From the Guidelines
Streptococcus pneumoniae is the most common cause of community-acquired pneumonia in patients with Chronic Obstructive Pulmonary Disease (COPD) 1.
Common Causes of Community-Acquired Pneumonia in COPD Patients
- Bacterial pathogens:
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
- Legionella species
- Viral pathogens:
- Influenza
- Respiratory syncytial virus
- Coronavirus
Risk Factors for Specific Pathogens
- COPD/smoker: S. pneumoniae, H. influenzae, Moraxella catarrhalis, Legionella 1
- Underlying chronic heart or lung disease: Increased risk of severe pneumonia and mortality 1
Diagnostic Testing
- Chest radiograph
- Sputum Gram’s stain and culture (if drug-resistant bacteria or an organism not covered by usual empiric therapy options are suspected) 1
- Complete blood count and differential
- Routine blood chemistry testing
- Oxygen saturation assessment by oximetry 1
From the Research
Causes of Community-Acquired Pneumonia in COPD Patients
- The most common cause of community-acquired pneumonia (CAP) in patients with Chronic Obstructive Pulmonary Disease (COPD) is similar to that of non-COPD patients, with Streptococcus pneumoniae being a common bacteria isolated from patients with CAP and COPD 2.
- However, patients with COPD are at an increased risk of infection by Gram-negative bacilli, including Pseudomonas aeruginosa 3, 4.
- Pseudomonas aeruginosa is especially common in patients with serious or extremely serious COPD 4.
- Other common pathogens in COPD patients with CAP include Haemophilus influenzae, Klebsiella pneumoniae, Staphylococcus aureus, and Escherichia coli 4.
Comparison with Non-COPD Patients
- The most common pathogens in non-COPD patients with CAP are Streptococcus pneumoniae, Haemophilus influenzae, and atypical bacteria such as Mycoplasma pneumoniae and Chlamydia pneumoniae 5, 6.
- While Pseudomonas aeruginosa is a common pathogen in COPD patients with CAP, it is less common in non-COPD patients with CAP 4, 6.
Treatment Considerations
- Empiric treatment regimens for CAP in COPD patients should consider the most common pathogens, including Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus, depending on the severity of CAP and COPD 3.
- Antibiotic treatment should be based on the likely causative pathogen, the presence of risk factors for infection with resistant bacteria, and local resistance patterns 5, 6.