture of respiratory secretions in adults with severe CAP who are managed in a hospital setting (strong recommendation, very low quality of evidence); however, they advise against the routine collection of blood cultures in these patients. Obtaining blood cultures in an outpatient setting, whether on a routine basis or prior to treatment, is not recommended (strong recommendation, very low quality of evidence). For improved identification of causative pathogens in CAP, the panel indicates the need for new diagnostic tests that better distinguish between infection and colonization.
Recommendations for Streptococcus pneumoniae and Legionella Urinary Antigens
The panel recommends against routine testing of urine for pneumococcal antigen or Legionella antigen in adults with CAP, except in severe cases of CAP or when patients report an association with Legionella outbreak or recent travel (all recommendations: conditional recommendation, low quality of evidence). In addition to testing urine in adults with severe CAP, lower respiratory tract secretions for Legionella culture should be collected using selective media or Legionella nucleic acid amplification (conditional recommendation, low quality of evidence).
Recommendations for Influenza Testing
A rapid influenza molecular assay (eg, the influenza nucleic acid amplification test) is strongly recommended over a rapid influenza diagnostic test, as molecular testing is more accurate and has additional implications related to infection control and therapeutic strategy (strong recommendation, moderate quality of evidence).
Recommendations for Procalcitonin
In adults with clinically suspected or radiographically confirmed CAP, the panel strongly recommends initiating empiric antibiotic therapy regardless of initial serum procalcitonin level (strong recommendation, moderate quality of evidence).
Recommendations for Determining Inpatient vs Outpatient Treatment Location
Clinicians should use a validated clinical prediction rule for prognosis and to determine the need for hospitalization in adults diagnosed with CAP (strong recommendation, moderate quality of evidence). Although the CURB-65 scale is simpler to use, the preferred prognostication tool for CAP is the Pneumonia Severity Index which has been associated with the reduction of low-risk hospitalizations.
Recommendations for Inpatient Level of Care
The panel recommends direct intensive care unit admission for patients with respiratory failure requiring mechanical ventilation or with hypotension requiring vasopressors (strong recommendation, low quality of evidence). To identify an immediate need for intensive care unit therapies among patients who do not require a ventilator or vasopressor support, the panel recommends using IDSA/ATS 2007 minor severity criteria along with clinical judgment (conditional recommendation, low quality of evidence).
Recommendations for Antibiotic Regimens
Outpatient Adults Without Comorbidities
The panel believes the single agent amoxicillin can be safely prescribed to outpatients with CAP; doxycycline is also recommended in this patient population as it boosts activity against the most common CAP organisms. Macrolide monotherapy may be prescribed in outpatients; however, the prescription should depend on local resistance patterns.
Outpatient Adults With Comorbidities
Patients with diabetes, alcoholism, malignancy, asplenia, or chronic heart, lung, or renal disease may be more vulnerable to antibiotic-resistant organisms and are therefore recommended to initiate combination antibiotic regimens. Respiratory fluoroquinolones may be justified in some cases despite potential adverse events.
Adults Hospitalized With Nonsevere CAP
The panel recommends combination therapy with beta-lactam and macrolide or monotherapy with a fluoroquinolone regimen. In cases of adults who have contraindications to macrolides and fluoroquinolones, combination therapy with beta-lactam and doxycycline may be considered; however, the panel recommends against the routine use of beta-lactam monotherapy as it has been associated with worse outcomes.
Adults Hospitalized With Severe CAP
Although the safety of fluoroquinolone monotherapy has not been established in the treatment of severe CAP, the panel strongly recommends combination therapies containing beta-lactam plus a macrolide, doxycycline, or respiratory fluoroquinolone (low quality of evidence).
Recommendations for Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa Risk Assessment
The panel recommends against the categorization of healthcare-associated pneumonia because it does not accurately predict risk for resistant organisms; extended antibiotic coverage in adults with CAP should only be considered for Methicillin-resistant Staphylococcus aureus (MRSA) or P aeruginosa (strong recommendation, moderate quality of evidence). Continuation of empiric treatment after the first few days is only justified if local culture data is available establishing the presence of these pathogens (strong recommendation, moderate quality of evidence).
Empiric treatment options for patients with MRSA include vancomycin or linezolid; options for patients with P aeruginosa include piperacillin-tazobactam, cefepime, ceftazidime, aztreonam, meropenem, or imipenem.
Recommendations for Anaerobic Coverage for Suspected Aspiration Pneumonia
Unless a pulmonary abscess or empyema is suspected, the panel conditionally recommends against the routine addition of anaerobic coverage for traditional aspiration pneumonia as anaerobic bacteria are typically uncommon (very low quality of evidence).
Recommendations for Corticosteroids and CAP
Routine use of corticosteroids is not recommended in adults with nonsevere (strong recommendation, high quality of evidence) or severe CAP (conditional recommendation, moderate quality of evidence) or with severe influenza pneumonia (conditional recommendation, low quality of evidence). However, the panel endorses corticosteroid use in patients with CAP and refractory septic shock and recommends following the Surviving Sepsis Campaign guidelines.
Recommendations for Influenza-Positive CAP and Antiviral Therapy
In both inpatient and outpatient settings, the panel recommends the use of anti-influenza therapies (eg, oseltamivir) to treat adults with CAP who test positive for influenza regardless of the illness duration prior to diagnosis (inpatient setting: strong recommendation, moderate quality of evidence; outpatient setting: conditional recommendation, low quality of evidence).
Recommendations for Influenza-Positive CAP and Antibacterial Therapy
In adults with CAP who test positive for influenza, the panel recommends an initial prescription of antibacterial treatment to reduce the risk for bacterial coinfections in both inpatient and outpatient settings (strong recommendation, low quality of evidence).
Recommendations for Antibiotic Treatment Duration
Antibiotic therapy should be continued until a patient achieves clinical stability — measured as a resolution of vital sign abnormalities (heart rate, respiratory rate, blood pressure, oxygen saturation, temperature), ability to eat, and normal mentation — and for no fewer than 5 days (strong recommendation, moderate quality of evidence) unless a patient has suspected MRSA or P aeruginosa in which case antibiotics should be prescribed for at least 7 days.
Recommendations for Chest Imaging After CAP
The panel recommends against routine chest imaging in follow-up care for adults with CAP whose symptoms have resolved within 5 to 7 days (conditional recommendation, low quality of evidence).
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see original reference for a full list of authors’ disclosures.
Jones BE, Herman DD, Dela Cruz CS, et al. Summary for clinicians: clinical practice guideline for the diagnosis and treatment of community-acquired pneumonia [published online November 26, 2019]. Ann Am Thorac Soc. doi:10.1513/AnnalsATS.201909-704CME