Community-Acquired Pneumonia (CAP) Clinical Practice Guidelines (2019)

The Infectious Diseases Society of America (IDSA) and American Thoracic Society (ATS) issued clinical practice guidelines for community-acquired pneumonia (CAP) in adults in October 2019.^[1]

Diagnosis

Gram stain and sputum culture

Routine sputum culture and Gram stain are not recommended in adult outpatients with community-acquired pneumonia (CAP).

In hospitalized patients, pretreatment Gram stain and culture of respiratory secretions are recommended in adults with CAP that is considered severe (particularly in intubated patients) or who meet one of the following conditions:

Is currently receiving empiric treatment for methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa
Previously had MRSA or P aeruginosa infection, especially of the respiratory tract
Was hospitalized within the preceding 90 days and received parenteral antibiotics for any reason

Blood culture

Blood cultures are not recommended in adult outpatients with CAP.

Routine blood cultures are not recommended in hospitalized adults with CAP.

Pretreatment blood cultures are recommended in hospitalized adults with CAP that is classified as severe or who meet one of the following conditions:

Is currently receiving empiric treatment for MRSA or P aeruginosa
Previously had MRSA or P aeruginosa infection, especially of the respiratory tract
Was hospitalized within the preceding 90 days and received parenteral antibiotics for any reason

Legionella and pneumococcal urinary antigen testing

Routine urine testing for pneumococcal antigen is not recommended in adults with CAP unless the CAP is severe.

Routine urine testing for Legionella antigen is not recommended in adults with CAP unless the CAP is severe or as indicated based on predisposing epidemiological factors (eg, Legionella outbreak or recent travel).

Legionella testing should consist of urinary antigen assessment and collection of lower respiratory tract secretions for culture on selective media or nucleic acid amplification.

Influenza testing

If influenza is circulating in the community, influenza testing in adults with CAP is recommended with a rapid influenza molecular assay, which is preferred over a rapid influenza diagnostic test.

Procalcitonin testing

Empiric antibiotic therapy is recommended in adults with clinically suspected and radiographically confirmed CAP, regardless of the patient’s initial serum procalcitonin level.

Treatment

Decision for hospitalization

The decision for hospitalization in adults with CAP should be based on clinical judgement plus a validated clinical prediction rule for prognosis. The Pneumonia Severity Index (PSI) is preferred over the CURB-65.

ICU admission

Direct ICU admission is recommended for patients with CAP who have hypotension requiring vasopressors or respiratory failure requiring mechanical ventilation.

In patients who do not require vasopressors or a mechanical ventilator, the IDSA/ATS 2007 minor severity criteria, along with clinical judgment, are suggested for deciding whether to escalate treatment intensity.

Outpatient antibiotic regimens

The following antibiotics are recommended in adult patients with CAP who are otherwise healthy:

Amoxicillin 1 g three times daily OR
Doxycycline 100 mg twice daily OR
In areas with pneumococcal resistance to macrolides <25%: a macrolide (azithromycin 500 mg on day one and then 250 mg daily or clarithromycin 500 mg twice daily or clarithromycin extended-release 1,000 mg daily)

In outpatient adults with CAP who have comorbidities, the following antibiotic regimens are recommended:

Combination therapy:
- Amoxicillin/clavulanate 500 mg/125 mg 3 times daily OR amoxicillin/clavulanate 875 mg/125 mg twice daily OR 2,000 mg/125 mg twice daily OR a cephalosporin (cefpodoxime 200 mg twice daily or cefuroxime 500 mg twice daily) PLUS
- A macrolide (azithromycin 500 mg on day one then 250 mg daily, clarithromycin [500 mg twice daily or extended release 1,000 mg once daily]) or doxycycline 100 mg twice daily OR
Monotherapy: Respiratory fluoroquinolone (levofloxacin 750 mg daily, moxifloxacin 400 mg daily, or gemifloxacin 320 mg daily)

Inpatient antibiotic regimens

The following empiric treatment regimens are recommended in inpatient adults with nonsevere CAP who do not have risk factors for MRSA or P aeruginosa:

Combination therapy with a beta-lactam (ampicillin plus sulbactam 1.5-3 g every 6 hours, cefotaxime 1-2 g every 8 hours, ceftriaxone 1-2 g daily, or ceftaroline 600 mg every 12 hours) and a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily) OR
Monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg daily, moxifloxacin 400 mg daily)

The following regimens are recommended among inpatient adults with severe CAP without risk factors for MRSA or P aeruginosa:

A beta-lactam plus a macrolide OR
A beta-lactam plus a respiratory fluoroquinolone

Anaerobic coverage for suspected aspiration pneumonia

Routine addition of anaerobic coverage for suspected aspiration pneumonia is not recommended except when lung abscess or empyema is suspected.

Extended-spectrum antibiotic therapy for MRSA or P aeruginosa

For guiding selection of extended-spectrum antibiotic coverage in adults with CAP, the prior categorization of healthcare-associated pneumonia (HCAP) should be abandoned.

Empiric coverage for MRSA or P aeruginosa is recommended in adults with CAP only in the presence of locally validated risk factors. Empiric treatment options for MRSA include vancomycin (15 mg/kg every 12 hours) or linezolid (600 mg every 12 hours). Empiric treatment options for P aeruginosa include piperacillin-tazobactam (4.5 g every 6 hours), cefepime (2 g every 8 hours), ceftazidime (2 g every 8 hours), aztreonam (2 g every 8 hours), meropenem (1 g every 8 hours), or imipenem (500 mg every 6 hours).

If empiric coverage for MRSA or P aeruginosa is being administered to adults with CAP based on published risk factors without local etiological data, empiric coverage should be continued while culture data are obtained.

Corticosteroid therapy

Routine corticosteroid treatment is not recommended in adults with CAP (regardless of severity) or severe influenza pneumonia.

The ATS/IDSA CAP guidelines endorse the Surviving Sepsis Campaign recommendations on using corticosteroids in patients with CAP who have refractory septic shock.

Anti-influenza therapy

Anti-influenza treatment (eg, oseltamivir) should be prescribed to all adults with CAP, regardless of hospitalization status, who test positive for influenza.

Antibacterial therapy in patients with influenza

Standard antibacterial treatment should be initially prescribed to adults with clinical and radiographic evidence of CAP who test positive for influenza.

Treatment duration

The duration of antibiotic therapy should be guided by a validated measure of clinical stability, continued until stability is achieved for at least 5 days.

Follow-up chest imaging

Routine follow-up chest imaging is not recommended in adults with CAP whose symptoms have resolved within 5-7 days.

For more information, please go to Community-Acquired Pneumonia (CAP).

For more Clinical Practice Guidelines, please go to Guidelines.

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