Community Acquired Pneumonia Guidelines

COMMUNITY ACQUIRED PNEUMONIA GUIDELINES
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**	Macrolide: • 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) OR 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
Non-ICU
Recommendations:	Respiratory Fluoroquinolone OR β‑Lactam PLUS Macrolide: • cefotaxime, ceftriaxone, or ampicillin plus • ertapenem (selected patients) Alternative to the Macrolide: doxycycline Penicillin Allergy: use Respiratory Fluoroquinolone
ICU
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 OR Above β‑Lactam PLUS Aminoglycoside AND Azithromycin OR 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
Prevention
• 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
REFERENCES
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. 1/2019)

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