Assessment and Plan for Community-Acquired Pneumonia
The management of community-acquired pneumonia (CAP) should be guided by severity assessment using validated tools like CURB-65 or Pneumonia Severity Index to determine the appropriate treatment setting and antibiotic regimen. 1, 2
Initial Assessment
Severity Assessment
Use CURB-65 criteria (each worth 1 point):
- Confusion
- Urea >7 mmol/L (BUN >19 mg/dL)
- Respiratory rate ≥30/min
- Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
- Age ≥65 years
Major criteria for severe CAP (requiring ICU admission) 1:
- Septic shock requiring vasopressors
- Respiratory failure requiring mechanical ventilation
Diagnostic Testing
Based on treatment setting:
Outpatient Management
- Chest radiograph (if available)
- Pulse oximetry
- No routine blood cultures recommended 1
Non-severe Inpatient Management
- Chest radiograph
- Complete blood count
- Basic metabolic panel
- Liver function tests
- C-reactive protein
- Pulse oximetry or arterial blood gas
- Blood cultures (not routinely recommended but consider in specific situations) 1
Severe Inpatient Management
- All of the above plus:
- Blood cultures (mandatory before antibiotics) 1
- Sputum culture (if purulent sample available)
- Legionella and pneumococcal urinary antigen tests 1
- Consider respiratory pathogen PCR panel
Treatment Plan
Outpatient Management
Without Comorbidities
With Comorbidities (chronic heart/lung/liver/renal disease, diabetes, alcoholism, malignancy)
- First-line: Combination therapy with amoxicillin-clavulanate (875/125mg twice daily) plus a macrolide
- Alternative: Respiratory fluoroquinolone monotherapy (levofloxacin 750mg daily for 5 days) 1, 2, 3
Non-severe Inpatient Management
- First-line: β-lactam (ceftriaxone 1-2g daily or ampicillin-sulbactam 1.5-3g every 6 hours) plus macrolide (azithromycin 500mg daily) 1, 2
- Alternative: Respiratory fluoroquinolone monotherapy (levofloxacin 750mg daily) 1, 3
Severe Inpatient Management (ICU)
- Standard regimen: β-lactam (ceftriaxone, cefotaxime) plus either macrolide or respiratory fluoroquinolone 1
- If MRSA risk: Add vancomycin or linezolid 1
- If Pseudomonas risk: Use antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, meropenem) plus either fluoroquinolone or aminoglycoside 1, 4
Special Considerations
Risk Factors for Drug-Resistant Pathogens
- Prior MRSA or Pseudomonas infection
- Hospitalization and parenteral antibiotics in the last 90 days 1
- Structural lung disease (bronchiectasis, COPD)
- Recent antibiotic use
Duration of Therapy
- Outpatient: 5-7 days 2
- Non-severe inpatient: 7 days 1, 2
- Severe inpatient: 7-10 days 2
- If Pseudomonas or MRSA: 10-14 days 2
Patients should be afebrile for 48-72 hours with no more than one sign of clinical instability before discontinuing therapy 2.
Monitoring and Follow-up
Outpatient
- Clinical review at 48 hours or sooner if clinically indicated 1, 2
- Assess for improvement in symptoms (fever, cough, dyspnea)
- Consider hospitalization if not improving or worsening
Inpatient
- Monitor vital signs, mental status, and oxygen saturation at least twice daily 1, 2
- Measure CRP in patients not progressing satisfactorily 1
- Consider treatment failure if no clinical improvement within 72 hours 5
Follow-up After Treatment
- Clinical review approximately 6 weeks after discharge 2
- Follow-up chest radiograph not necessary in patients with satisfactory clinical recovery but should be considered in patients with persistent symptoms or risk factors for malignancy 2
Prevention
- Annual influenza vaccination for all at-risk patients 1, 2
- Pneumococcal vaccination for individuals ≥65 years and those with high-risk conditions 2
- Smoking cessation counseling 2
Common Pitfalls to Avoid
- Delaying antibiotics in severe CAP (should be given within 1 hour of diagnosis)
- Using macrolide monotherapy in areas with high pneumococcal resistance
- Failing to reassess patients at 48-72 hours for treatment response
- Unnecessary prolonged courses of antibiotics
- Overuse of fluoroquinolones when narrower-spectrum options are appropriate
- Failing to consider non-infectious causes in patients who don't respond to treatment 5