What are the current guidelines for managing community-acquired pneumonia (CAP)?

Current Guidelines for Community-Acquired Pneumonia Management

The current guidelines for community-acquired pneumonia (CAP) recommend initial empiric therapy with either a beta-lactam plus a macrolide, a respiratory fluoroquinolone alone, or macrolide monotherapy (in select cases), with treatment decisions based on severity assessment, risk factors, and local resistance patterns. 1

Assessment and Diagnosis

Severity Assessment

• Use the Pneumonia Severity Index (PSI) or CRB-65 score to determine site of care and treatment intensity 2, 1
• PSI risk classes I-III: consider outpatient management
• PSI risk classes IV-V or CRB-65 score ≥2: consider inpatient management
• Assess oxygenation status in all patients with pulse oximetry 1

Diagnostic Testing

• Collect specimens for microbiologic studies before initiating antibiotics, but do not delay the first antibiotic dose 1
• Recommended tests include:
  • Blood cultures (before antibiotics)
  • Sputum Gram stain and culture
  • Urinary antigen tests for Legionella and pneumococcus
  • Multiplex PCR testing when available 1

Empiric Antibiotic Therapy

Outpatient Treatment

1. Previously healthy patients with no recent antibiotic therapy:

   • Macrolide (azithromycin 500mg on day 1, then 250mg daily for days 2-5) OR
   • Doxycycline 100mg twice daily 1

2. Patients with comorbidities or recent antibiotic therapy:

   • Respiratory fluoroquinolone (levofloxacin 750mg daily or moxifloxacin 400mg daily) OR
   • Beta-lactam (high-dose amoxicillin, amoxicillin-clavulanate) plus a macrolide 1

Inpatient Treatment (Non-ICU)

• Beta-lactam plus macrolide OR
• Respiratory fluoroquinolone alone 1

ICU Treatment

• Beta-lactam plus either a macrolide or respiratory fluoroquinolone 1
• For patients at risk for Pseudomonas:
  • Antipseudomonal beta-lactam plus either ciprofloxacin/levofloxacin OR
  • Antipseudomonal beta-lactam plus aminoglycoside and azithromycin/fluoroquinolone 1
• For patients at risk for MRSA:
  • Add vancomycin or linezolid to standard regimen 1

Special Considerations

Antibiotic Selection

• If patient received antibiotics in the past 3 months, select an agent from a different class 1
• For penicillin-allergic patients, use a respiratory fluoroquinolone 1
• Never use macrolide monotherapy in HIV-infected patients due to increased risk of drug-resistant S. pneumoniae 1
• Use fluoroquinolones cautiously in HIV-positive patients when TB is suspected 1

Duration of Therapy

• Minimum treatment duration is 5 days 1
• Patient should be afebrile for 48-72 hours and have no more than one sign of clinical instability before discontinuation 1
• Consider switching to oral antibiotics when:
  • Hemodynamically stable
  • Clinically improving
  • Able to take oral medications
  • Normal gastrointestinal function 1

Monitoring and Discharge Criteria

Treatment Monitoring

• Evaluate response to treatment at 48-72 hours 1
• Monitor temperature, WBC, chest X-ray, oxygenation, sputum production, and hemodynamic status 1

Discharge Criteria

• Clinically stable (no more than 1 of the following: temperature >37.8°C, respiratory rate >24/min, heart rate >100/min, systolic blood pressure <90 mmHg, oxygen saturation <90%, altered mental status) 2, 1
• No other active medical problems requiring hospitalization
• Safe environment for continued care
• Ability to tolerate oral medication 1

Prevention

• Pneumococcal vaccination for high-risk individuals
• Annual influenza vaccination
• Smoking cessation counseling 1

Common Pitfalls and Caveats

1. Delayed antibiotic administration: Do not wait for diagnostic results before starting antibiotics in suspected CAP 1

2. Inappropriate antibiotic selection: Consider local resistance patterns when selecting empiric therapy 1

3. Fluoroquinolone risks: Be aware of potential adverse effects including tendon rupture, peripheral neuropathy, and C. difficile infection 1

4. Macrolide resistance: Increasing in many regions, potentially limiting effectiveness as monotherapy 1

5. Failure to de-escalate: Narrow antibiotic spectrum once pathogen is identified to reduce resistance development 3

6. Inadequate follow-up: Arrange clinical review for all patients at around 6 weeks, either with their general practitioner or in a hospital clinic 2

7. Unnecessary repeat imaging: The chest radiograph need not be repeated prior to hospital discharge in patients who have made a satisfactory clinical recovery 2