Community Acquired Pneumonia Guidelines

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Site-of-Care Decisions

• Determine if patient should be treated inpatient or outpatient

º Outpatient care: able to take oral medications and have adequate outpatient care

º Inpatient care: based on severity-of-illness scores (eg, CURB‑65 criteria [confusion, uremia, respiratory rate, low blood pressure, 65 years or older]) or prognostic models (eg, Pneumonia Severity Index [PSI]) and professional judgment

• Patients with CURB‑65 score ≥2 require hospitalization or aggressive outpatient care

• If inpatient treatment required, determine if patient should be admitted to ICU or general ward

º ICU admission required: septic shock necessitating vasopressors, or acute respiratory failure requiring intubation and mechanical ventilation

º ICU admission recommended: 1 major criteria or 3 minor criteria are present

Severe CAP Criteria
Minor Criteria

• Hypothermia (<36°C)

• PaO2/FiO2 ratio ≤250

• Leukopenia (WBC <4000 cells/mm³)

• Multilobar infiltrates

• Confusion/disorientation

• Respiratory rate ≥30 breaths/min

• Uremia (BUN ≥20mg/dL)

• Thrombocytopenia (platelets <100000 cells/mm³)

• Hypotension requiring aggressive fluid resuscitation

• Other considerations: hypoglycemia, acute alcoholism/alcoholic withdrawal, hyponatremia, unexplained metabolic acidosis, elevated lactate, cirrhosis, asplenia

Major Criteria

• Invasive mechanical ventilation

• Septic shock requiring vasopressors

Diagnostic Tests

• Physical exam:

º Crackles or rales, bronchial breath sounds, hypoxemia, tachypnic

º Signs/symptoms of cough, fever, sputum production, pleuritic chest pain

• Chest radiograph:

º Observe apparent lobar or bilateral infiltrates with or without microbiological evidence

º Hospitalized for suspected pneumonia but negative chest radiograph: may receive empiric antibiotics with repeat chest radiograph 24−48hrs later

• Lab tests:

º Pretreatment blood culture and/or expectorated sputum samples for culture and gram stain should be taken if: ICU admission, outpatient antibiotic therapy failure, cavitary infiltrates, leukopenia, active alcohol abuse, chronic severe liver and lung disease, asplenia, positive Legionella or pneumococcal UAT result, pleural effusion; optional for other indications

º Tests mentioned above are optional in patients without these conditions

• Pulse oximetry

• Severe CAP: should obtain blood culture, expectorated sputum culture, urinary antigen tests for Legionella pneumophila and S. pneumoniae; endotracheal aspirate sample for intubated patients

• Nonresponsive to antibiotics: chest CT, thoracentesis, bronchoscopy with BAL and transbronchial biopsies to rule out other reasons for antibiotic failure

• Diagnostic tests to determine etiology are optional for outpatients

Outpatient Empirical Treatment

Previously healthy with no risk factors for drug-resistant S. pneumoniae (DRSP) infection or no use of antimicrobials within previous 3 months


• azithromycin, clarithromycin, or erythromycin

Alternative: doxycycline

Comorbid conditions:

Diabetes, chronic heart, lung, liver, or renal disease, alcoholism, malignancies, asplenia, immunosuppressive conditions or drugs, use of antimicrobials in the previous 3 months, or other risks for DRSP infection

Respiratory Fluoroquinolone:

• moxifloxacin, gemifloxacin, or levofloxacin (750mg)


β‑Lactam PLUS Macrolide:

• amoxicillin (1g three times daily) or

• amoxicillin/clavulanate (2g twice daily) or

• cefpodoxime, ceftriaxone, or cefuroxime (500mg twice daily) plus

• azithromycin, clarithromycin, or erythromycin

Alternative to the Macrolide: doxycycline

Regions with high rate (>25%) of macrolide-resistant S. pneumoniae

Consider alternative agents:

• eg, β‑Lactam or Respiratory Fluoroquinolone

Inpatient Empirical Treatment


Respiratory Fluoroquinolone




β‑Lactam PLUS Macrolide:

• cefotaxime, ceftriaxone, or ampicillin plus

• ertapenem (selected patients)


Alternative to the Macrolide: doxycycline


**Penicillin Allergy**: use Respiratory Fluoroquinolone


Minimal Recommendations:

β‑Lactam PLUS Azithromycin OR Fluoroquinolone:

• cefotaxime, ceftriaxone, ampicillin/sulbactam


**Penicillin Allergy**: a Respiratory Fluoroquinolone AND Aztreonam are recommended

Additional Recommendations or Modifications:

 If Pseudomonas Infection

Antipneumococcal Antipseudomonal β‑Lactam* PLUS Ciprofloxacin OR Levofloxacin (750mg):

• piperacillin-tazobactam, cefepime, imipenem, meropenem




*Above β‑Lactam PLUS Aminoglycoside AND Azithromycin




*Above β‑Lactam PLUS Aminoglycoside AND Antipneumococcal Fluoroquinolone

**Penicillin Allergy**: substitute Aztreonam for above β‑Lactam

 If Community-Acquired Methicillin-Resistant S. aureus (CA‑MRSA)

Add vancomycin or linezolid

Pathogen Specific Treatment

S. pneumoniae PCN susceptible (MIC <2µg/mL)

Preferred: penicillin G, amoxicillin

Alternative: macrolide, cephalosporins (cefpodoxime, cefprozil, cefuroxime, cefdinir, ceftriaxone, cefotaxime), clindamycin, doxycycline, respiratory fluoroquinolone

S. pneumoniae PCN resistant (MIC ≥2µg/mL)

Preferred: based on susceptibility including cefotaxime, ceftriaxone, fluroquinolone

Alternative: vancomycin, linezolid, high-dose amoxicillin (3g/day with PCN MIC ≤4µg/mL)

H. influenzae non-β-lactamase producing

 Preferred: amoxicillin

Alternative: fluoroquinolone, doxycycline, azithromycin, clarithromycin

H. influenzae β-lactamase producing

Preferred: 2nd or 3rd generation cephalosporin, amoxicillin/clavulanate

Alternative: fluoroquinolone, doxycycline, azithromycin, clarithromycin

Legionella species

Preferred: fluoroquinolone, azithromycin

Alternative: doxycycline

Mycoplasma pneumoniae, Chlamydophila pneumoniae

Preferred: macrolide, tetracycline

Alternative: fluoroquinolone

Influenza A

Preferred: initiate oseltamivir or zanamivir within 48hrs if influenza A identified. Not recommended if uncomplicated influenza and symptoms ongoing for >48hrs.

H5N1 Influenza

Preferred: oseltamivir 75mg twice daily for 5 days

Other Treatments

• Consider local resistance patterns, previous antibiotic use, and comorbidities when choosing empirical antibiotics

• Administer noninvasive ventilation in cases of hypoxemia or respiratory distress unless immediate intubation necessary due to severe hypoxemia or bilateral alveolar infiltrates

• Low-tidal-volume ventilation (6cm³/kg of IBW) for patients with diffuse bilateral pneumonia or acute respiratory distress syndrome

• Screen for occult adrenal insufficiency in hypotensive fluid-restricted patients with severe CAP

Treatment Duration

• Admission through Emergency department: administer 1st antibiotic dose in the ED

• Initiate treatment within 6−8hrs of presentation

• Duration: minimum 5 days of treatment, should be afebrile 48−72hrs, and no more than 1 CAP associated sign of clinical instability before discontinuing therapy

• Longer duration of therapy may be warranted in certain circumstances (eg, initial therapy did not target identified pathogen, extrapulmonary infections such as meningitis or endocarditis)

IV to Oral Switch

• Switch once hemodynamically stable, notable clinical improvement, normal functioning GI tract, and can ingest oral therapy

• Usually switch to oral form of same antibiotic or same pharmacological class

• Discharge once clinically stable, no other active medical problems, and have a safe environment for continued care as an outpatient

• Criteria for Clinical Stability:

º Temp ≤37.8°C

º Heart rate ≤100 beats per min

º Respiratory rate ≤24 breaths per min

º Systolic blood pressure ≥90mmHg

º Arterial 02 saturation ≥90% or pO2 ≥60mmHg

º Maintain oral intake and normal mental status


• Smoking cessation should be advised in hospitalized patients

• Assess vaccination status at time of hospital admission

• Inactivated influenza vaccine recommended for all children 6−23 months and ≥50 years of age, high risk persons 6 months–49 years of age, household contacts of high-risk persons, healthcare workers, pregnancy, diabetes, asthma

• Pneumococcal vaccine recommended for persons ≥65 years of age, high-risk persons 2−64 years of age, smokers, diabetes, asplenia, alcoholism, chronic cardiovascular, pulmonary, renal, or liver disease

• Offer influenza vaccine administration during discharge or outpatient treatment; vaccines can be given during either time


Mandell LA, Wunderink RG, Anzueto A, et. al. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. IDSA/ATS. 2007; 44 Suppl 2: S27−S63.

(Rev. 11/2017)

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