Pneumonia is an infection of the lower respiratory airway/lung parenchyma by community acquired bacteria.
Most common agents:
Typical CAP: Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis.
Atypical CAP: Mycoplasma, Legionella, Chlamydia.
- Shortness of breath
- Chest pain on inspiration
- In atypical pneumonias the patient may have: headache, ear pain, diarrhea, rash
- Increased RR and HR
- Crackles/Rales on Auscultation
- Bronchial breathing
- Increased tactile fremitus
- Dullness to percussion
- Reduced breath sounds or Muffled sound (Pleural effusion)
- In severe cases: hypotension, altered mental status, signs of imminent respiratory failure
TESTS TO CONSIDER ORDERING:
- Chest X-Ray (usually consolidation in bacterial infections and diffuse infiltrates in viral infections)
- CBC, CMP, C-Reactive protein, Procalcitonin
- Arterial Blood Gases
- Blood cultures
- Sputum cultures
- Urine Antigen for Legionella and Streptococcus
- Bronchoalveolar Lavage
- If pleural effusion: Diagnostic thoracentesis (pH, GRAM stain, LDH, protein, ADA)
Suggestive clinical features + Infiltrate on the X-Ray.
MANAGEMENT & TREATMENT:
Assess severity and decide for outpatient or inpatient treatment using one of the following scores:
Outpatient/Low risk/No comorbidities: Macrolide (azithromycin, clarithromycin).
Outpatient with Comorbidities: Fluoroquinolone (Moxifloxacin, Levofloxacin) OR Macrolide + Beta-lactam (Amoxacilin or Amoxacilin+Clavulonate).
Inpatient: Beta-lactam/Cephalosporine (Ceftriaxone) + Macrolide OR Fluoroquinolone.
Inpatient with Risk/Suspicion for MRSA: Add Vancomycin or Linezolid.
Inpatient with risk/suspicion for Pseudomonas: Antipseudomonal Beta-lactam (Piperacilin-Tazobactam, Cefepime or Carbapenens) + Quinolone OR Antipseudomonal Beta-lactam + Aminoglicoside + Macrolide OR Aztreonam + Aminoglicoside + Quinolone.
Manage septic patients according to the sepsis protocol.
DISEASES THAT MAY PRESENT WITH SIMILAR SIGNS AND SYMPTOMS:
- Viral pneumonia
- Fungal pneumonia
- Lung vasculitis
SOURCES & REFERENCES, RESOURCES AND FURTHER READING:
- Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults
- CURB-65 Pneumonia Severity Score
- The role of procalcitonin in adult patients with community-acquired pneumonia–a systematic review.
- The Pneumonia Severity Index: A Decade after the Initial Derivation and Validation
- Community Acquired Pneumonia in Adults Guideline
- Pneumonia in adults: Diagnosis and Management
- Community-Acquired Pneumonia
- CURB-65 – Calculator
- PSI/PORT Score: Pneumonia Severity Index for CAP – Calculator