What are the guidelines for managing pneumonia?

Management of Community-Acquired Pneumonia

For community-acquired pneumonia, treatment should be stratified by severity and location of care: outpatients receive amoxicillin (or a macrolide if penicillin-allergic), hospitalized non-severe cases receive combination therapy with amoxicillin plus a macrolide, and severe cases requiring ICU admission receive IV ceftriaxone or cefotaxime plus a macrolide or respiratory fluoroquinolone. 1, 2

Outpatient Management (Community Setting)

Antibiotic Selection:

• Amoxicillin at higher doses (1 g three times daily) remains the preferred first-line agent for 7 days 1
• A macrolide (erythromycin 500 mg four times daily or clarithromycin 500 mg twice daily) is the alternative for penicillin-allergic patients 1
• For patients being referred to hospital where delays exceed 2 hours or illness is life-threatening, general practitioners should administer antibiotics immediately before transfer 1

Hospitalized Patients with Non-Severe CAP

Antibiotic Regimen:

• Combined oral therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) is the preferred approach for patients requiring hospital admission 1
• Most hospitalized patients can be adequately treated with oral antibiotics rather than IV 1

Monotherapy Considerations:

• Amoxicillin monotherapy is acceptable for: (1) previously untreated patients in the community, or (2) elderly/socially isolated patients admitted for non-clinical reasons who would otherwise be managed outpatient 1
• When oral therapy is contraindicated, use IV ampicillin or benzylpenicillin plus erythromycin or clarithromycin 1

Alternative Regimens:

• Respiratory fluoroquinolones (levofloxacin) are not first-line but provide alternatives for patients intolerant of penicillins or macrolides, or where Clostridium difficile concerns exist 1
• Recent data shows ceftriaxone 1 g daily achieves similar mortality outcomes to 2 g daily with lower C. difficile rates and shorter hospital stays in regions with low penicillin resistance 3

Severe CAP Requiring ICU Admission

Immediate Parenteral Therapy:

• Patients with severe pneumonia require immediate IV antibiotics after diagnosis 1
• Preferred regimen: IV ceftriaxone (1-2 g once daily) or cefotaxime (1 g three times daily) PLUS a macrolide (clarithromycin or erythromycin) 1, 2
• Alternative: A second or third generation cephalosporin (cefuroxime, ceftriaxone, or cefotaxime) combined with a macrolide 1

Alternative for β-lactam Intolerance:

• A respiratory fluoroquinolone with enhanced S. pneumoniae activity (levofloxacin) plus IV benzylpenicillin 1
• Levofloxacin is the only such fluoroquinolone currently licensed in the UK for this indication 1

ICU-Specific Considerations:

• ICU patients should be managed by specialists trained in intensive care and respiratory medicine 1
• Bronchoscopy can be valuable for removing secretions, obtaining cultures, and excluding endobronchial abnormalities 1

Supportive Care and Monitoring

Oxygen and Fluid Management:

• Maintain oxygen saturation >92% and PaO2 >8 kPa; high-concentration oxygen is safe in uncomplicated pneumonia 1
• In patients with COPD and ventilatory failure, guide oxygen therapy by repeated arterial blood gases 1
• Assess for volume depletion and provide IV fluids as needed 1
• Provide nutritional support in prolonged illness 1

Vital Sign Monitoring:

• Monitor temperature, respiratory rate, pulse, blood pressure, mental status, oxygen saturation, and FiO2 at least twice daily, more frequently in severe cases 1
• Remeasure CRP and repeat chest radiograph in patients not progressing satisfactorily 1

Route and Duration of Therapy

IV to Oral Transition:

• Switch from IV to oral antibiotics when clinical improvement occurs, temperature normalizes for 24 hours, and no contraindications to oral therapy exist 1
• Review route of administration daily, initially on the "post-take" round 1

Treatment Duration:

• 7 days of appropriate antibiotics for uncomplicated non-severe CAP managed in community or hospital 1, 2
• 10 days for severe microbiologically undefined pneumonia 1
• 14-21 days when Legionella, staphylococcal, or Gram-negative enteric bacilli are suspected or confirmed 1, 2

Failure to Improve

Clinical Review:

• Patients not improving as expected require careful review by an experienced clinician of history, examination, prescription chart, and investigation results 1
• Obtain repeat chest radiograph, CRP, white cell count, and further microbiological specimens 1

Antibiotic Modification:

• For non-severe pneumonia on amoxicillin monotherapy: add or substitute a macrolide 1
• For non-severe pneumonia on combination therapy: consider switching to a respiratory fluoroquinolone 1
• For severe pneumonia not responding to combination therapy: consider adding rifampicin 1

Follow-Up and Radiographic Assessment

Discharge Planning:

• Chest radiograph need not be repeated before discharge in patients with satisfactory clinical recovery 1
• Provide patient information about CAP at discharge or follow-up 1

Post-Treatment Follow-Up:

• Arrange clinical review at approximately 6 weeks with general practitioner or hospital clinic for all patients 1
• Obtain chest radiograph at 6 weeks for patients with persistent symptoms/signs or high malignancy risk (smokers, age >50 years) 1
• Consider bronchoscopy for patients with persisting signs, symptoms, and radiological abnormalities 6 weeks after completing treatment 1

Prevention

Vaccination:

• Influenza vaccination is recommended for high-risk groups: chronic lung/heart/renal/liver disease, diabetes, immunosuppression, and age >65 years 1, 2
• Pneumococcal vaccination is recommended for those aged ≥2 years at increased risk, though evidence for CAP prevention in at-risk groups is limited 1
• Both vaccines can be administered together at different sites 1
• Promote smoking cessation as it eliminates an important CAP risk factor 1, 2

Common Pitfalls

Drug-Resistant Streptococcus pneumoniae (DRSP):

• When using β-lactam/macrolide combinations for patients with DRSP risk factors, only specific β-lactams are appropriate: oral cefpodoxime, amoxicillin/clavulanate, high-dose amoxicillin, or cefuroxime; IV ceftriaxone, cefotaxime, ampicillin/sulbactam, or high-dose ampicillin 1
• Penicillin resistance has minimal impact on pneumonia mortality (unlike meningitis) because achievable serum/pulmonary levels exceed MICs several-fold 4

Macrolide Resistance:

• Patients infected with erythromycin-resistant pneumococci may not respond to macrolide monotherapy 4
• Erythromycin resistance rates of 10-15% have been documented 5

Avoiding Inappropriate Therapy:

• Inappropriate initial therapy (pathogen not sensitive to administered antibiotic) is a major mortality risk factor 1
• Modifying initially inadequate therapy after culture results does not improve outcomes—get it right the first time 6